Gen V - Pushrod Engines for the Future

[dwightlooi]

Generation V - Pushrods for the Future

The pushrod layout is chosen for the following reasons:-

o In the interest of fuel economy, engines should have minimum internal friction.

o In the interest of fuel economy, it is better to decrease cylinder count than to decrease displacement.

o In the interest of performance, engines should have best in class power-to-weight ratios.

o In the interest of packaging, engines should have best in class power-to-size (external dimension) ratios.

o Advanced Technology like Direct Injection, Independent VVT and roller followers can be applied to pushrod engines

Gen V 6.2 V8s have the highest power-to-weight and power-to-size (external dimensions) of any mass production V8 in their power class. They also have the lowest fuel consumption in their power class. Gen V 4.7 liter V6es replaces the 4.2 liter I6, 4.8 liter V8 & 5.3 liter V8 with a physically more compact engine that boasts similar power and torque output while reducing fuel consumption. The Gen V pushrod four cylinder is essentially a V8 with one bank of cylinders. It replaces the DOHC 2.9L Inline four with an engine with both improved performance and enhanced fuel economy. All Gen V engines can be manufactured on the same production line using shared tooling and assembly procedures.

[Lamar]

I imagine that 6.2 wouldn't be the only displacement available for the car engines? (5.5L is still the number I see thrown around the most)

[regfootball]

why would you bother with a pushrod 6 and 4

[dwightlooi]

why would you bother with a pushrod 6 and 4

Developed on their own, no. They are not worth the effort. But as derivatives of a V8 they are a relatively low cost means of getting a big displacement six or a big displacement four. The intent is that a 3.1 liter pushrod four may be a better engine than the current 2.4 liter DOHC four, 2.9 liter DOHC four or 3.0 DOHC V6 when used in light trucks. The 3.1 liter four promises over 210 lb-ft of torque and should have better economy numbers than a 3.0 liter V6. Similarly, a 4.7 liter V6 offers the same basic performance and towing capabilties as today's 5.3 V8 while possibly offering fuel economy number close to that of a 3.6 liter DOHC V6.

[Carguy]

If you do a 6.0L V8 for the trucks that would translate to a 4.5L V6 and a 3.0L I4 that would sound better and space apart better also. I thought of this 4.5L V6 as a replacement for the aging 4.3L V6 long ago as they came out with today's 6.0L SB. I like your idea of a OHV I4 also and as a new and compact line of truck engines they could work great. For car usage I could also see a 5.5L V8 both supercharged and not and with it a premium 6.0L 3VPC version specially tuned for smoothness and quietness for Cadillac. And thinking beyond that and to offer Cadillac a unique line of engines do a premium 4.5L 3VPC V6 version for them also as a more torquey and most likely more efficient with AFM replacement for the 3.6L V6. Let Cadillac be something unique and be powered by something unique from other GM brands.---Again I like the way you think!!

[dwightlooi]

If you do a 6.0L V8 for the trucks that would translate to a 4.5L V6 and a 3.0L I4 that would sound better and space apart better also. I thought of this 4.5L V6 as a replacement for the aging 4.3L V6 long ago as they came out with today's 6.0L SB. I like your idea of a OHV I4 also and as a new and compact line of truck engines they could work great. For car usage I could also see a 5.5L V8 both supercharged and not and with it a premium 6.0L 3VPC version specially tuned for smoothness and quietness for Cadillac. And thinking beyond that and to offer Cadillac a unique line of engines do a premium 4.5L 3VPC V6 version for them also as a more torquey and most likely more efficient with AFM replacement for the 3.6L V6. Let Cadillac be something unique and be powered by something unique from other GM brands.---Again I like the way you think!!

Thought about that. But, if we are going for maximum commonality and have to share a single bore & stroke, the logic goes that a pushrod V8's architectural advantage is the greatest when displacement is maximized. The same thing goes for V6es and I4s when it comes to fuel economy.

Actually, the original "Passenger Car" table has three columns. There was originally a V8 just for Caddy exclusively. This has a traditional cross plane crank, dual VVT, DI, Cylinder De-activation and a BALANCE SHAFT under the high mounted camshaft to damp out residual end to end vibration on cross plane V8s. This is the "Serene V8" and it should make about 430~450 hp. Vette and Camaro SSes were supposed to get a more ranchous V8 making 480 hp NA. This has cylinder de-activation deleted and uses a flat plane crank with no balancer! I decided that it is one too many engine and a compromised "universal 6.2" may be a better idea.

Edited July 4, 2010 by dwightlooi

[loki]

the 4.3L certainly should be replaced, but 10% bigger?

i do see why you want to simplify it all, but wouldn't just alittle modification be needed to update the 3.5/3.9L block, and give 280+hp in a ~3.9 variant and be inherently smoother with the 60 degree bank?

the perception of the OHV 4 seems like you'd have to show a REAL benefit over ohc engines, not 1 mpg but more, show it's smoother, ... sounds like it'll have more power.

i know you've adressed it several times, any advantage for moving forward with a 3valve design?

[dwightlooi]

the 4.3L certainly should be replaced, but 10% bigger?

i do see why you want to simplify it all, but wouldn't just alittle modification be needed to update the 3.5/3.9L block, and give 280+hp in a ~3.9 variant and be inherently smoother with the 60 degree bank?

the perception of the OHV 4 seems like you'd have to show a REAL benefit over ohc engines, not 1 mpg but more, show it's smoother, ... sounds like it'll have more power.

i know you've adressed it several times, any advantage for moving forward with a 3valve design?

(1) If you have a 60 deg V6, it is a separate engine line. The reason 90 deg V6es exists for the most parts is because it can be built together with the 90 deg V8s. Once the 3.5 and 3.9 retires, an all 90 deg lineup simplifies production and logistics.

(2) A 3.1 liter Pushrod-4 will not be smoother than an OHC design, although it won't be any worse than a 2.9~3.1 liter class SOHC or DOHC four. It won't be dramatically more efficient than a 2.9 DOHC either and may in fact be less economical than a SOHC 8v four of the same displacement. It will however be more efficient than a 3.0 liter six and that is it's mission. And, with dual balancers, it is livable in terms of vibrations, especially since it is used exclusively in entry level trucks. If you ever want to experience a 3 liter four you can try out a Colorado with the 2.9 I-4 or... heh... a Porsche 968 (or late production 944) if you can find one!

[Carguy]

I think you should have kept the Cadillac "serene" V8 being they need it badly in there lineup. With the death of the Northstar and the CTS needing something between the V6 models and the V series along with an engine for the upcoming large Cadillac beyond the XTS its needed. And with the worries about fuel economy a smaller displacement and supercharged version could be done like todays 6.2L is at say 5.0L's and 475-500HP for the Vette and top Camaro. And I still like the idea of a related large capacity V6 version for Cadillac more premium in scope then the truck version. Like the OHV Bentley 6.75L V8 thats continually refined and developed a refined,quiet and torquey Cadillac OHV line of engines would be majestic and unique in the luxury car market. Some people would scoff at an OHV Cadillac engine thinking DOHC is superior until they drove one and felt its surge of low end torque that would be uniquely American in nature as Cadillac should be. I like you believe there is still a place for the venerable OHV tech using modern DI AFM ect in more then only trucks and Cadillac would be that place.

[smk4565]

why would you bother with a pushrod 6 and 4

Or a pushrod 8 for that matter. The cylinder count doesn't matter, more cams and valves is better than less cams and valves.

Plus we already know the next generation V8 is a 5.5 liter with 430-440 hp for the Corvette, thus probably 400ish for the trucks if it is geared more for torque. So most of these engine options probably won't exist, the CTS-V, Z06 and ZR1 will probably just have a supercharged 5.5 liter.

The XTS is front drive, so a V8 is pointless there (that is like an 06 Impala SS). Then you have to wonder if the next generation CTS and Camaro being on Alpha, if they will stick with V6 and turbo V6 engines. GM is moving away from V8s on larger car platforms, will they put one on a small car platform?

[smk4565]

Cadillac without a DOHC V8 is dead, even Hyundai has one, and they have a second version with 425 hp coming next year.

If GM needs torque and fuel economy for the pickups, diesel is the way to go. Why mess around with pushrod derivatives of an old engine design, making 4.7 liter engines with 300 lb-ft when a 3.0 liter diesel can make 425 lb-ft. The Jaguar XF diesel puts out 442 lb-ft, that is better than GM's 6.2 liter V8. And the 6.2 V8 can't get 35 mpg on the highway.

[dwightlooi]

This was the "Serene" V8

[dwightlooi]

Cadillac without a DOHC V8 is dead, even Hyundai has one, and they have a second version with 425 hp coming next year.

If GM needs torque and fuel economy for the pickups, diesel is the way to go. Why mess around with pushrod derivatives of an old engine design, making 4.7 liter engines with 300 lb-ft when a 3.0 liter diesel can make 425 lb-ft. The Jaguar XF diesel puts out 442 lb-ft, that is better than GM's 6.2 liter V8. And the 6.2 V8 can't get 35 mpg on the highway.

It is not what GM needs for pickups, or what Hyundai does or does not have.

It is that GM ought to consider an engine that is:-

• Physically more compact and lighter than a DOHC engine of similar output.
  
• More Economical than a DOHC engine of similar output.
  
• Is unique to GM.
  
• Can be applied across a wide array of applications.
  

No, a 6.2 V8 will not get 35 MPG. Neither will DOHC designs including Toyota's 4.6, Hyundai's 4.6, BMW's 4.4 (turbo), Mercedes' 5.5, Ford's 5.0, Audi's 4.2, Nissan's 5.6. A 6.2 Pushrod V8 however can have MPG numbers that is slightly BETTER than the best of these engines, and significantly better than some of them.

The only argument against a pushrod engine is that it is somewhat low tech and uncivil. A design using dual VVT, direct injection and cylinder deactivation is not low tech. And, if you successfully benchmark a Bentley 6.75 liter Pushrod V8 you are pretty darn civil.

[Carguy]

That "serene" V8's 450HP and 432FT,LB of Torque would be out right killer compared to its competitors as would a 335HP and 315T large yet efficient serene V6 with the same Bore/Stroke! Cadillac would be KING for years to come when it comes to power without the cost of a new,expensive and less efficient DOHC V8 while letting Buick and Chevrolet use the 3.0L-3.6L HFV6. Return Cadillac to something uniquely American in focus and purpose with this new SERENE Engine line!!!

[balthazar]

I'll again advocate a separate engine exclusively for Cadillac- the segment demands it. I strongly support the 'Serene V8' proposal (different name, tho ).

[dwightlooi]

I'll again advocate a separate engine exclusively for Cadillac- the segment demands it. I strongly support the 'Serene V8' proposal (different name, tho ).

LOL... how about the Cadillac "Symphony V8"

Cruising along at 1600 rpm at 60mph -- riding on roller rockers and roller lifters, with direct injection metering fuel, dual concentric VVT trimming out the overlap, dual length runners routing air through the long runners and (as a first among contemporary V8s) a single contra-rotating balancer damping out residual end-to-end rock of a 90 deg cross plane engine -- there isn't a lot to hear or feel though.

Edited July 5, 2010 by dwightlooi

[smk4565]

It is not what GM needs for pickups, or what Hyundai does or does not have.

It is that GM ought to consider an engine that is:-

• Physically more compact and lighter than a DOHC engine of similar output.
  
• More Economical than a DOHC engine of similar output.
  
• Is unique to GM.
  
• Can be applied across a wide array of applications.
  

The only argument against a pushrod engine is that it is somewhat low tech and uncivil. A design using dual VVT, direct injection and cylinder deactivation is not low tech. And, if you successfully benchmark a Bentley 6.75 liter Pushrod V8 you are pretty darn civil.

On the first point, then why not a pushrod V6 or a pushrod I4. A pushrod V6 would have smaller dimensions than a DOHC V6, and it would also be unique to GM. No one here can make an argument that a pushrod V6 is better than the 3.6 DI Cadillac uses, or the 3.7 liter Infiniti V6. The argument doesn't change for V8s, DOHC is still superior.

The Bentley V8 is a dinosaur that gets 12 mpg, and struggles to pass emissions standards. It is a torque monster, but the redline is also around 4500 rpm, and compare the Bentley 6.75 liter V8 to Merc's AMG V12. The Mercedes V12 matches it in torque and beats it by a big margin in hp. Bentley makes the fastest trucks around, but Cadillac isn't competing against them, they are competing against Lexus, BMW and Mercedes (or are supposed to be).

[balthazar]

Mercedes V-12 is a dinosaur that gets 11 MPG and struggles to pass emissions. It's days are also numbered as mercedes limits future installations.

Biggest problem by far is dressing a $200K, 600HP V12 sedan in the exact same trim as the $87K, 295HP V6 sedan. Cheap, very cheap.

[smk4565]

Mercedes V-12 is a dinosaur that gets 11 MPG and struggles to pass emissions. It's days are also numbered as mercedes limits future installations.

Biggest problem by far is dressing a $200K, 600HP V12 sedan in the exact same trim as the $87K, 295HP V6 sedan. Cheap, very cheap.

What is cheap about it? The trim isn't exactly the same, there are more options and features, plus upgraded leather, different seats, suede headliner, upgraded brakes, wheels, etc. There is more interior difference in an S65 and an S400 hybrid than there is in a base Corvette and a ZR-1. Percentage wise, the ZR-1 and base Corvette are farther apart than an S65 and a base S-class, and at least the S-class adds equipment and upgrades the interior. The ZR-1 adds head up display and some leather on the dash to replace the Cobalt level plastic that normally lives there.

The Bentley V8 is going on 60 years of usage, that is a dinosaur. And I am a Bentley fan (of real Bentleys anyway, not the phony Audi A8 Bentleys). Mercedes has been making V12s for 20 years, and the S65's V12 is in its 7th year. And that engine may leave soon, but I'm sure AMG will come up with something good for the future. Plus that is what this thread is about, a future GM engine, and how the 5.3 and 6.2 liter V8s are going to get replaced.

[Lamar]

What is cheap about it? The trim isn't exactly the same, there are more options and features, plus upgraded leather, different seats, suede headliner, upgraded brakes, wheels, etc. There is more interior difference in an S65 and an S400 hybrid than there is in a base Corvette and a ZR-1. Percentage wise, the ZR-1 and base Corvette are farther apart than an S65 and a base S-class, and at least the S-class adds equipment and upgrades the interior. The ZR-1 adds head up display and some leather on the dash to replace the Cobalt level plastic that normally lives there.

Mercedes-Benz's own website says and shows otherwise. Only interior option you can get on the S600/S65 that isn't available on the S400 is the upgraded leather. AMG upgrades on the S65 are, well, obvious.

Also, about the percentages...

The ZR1 is 218% the price of the base Corvette coupe.

The S65 AMG is 228% the price of the S400 Hybrid.

The Bentley V8 is going on 60 years of usage, that is a dinosaur. And I am a Bentley fan (of real Bentleys anyway, not the phony Audi A8 Bentleys). Mercedes has been making V12s for 20 years, and the S65's V12 is in its 7th year. And that engine may leave soon, but I'm sure AMG will come up with something good for the future. Plus that is what this thread is about, a future GM engine, and how the 5.3 and 6.2 liter V8s are going to get replaced.

Then why are you arguing (incorrectly) about differences in interiors?

[smk4565]

If you use a loaded ZR-1 which is $120,000, then the ZR-1 is a 245% increase over the base car. Where as the S65 has no options. So the gap from absolute base model to top end is still greater on the Corvette. But every car maker does essentially the same thing, offering upgraded of special versions of the basic car, that is where the profit is.

But balthazar brings up a good point, Mercedes charges $90k for a 295 hp V6 sedan. Cadillac could build a sedan with 600 hp and not get $90k for it. Cadillac has to do more to break away from mainstream GM, otherwise they are no different than Lincoln or Acura. Part of that breaking away is not using the same engine in the Silverado.

[dwightlooi]

On the first point, then why not a pushrod V6 or a pushrod I4. A pushrod V6 would have smaller dimensions than a DOHC V6, and it would also be unique to GM. No one here can make an argument that a pushrod V6 is better than the 3.6 DI Cadillac uses, or the 3.7 liter Infiniti V6. The argument doesn't change for V8s, DOHC is still superior.

The Bentley V8 is a dinosaur that gets 12 mpg, and struggles to pass emissions standards. It is a torque monster, but the redline is also around 4500 rpm, and compare the Bentley 6.75 liter V8 to Merc's AMG V12. The Mercedes V12 matches it in torque and beats it by a big margin in hp. Bentley makes the fastest trucks around, but Cadillac isn't competing against them, they are competing against Lexus, BMW and Mercedes (or are supposed to be).

Actually, there are advantages to a Pushrod V6 over a DOHC V6. These being that, like a pushrod V6, it is smaller and lighter than a DOHC V6 of similar output and it can have better fuel economy through comparatively lower internal friction. The reason DOHC I4s and DOHC V6es are preferred are three fold. The first being the fact that many countries tax vehicles based on displacement. DOHC engines have higher specific output -- that is, they have higher horsepower and torque numbers per unit displacement. It is advantageous for most economy cars and family haulers to be taxed less while offering a given amount of power. The second being that I4s and V6es, unlike I6es and 90 deg V8s are not well balanced unless additional measures are taken to balance them via balancer shaft(s). The problem with balance gets worse with increased reciprocating mass and stroke. This tends to get worse with displacement. Hence, with V6es and I4s civility tends to suffer worse than with V8s if you adopt a big displacement solution (pushrod or not). This is why really big engines tend to be I6es, V8s or V12s -- the first and last having perfect natural balancer and the V8 being very well balanced simply through the use of a cross plane crank and heavy counter weights because the pistons on the other bank balances the counterweights. Lastly, one of the biggest reasons for a pushrod layout is superior compactness in a 90 deg V8 because the heads are very compact and narrow compared to DOHC designs. In an I4 there is no packaging advantage whatsoever. In a 60 deg V6 the advantage is much less significant because a 60 deg engine is already narrow.

None of the above are particularly important for light trucks.

[Mike The Canadian]

On the first point, then why not a pushrod V6 or a pushrod I4. A pushrod V6 would have smaller dimensions than a DOHC V6, and it would also be unique to GM. No one here can make an argument that a pushrod V6 is better than the 3.6 DI Cadillac uses, or the 3.7 liter Infiniti V6. The argument doesn't change for V8s, DOHC is still superior.

The Bentley V8 is a dinosaur that gets 12 mpg, and struggles to pass emissions standards. It is a torque monster, but the redline is also around 4500 rpm, and compare the Bentley 6.75 liter V8 to Merc's AMG V12. The Mercedes V12 matches it in torque and beats it by a big margin in hp. Bentley makes the fastest trucks around, but Cadillac isn't competing against them, they are competing against Lexus, BMW and Mercedes (or are supposed to be).

I think the argument does change for a V8.

DOHC engines have larger frictional losses.

Another 2 cylinders adds a whole lot of parts.

Heck it's another 8 valves!

A lot of it is perception and pointless numbers like "hp/liter".

Even the fuel efficiency ratings are bs, my "archaic" pushrod V6 has been earning me 28 mpg combined.

By new government standards it's rated at 21 mpg combined. Around town accelerating 2000-2500 rpm is a breeze

thanks to the availability of low end torque. Add the fact that a 115 km/h cruise is done at 2000 rpms. A lot of

crap is perception man. Don't get me wrong, the pushrods of yesteryear were generally out-dated, mine included. However, by no means is it

not possible to have a pushrod engine that makes good power and achieves good mileage. GM just hasn't put in the time or money to do so.

To be completely honest, look at the DI 2.4, my 10+ year old V6 gets simular power, more torque and by my personal experience, better mileage.

However the mileage is really subjective to driving habits, push the V6 hard and beat on it all the time it's going to waste more gas. This is just comparing an engine

that was designed and barely changed from the early 90's all the way to the late 2000's to one that's revered as one of the better engines of today.

This isn't a knock on the 2.4 but rather trends I've been noticing. Lets get the same power and mileage of a V6, but with an I4 and somehow it's a good thing...

Either way, a lot of things are perception, but the reality is GM has to follow the herd because there will always be people who turn away over stupid crap like this.

Then again, I personally wouldn't complain, and an engine (IBC or SOHC, DOHC etc) has never caused me to turn away because of it's configuration. More like things such as

power curves, sound (I like my engines throaty), mileage etc.

[dwightlooi]

I think the argument does change for a V8.

DOHC engines have larger frictional losses.

Another 2 cylinders adds a whole lot of parts.

Heck it's another 8 valves!

A lot of it is perception and pointless numbers like "hp/liter".

Even the fuel efficiency ratings are bs, my "archaic" pushrod V6 has been earning me 28 mpg combined.

By new government standards it's rated at 21 mpg combined. Around town accelerating 2000-2500 rpm is a breeze

thanks to the availability of low end torque. Add the fact that a 115 km/h cruise is done at 2000 rpms. A lot of

crap is perception man. Don't get me wrong, the pushrods of yesteryear were generally out-dated, mine included. However, by no means is it

not possible to have a pushrod engine that makes good power and achieves good mileage. GM just hasn't put in the time or money to do so.

To be completely honest, look at the DI 2.4, my 10+ year old V6 gets simular power, more torque and by my personal experience, better mileage.

However the mileage is really subjective to driving habits, push the V6 hard and beat on it all the time it's going to waste more gas. This is just comparing an engine

that was designed and barely changed from the early 90's all the way to the late 2000's to one that's revered as one of the better engines of today.

This isn't a knock on the 2.4 but rather trends I've been noticing. Lets get the same power and mileage of a V6, but with an I4 and somehow it's a good thing...

Either way, a lot of things are perception, but the reality is GM has to follow the herd because there will always be people who turn away over stupid crap like this.

Then again, I personally wouldn't complain, and an engine (IBC or SOHC, DOHC etc) has never caused me to turn away because of it's configuration. More like things such as

power curves, sound (I like my engines throaty), mileage etc.

I think one point that most people are missing is this...

• An engine's breathing ability has very little, if anything, to do with fuel economy!
  

Sounds counter intuitive? Not really.

Let's look at it this way. Picture yourself moving a plunger inside a syringe. An engine's cylinder is similar. The small hole on top of the syringe causes resistance as you try to pump air in and out with the plunger. If you cut off the top of the syringe such that it is essentially an open ended cylinder, you'll have perfect volumetric efficiency -- perfect breathing with no restrictions -- and the only resistance comes from the friction between the plunger and the walls. Now picture a DOHC 4-valve engine as one with a bigger hole on top and a push rod 2-valve engine as one with a smaller hole. Naturally, as you work the plunger the syringe with a bigger hole has less resistance. In an engine this translate to lower pumping losses, more air being aspirated and more power! However, this is under wide open throttle conditions!

Now... picture attaching a rubber tube to both syringes and pinching the tube to constrict flow. That is exactly what the throttle plate does at all driving conditions except when you are flooring it. Therefore, at cruise and under moderate driving conditions, any intake restriction not present in the intake and through the valves is intentionally introduced by the throttle body! If your car doesn't do this, it needs to be recalled for a "stuck accelerator pedal". Therefor intake side restrictions of any engine typically does not introduce additional pumping losses at cruise and does not impact fuel economy.

Now, we are talking about intake restictions of course. On the exhasut side there is no throttle plate. However, exhaust under pressure self-aspirate quite easily even through one valve or valves with less opening. And, exhaust restrictions, while ever present typically does not impact power or economy until reasonably high up in the rev range (4000~5000 rpm or so). At cruise and under moderate driving conditions the impact is minimal.

Edited July 7, 2010 by dwightlooi

[Carguy]

The problem that I have seen throughout the years is larger engined cars 1970's with mid-range gearing was replaced with smaller engined ones 1980's with less efficient lower gearing. Then the 1990's came along and cars got heavier so the smaller engines where replaced with larger ones while keeping the same inefficient gearing. 3.0L V6's became 3.5L V6's and 4.0L V8's became 4.5L's and then in the early 2000's cars got heavier still all the while keeping the same low and inefficient gearing. Only rarely has someone built a mid to large torquey engined car with high gearing allowing the engine to turn slower and in turn be more efficient. The Chevrolet Caprice was one example that had great fuel economy for its size in the real world. Replacing todays DOHC 3.6L V6 in the Cadillac CTS with a slower turning OHV 4.5L-or-4.7L V6 with higher gearing to deliver like performance would be more efficient. The Domestic makes have been to Euro/Asian in there thinking with DOHC and lower gearing and in turn actually lost our efficiency advantage over all. In Asia and Europe they built smaller engines due to tax reasons among others so a lower gearing was needed to make up for the lack of Torque from those smaller engines. DOHC and 4VPC was used again to make up for the engines smaller size and that allowed for higher revving with the lower gearing a prefect match. In our attempting to be like them with our traditionally larger models we have lost what could have been a real world advantage in fuel economy.

[loki]

engines got a ton better in the 90's compared to 80s... mainly from a compression ratio stand point (and emissions)

the larger engines were also attributable to gas prices some.

wasn't the NEON the last car to be using a 3speed auto (that was actually a 4+ cyl)? and that was 2nd gen too (2000-2005) [according to wiki]

some of it was cost cutting, some of it was sticking with proven drive-trains...

[Mike The Canadian]

I think one point that most people are missing is this...

• An engine's breathing ability has very little, if anything, to do with fuel economy!
  

Sounds counter intuitive? Not really.

Let's look at it this way. Picture yourself moving a plunger inside a syringe. An engine's cylinder is similar. The small hole on top of the syringe causes resistance as you try to pump air in and out with the plunger. If you cut off the top of the syringe such that it is essentially an open ended cylinder, you'll have perfect volumetric efficiency -- perfect breathing with no restrictions -- and the only resistance comes from the friction between the plunger and the walls. Now picture a DOHC 4-valve engine as one with a bigger hole on top and a push rod 2-valve engine as one with a smaller hole. Naturally, as you work the plunger the syringe with a bigger hole has less resistance. In an engine this translate to lower pumping losses, more air being aspirated and more power! However, this is under wide open throttle conditions!

Now... picture attaching a rubber tube to both syringes and pinching the tube to constrict flow. That is exactly what the throttle plate does at all driving conditions except when you are flooring it. Therefore, at cruise and under moderate driving conditions, any intake restriction not present in the intake and through the valves is intentionally introduced by the throttle body! If your car doesn't do this, it needs to be recalled for a "stuck accelerator pedal". Therefor intake side restrictions of any engine typically does not introduce additional pumping losses at cruise and does not impact fuel economy.

Now, we are talking about intake restictions of course. On the exhasut side there is no throttle plate. However, exhaust under pressure self-aspirate quite easily even through one valve or valves with less opening. And, exhaust restrictions, while ever present typically does not impact power or economy until reasonably high up in the rev range (4000~5000 rpm or so). At cruise and under moderate driving conditions the impact is minimal.

Yup! You seem to know your stuff man, I'm very impressed and happy that your on here. A lot of people like to talk out of their asses. I don't claim to be an expert myself, everything I know is due to driving and the Internal Combustion Engines course I took as a part of 3rd year engineering last semester. Very good course and a great eye opener! So much to think about now, and there are practically a million type of efficiencies. To be hounest any calcs we did were really no where near realistic. We did a project on looking at the compression ratio's for NA and supercharged engines along with their power and efficiency differences. Me being me, I chose the 3800 and I ended up getting that it produces 280 hp NA, however after arbitrarily selecting a mechanical efficiency (looking at other examples and what was common) I got closer to the value, but it was still quite a bit off, more specifically the torque was far off. Same went for the supercharged one, but you certainly learn a lot. I found it especially interesting to look at things such as volumetric efficiency on a chart based on rpm and how runner lengths are generally only very efficient for one rpm range. Although this is talking mostly older engines, it's very interesting stuff.

I have a curious question, what is the combustion efficiency effected by mainly? Is it simply the octane of gasoline and spark plug? Do engine configurations (IBC, DOHC etc) make a difference?

[dwightlooi]

Yup! You seem to know your stuff man, I'm very impressed and happy that your on here. A lot of people like to talk out of their asses. I don't claim to be an expert myself, everything I know is due to driving and the Internal Combustion Engines course I took as a part of 3rd year engineering last semester. Very good course and a great eye opener! So much to think about now, and there are practically a million type of efficiencies. To be hounest any calcs we did were really no where near realistic. We did a project on looking at the compression ratio's for NA and supercharged engines along with their power and efficiency differences. Me being me, I chose the 3800 and I ended up getting that it produces 280 hp NA, however after arbitrarily selecting a mechanical efficiency (looking at other examples and what was common) I got closer to the value, but it was still quite a bit off, more specifically the torque was far off. Same went for the supercharged one, but you certainly learn a lot. I found it especially interesting to look at things such as volumetric efficiency on a chart based on rpm and how runner lengths are generally only very efficient for one rpm range. Although this is talking mostly older engines, it's very interesting stuff.

I have a curious question, what is the combustion efficiency effected by mainly? Is it simply the octane of gasoline and spark plug? Do engine configurations (IBC, DOHC etc) make a difference?

Combustion efficiency is affected mainly by:-

• Compression Ratio*
  
• How homogeneous (well mixed) the charge is
  
• Fuel-air-ratio
  
• Time**
  

* Actually it's more like cylinder pressure. Although static compression has a lot to do with it, supercharging or leaving the intake valves open well into the compression stroke (Atkinson/Miller cycle) can also affect the effective cylinder pressures (effective compression).

** Gasoline in air burns at the same rate regardless of speed at which the engine operates. In fact, the flame front from the spark travels at less than the speed of sound unless the engine is detonating (knocking/pinging). Higher operating speed, less time before the exhaust valves open.

Pretty much that's it. The spark only matters if it is not powerful enough to consistently ignite the charge. Once you have a flame front propagating through the cylinder it doesn't really matter how intense the spark is. Similarly, Octane also does not matter at all except in allowing you to operate at higher compression ratios (or run more boost) without knocking. Knocking is when the combination of pressure and heat causes the mixture to spontaneously ignite. This causes a shock front that can be damaging to engines. There is also a difference between spontaneous conflagration and spontaneous detonation, one's nastier than the other, but that's a separate discussion for another time. If controlled and expected this can be harness to improve combustion efficiency -- in diesel engines or HCCI engines for instance. If uncontrolled it can hurt your engine. Octane doesn't make power, compression does. Without increasing compression (or boost), using higher octane fuel is a waste of your money.

[Mike The Canadian]

Combustion efficiency is affected mainly by:-

• Compression Ratio*
  
• How homogeneous (well mixed) the charge is
  
• Fuel-air-ratio
  
• Time**
  

* Actually it's more like cylinder pressure. Although static compression has a lot to do with it, supercharging or leaving the intake valves open well into the compression stroke (Atkinson/Miller cycle) can also affect the effective cylinder pressures (effective compression).

** Gasoline in air burns at the same rate regardless of speed at which the engine operates. In fact, the flame front from the spark travels at less than the speed of sound unless the engine is detonating (knocking/pinging). Higher operating speed, less time before the exhaust valves open.

Pretty much that's it. The spark only matters if it is not powerful enough to consistently ignite the charge. Once you have a flame front propagating through the cylinder it doesn't really matter how intense the spark is. Similarly, Octane also does not matter at all except in allowing you to operate at higher compression ratios (or run more boost) without knocking. Knocking is when the combination of pressure and heat causes the mixture to spontaneously ignite. This causes a shock front that can be damaging to engines. There is also a difference between spontaneous conflagration and spontaneous detonation, one's nastier than the other, but that's a separate discussion for another time. If controlled and expected this can be harness to improve combustion efficiency -- in diesel engines or HCCI engines for instance. If uncontrolled it can hurt your engine. Octane doesn't make power, compression does. Without increasing compression (or boost), using higher octane fuel is a waste of your money.

Thanks for the quick and informative response! In class it was assumed to be 100% almost all of the time. I'm also curious as to why DI provides more power and better fuel economy. Just thinking about it I know the charge is normally introduced before or in the intake manifold where it mixes with the incoming air. This doesn't always work great and it's more of a prediction on how much fuel to dump correct? I can see that direct injection has the positive aspect that fuel is directly injected into the combustion chamber and exact/proper amounts can always be calculated versus dumping a bunch into the incoming air stream. I can see this increasing fuel economy. However doesn't the gasoline being delivered into the oncoming intake air stream also cause cooling of the air which in turn increases your volumetric efficiency? (Cold air, density changes, you get more expansion etc..) Does DI have the same effect? I'm 90% sure there is something I'm missing here but it's always intrigued me. DI has also been used on diesel for a long time has it not?

Thanks again for allowing me to pick your brain lol.

Sorry if I've steered this thread off-topic, I'll keep any further off topic discussion to PM's or related threads.

[smk4565]

The only reason GM has kept using the pushrods is development cost, they are too broke to make a new engine, so they have to keep bringing the old one along, much like they did with the 3800 V6 for 20 years. For 20 years they kept claiming how it could match the smaller Japanese DOHC V6s in power and economy, but at the end of the day, the DOHC V6s left the 3800 in the dust. Same will happen with V8s.

BMW, Mercedes, Aston Martin, Ferrari, Audi, Jaguar, Lexus, and Infiniti aren't all wrong. The only ones that think the pushrod V8 is still viable are Chrysler and GM, the two companies that have lost the most market share in the past 20 years and the only 2 that filed for bankruptcy. And I don't mean to say the engine is why they filed bankruptcy, but both Chrysler and GM had a long stretch where they chose not to innovate, and just try to milk every last dime out of old products or technology.

[Robert Hall]

The only reason GM has kept using the pushrods is development cost, they are too broke to make a new engine, so they have to keep bringing the old one along, much like they did with the 3800 V6 for 20 years. For 20 years they kept claiming how it could match the smaller Japanese DOHC V6s in power and economy, but at the end of the day, the DOHC V6s left the 3800 in the dust. Same will happen with V8s.

BMW, Mercedes, Aston Martin, Ferrari, Audi, Jaguar, Lexus, and Infiniti aren't all wrong. The only ones that think the pushrod V8 is still viable are Chrysler and GM, the two companies that have lost the most market share in the past 20 years and the only 2 that filed for bankruptcy. And I don't mean to say the engine is why they filed bankruptcy, but both Chrysler and GM had a long stretch where they chose not to innovate, and just try to milk every last dime out of old products or technology.

Also, part of why both GM and Chrysler have clung to pushrod V8s is because V8 usage in their cars is tied to their needs of their trucks. Interestingly, Ford hasn't had this problem..they evolved and went to OHC V8s years ago for cars and trucks.

Not to say there is anything necessarily wrong w/ GM or Chrysler's V8s, but the competition (at least in the luxury and sports car markets) clearly long ago moved to OHC V8s..

Edited July 8, 2010 by Cubical-aka-Moltar

[balthazar]

Combustion efficiency is affected mainly by:-

• Compression Ratio*
  
• How homogeneous (well mixed) the charge is
  
• Fuel-air-ratio
  
• Time**
  

These are the science of combustion efficiency...., is the inclusion of physicalities out-of-place?

For example, wouldn't it be legit to include combustion chamber design as a very real factor in efficiency? Partial vs/ fully machined, shape, plug orientation- are not these all factors... or is this broadening the discussion too much ?

[dwightlooi]

Thanks for the quick and informative response! In class it was assumed to be 100% almost all of the time. I'm also curious as to why DI provides more power and better fuel economy. Just thinking about it I know the charge is normally introduced before or in the intake manifold where it mixes with the incoming air. This doesn't always work great and it's more of a prediction on how much fuel to dump correct? I can see that direct injection has the positive aspect that fuel is directly injected into the combustion chamber and exact/proper amounts can always be calculated versus dumping a bunch into the incoming air stream. I can see this increasing fuel economy. However doesn't the gasoline being delivered into the oncoming intake air stream also cause cooling of the air which in turn increases your volumetric efficiency? (Cold air, density changes, you get more expansion etc..) Does DI have the same effect? I'm 90% sure there is something I'm missing here but it's always intrigued me. DI has also been used on diesel for a long time has it not?

Thanks again for allowing me to pick your brain lol.

Sorry if I've steered this thread off-topic, I'll keep any further off topic discussion to PM's or related threads.

Well, I was listing the list of conditions that for the most parts determine combustion efficiency (completeness of burning). This only depends on how close the air and fuel molecues are together (cylinder pressure/effective compression), how evenly they are mingling (homogeneity), in what proportions (mixture) and how much time there is to actually do the burning (time). Ideally you'll want extremely high compression, perfect mixing, ideal fuel-oxidizer ratio and an infinite amount of time. How you get there is a different matter.

DI improves combustion efficiency primarily basically because it allows increases compression. Because fuel is injected directly into the cylinder it can be injected even after the intake valves have closed. Late injection prevents knocking and detonation throughout much of the intake and compression cycle because air cannot detonate in the absence of fuel, period. The atomizing of fuel also reduces temperatures but this is minor compared to not having fuel in the cylinder when you don;t want it there. With DI the fuel is injected directly into the cylinder instead of behind the intake valves (or in the case of ancient throttle body injection or carburetion further upstream. This permits more accurate metering of fuel and the high pressure of injection creates a more evenly atomized fuel mist. Again, these effects are minor.

The end result is that DI engines can typically operate with 1 to 1.5 points higher compression than an otherwise equivalent port injected engine. GM's DI engines run 11.3 ~ 11.7:1 compression on regular 87 octane. With port injection they would be in the 9.8:1 ~ 10.3:1 bracket. This increase in compression is worth about 6~8% in power and torque by itself.

[dwightlooi]

These are the science of combustion efficiency...., is the inclusion of physicalities out-of-place?

For example, wouldn't it be legit to include combustion chamber design as a very real factor in efficiency? Partial vs/ fully machined, shape, plug orientation- are not these all factors... or is this broadening the discussion too much ?

As I said, the physical conditions and nothing else determine combustion efficiency. Engineering details help create those conditions, but it is the conditions themselves that govern the burning.

But, yes, combustion chamber design matters a lot. The squish decks help with mixing and compaction. Shapes that avoid localized hot spots resist detonation. A centrally located spark minimizes the flame frront distance from spark to edge of chamber. In the end these mostly allow higher compression ratios and/or are conducive to a homogeneous charge.

[CanadianBacon94]

The only reason GM has kept using the pushrods is development cost, they are too broke to make a new engine, so they have to keep bringing the old one along, much like they did with the 3800 V6 for 20 years. For 20 years they kept claiming how it could match the smaller Japanese DOHC V6s in power and economy, but at the end of the day, the DOHC V6s left the 3800 in the dust. Same will happen with V8s.

BMW, Mercedes, Aston Martin, Ferrari, Audi, Jaguar, Lexus, and Infiniti aren't all wrong. The only ones that think the pushrod V8 is still viable are Chrysler and GM, the two companies that have lost the most market share in the past 20 years and the only 2 that filed for bankruptcy. And I don't mean to say the engine is why they filed bankruptcy, but both Chrysler and GM had a long stretch where they chose not to innovate, and just try to milk every last dime out of old products or technology.

THE 3800 WAS AN OLD ENGINE, it does not represent the IBC engine configuration, instead it represents an engine left in cars for too long. An engines configuration doesnt change the fact that if it is produced with minimal change for too long it will become behind the times. (NorthStar is yourexample )

[CanadianBacon94]

Actually, the original "Passenger Car" table has three columns. There was originally a V8 just for Caddy exclusively. This has a traditional cross plane crank, dual VVT, DI, Cylinder De-activation and a BALANCE SHAFT under the high mounted camshaft to damp out residual end to end vibration on cross plane V8s. This is the "Serene V8" and it should make about 430~450 hp. Vette and Camaro SSes were supposed to get a more ranchous V8 making 480 hp NA. This has cylinder de-activation deleted and uses a flat plane crank with no balancer! I decided that it is one too many engine and a compromised "universal 6.2" may be a better idea.

ive heard that a flat plane crank would change the engine note to more of a whiny high pitch, high rev sound, does this affect the tone by itself?

Edited July 9, 2010 by CanadianBacon94

[Drew Dowdell]

The only reason GM has kept using the pushrods is development cost, they are too broke to make a new engine, so they have to keep bringing the old one along, much like they did with the 3800 V6 for 20 years. For 20 years they kept claiming how it could match the smaller Japanese DOHC V6s in power and economy, but at the end of the day, the DOHC V6s left the 3800 in the dust. Same will happen with V8s.

BMW, Mercedes, Aston Martin, Ferrari, Audi, Jaguar, Lexus, and Infiniti aren't all wrong. The only ones that think the pushrod V8 is still viable are Chrysler and GM, the two companies that have lost the most market share in the past 20 years and the only 2 that filed for bankruptcy. And I don't mean to say the engine is why they filed bankruptcy, but both Chrysler and GM had a long stretch where they chose not to innovate, and just try to milk every last dime out of old products or technology.

Except that since at least 1991, GM hasn't been without a DOHC V6 available in at least one car... and the current pushrod 3.5 and 3.9 were new engines when released and in no way related to the 3800. But you've been told this before and you continue to peddle your BS

[dwightlooi]

ive heard that a flat plane crank would change the engine note to more of a whiny high pitch, high rev sound, does this affect the tone by itself?

Well, no. Not really.

A flat plane crank sounds like two inline-4s. It is not a well balanced design and vibrates at about 1.4 times the magitude of a 4-potter of half its displacement. This is partly why Ferrari V8s (which are almost always flatplane) are also typically quite small in displacement and have short strokes. A 4.3 liter V8 will vibrate 1.4 times worse than a 2.15 liter Inline four, whereas 6.0 flat plane V8 will shake as 1.4 times worse than a 3.0 Inline 4. The orientation of the crank has nothing to do with whines; whines usually comes from the accessory drive or, in some cars, the belt drive for camshaft(s) or supercharger.

A flat crank however will not have the slightly off-beat V8 sound typically associated with muscle cars -- that comes from the fact that cross plane V8s do not fire cylinders alternatively from each bank. Instead, the fire a bank twice every other set -- LRLLRLRR. This causes the exhaust imbalance which unless you have a cross over pipe or H-pipe linking the exhaust streams from both sides you'll end up with that off-beat "di-da-duh-duh-di-da-duh-duh" exhaust note.

Racing V8s are often flat plane because their balanced exhaust pulses are better for maximizing output without complex, bulky and heavy exhaust plumbing. Most contemporary European, Japanese or American "production car" V8s are cross plane. The notable exceptions that are flat plane being all the Ferrari V8s and, believe it or not, the 4.0 liter W8 engine in the Volkswagen Passat and Phaeton.

Edited July 10, 2010 by dwightlooi

[CanadianBacon94]

""I don’t like the rumble of a typical V-8,” explains Ruf. “This engine has a more nervous sound like a racing engine.” That’s because the Ruf V-8 uses a 180-degree flat-plane crankshaft design, like that of the Ferrari V-8 and many racing engines."

~C&D(BMW Monthly)

^^^this was what i was talking about

[dwightlooi]

""I don’t like the rumble of a typical V-8,” explains Ruf. “This engine has a more nervous sound like a racing engine.” That’s because the Ruf V-8 uses a 180-degree flat-plane crankshaft design, like that of the Ferrari V-8 and many racing engines."

~C&D(BMW Monthly)

^^^this was what i was talking about

Well, how one characterize a sound as "nervous" is highly subjective. The difference between a flatplane and crossplane V8 can be summarized as follows:-

Cross Plane:

+ Good Balance, low vibrations (~50% the level of 4-cylinder engine with half the capacity)

- Uneven Exhaust Pulses (LRLLRLRR), slower reving (heavy crankshaft), higher center of gravity (large crank case w/big counter weights)

Flat Plane:

+ Even Exhaust Pulses (LRLRLRLR), fast reving (lightweight crankshaft), low center of gravity (slim crank case w/tiny counter weights)

- Poor Balance, high vibrations (~140% the level of a 4-cylinder engine with half the capacity)

[balthazar]

If I understand cranks correctly here :: Center of gravity should be the same- the journals are only offset around the same centerline- they are not (necc.) larger in radius in a cross-plane design.

Likewise, weight will not (necc.) be any greater, as again- journals are shifted around a centerline, not (necc. larger). This is first & foremost a vibration control issue via balance, not size/weight (tho that CAN come into play also).

[dwightlooi]

If I understand cranks correctly here :: Center of gravity should be the same- the journals are only offset around the same centerline- they are not (necc.) larger in radius in a cross-plane design.

Likewise, weight will not (necc.) be any greater, as again- journals are shifted around a centerline, not (necc. larger). This is first & foremost a vibration control issue via balance, not size/weight (tho that CAN come into play also).

The journals themselves are centered around the same axis. However, cross plane designs have heavier & bigger counter weights. Cross plane designs carry enough counter weights to balance the crank journal, rod and pistons. Flat plane ones balances the journal and the part of the rod only. The cross plane V8 is the only mainstream engine configuration that does this. Normally engines do not carry this much counter weights because while they can cancel most of the up-down vibrations from the pistons, counter weights also introduce side to side shake. Only in the cross plane V8 does the piston from the opposite bank neatly cancel the side to side moments of the counter weight. This makes cross planes very well balanced, but also rather slow revving.

Most of the time, the diameter of the counter weights on the cross plane V8 are slightly larger than the diameter on the journal ends where the rods go. As a consequence, the crank case needs to be a bit bigger and the oil pan a bit taller. The crankshaft itself is also heavier, meaning the engine is heavier, although this is rather inconsequential unless you are trying to shave off the very last 5 pounds.

[67impss]

The only reason GM has kept using the pushrods is development cost, they are too broke to make a new engine, so they have to keep bringing the old one along, much like they did with the 3800 V6 for 20 years. For 20 years they kept claiming how it could match the smaller Japanese DOHC V6s in power and economy, but at the end of the day, the DOHC V6s left the 3800 in the dust. Same will happen with V8s.

BMW, Mercedes, Aston Martin, Ferrari, Audi, Jaguar, Lexus, and Infiniti aren't all wrong. The only ones that think the pushrod V8 is still viable are Chrysler and GM, the two companies that have lost the most market share in the past 20 years and the only 2 that filed for bankruptcy. And I don't mean to say the engine is why they filed bankruptcy, but both Chrysler and GM had a long stretch where they chose not to innovate, and just try to milk every last dime out of old products or technology.

SMK you need to take 5min to educate yourself so you don't sound so full of bull that you lack all sense of credibility. Afew of the others could use this small primer also. The 3800 was not an old engine as you will read it was a constantly changing engine. The series II was a completely new design block on up.

The following is attributed to Wikipedia while it might not be perfect it will get the job done.

"198cid odd-fire

1961-1963

The first engine in this family was introduced in 1961 for the 1962 model year Buick Special with Buick's 198 cu in (3.2 L) engine, the first V6 in an American car.

225cid odd-fire

1964-1967

This engine was used in Buick's intermediate-sized Special and Skylark models from 1964 to 1967 and Oldsmobile's mid-sized F-85/Cutlass models for 1964 and 1965.

225cid odd-fire

1965-1971

In 1965, Kaiser-Jeep began using the Buick 225 in Jeep CJs.

231cid odd-fire

1975-1976

GM made an offer to buy back the tooling and manufacturing line from AMC in April, 1974, and began building the engines on August 12[1]. With production back within GM, Buick re-introduced the V6 that fall in certain 1975 models.

The bore was enlarged to 3.8 in (96.5 mm), identical to the Buick 350 and Olds 307 V8s, yielding 231 cu in (3.8 L) displacement.

231cid Even-Fire

1977-1979

Buick devised an innovative "split-pin crankshaft" redesign of the crankshaft, flywheel, and distributor which greatly alleviated the problem, creating a new even-firing version of the engine.

3.8L Even-Fire

1978-1979

Larger valves and better intake and exhaust boosted the power output for 1979.

Turbo 3.8L Even-Fire

1978-1989

A turbocharged version was introduced as the pace car at the 1976 Indianapolis 500, and a production turbo arrived in 1978. The turbo 3.8 received sequential fuel injection and distributorless ignition in 1984. In 1986 an air-to-air Garrett intercooler was added and the RPO Code became LC2. The LC2 engine has a bore of 3.80" and a stroke of 3.40". The respective horsepower ratings for 1986 & 1987 were 235 hp (175 kW) & 245 hp (183 kW). The limited production GNX benefitted from additional factory modifications such as a ceramic turbocharger, more efficient Garrett intercooler, low restriction exhaust system and revised programming which resulted in a 276 hp (206 kW) factory rating although it is widely known that the actual power was closer to 300 hp (222 kW).

3.2L

1978-1979

A smaller version of this engine was produced in 1978 and 1979 for the Century and Regal and Chevrolet Monza. The bore was reduced to 3.5 in (89 mm), resulting in an engine of 196 cu in (3.2 L) piston displacement. The RPO code was LC9. Initially this engine produced 90 horsepower (67 kW), but in 1979 it received the same improvements in the cylinder heads as did the LD5, and therefore power increased to 105 horsepower (78 kW).

4.1

1980-1984

In response to rising gas prices, a larger 252 cu in (4.1 L) version of the 3.8 L LD5 V6 was produced from 1980 through 1984 and marketed as an alternative to a V8. The bore was enlarged to 3.965 in (100.71 mm), yielding an output of 125 horsepower (93 kW) and 205 lb·ft (278 N·m). This engine was used in many large rear-wheel drive Buicks, and in some models from each of GM's other divisions, including Cadillac which offered the "big" Buick V6 in several models from 1980 to 1984 as a no-cost option to the troublesome V8-6-4 engine used in 1981 and early versions of the aluminum-block Cadillac HT-4100 V8 introduced in 1982. It was also the standard powerplant in the front-drive Riviera and Olds Toronado from 1981 to 1984. Additionally, the 4.1 block was used unsuccessfully at Indianapolis for racing. Its only weakness was the intake valve pushrod seals.

3.0

1982-1988

A small 3.0 L (181 in³) version of the Buick V6 was produced for GM's 1980s front-wheel drive cars. Introduced in 1982, it was a lower deck version of the 3.8 designed for transverse application in the new GM A platform cars such as the Buick Century and Oldsmobile Cutlass Ciera. It shared the same bore size as its larger sibling, but featured a smaller stroke of 2.66 in (67.56 mm). Introduced with a Rochester E2ME 2-bbl carburetor, it later received multipoint fuel injection.

3800 Pre-Series I

1989-199

LN3 Naturally Aspirated

An LN3 installed in a 1989 Pontiac Bonneville. This engine produced 165 hp (123 kW) and 220 lb·ft (298 N·m) of torque.

The 3.8 L (3800 cc) LN3 was an engine produced by General Motors' Buick Division. Introduced in 1988 the 3800 LN3, would later be loosely considered the Pre-Series I, although the older 3.8 SFI (LG3) was still available that year in some models. Designated initially by VIN code C, the multiport fuel injected 3800 LN3 was a major redesign, featuring changes such as a balance shaft, on-center bore spacing, use of a 3x/18x crank-trigger system, and other improvements. This generation continued in use in several GM products into the 1990s. It produced 165 hp (123 kW) and 220 lb·ft (298 N·m).

The LN3 is very closely related to the Series I L27 and Series I L67 Supercharged. In fact, supercharger-related hardware can be fitted to an LN3 without changing the cylinder heads (ECM reprogramming required). The L27 has a two piece, upper plenum intake and lower intake, the LN3 is all one piece.

3300

1989-

A smaller 3.3 L 3300 was introduced in 1989 and produced through 1993. It is effectively a lower-deck version of the 3800, with a smaller 3.7 in (93.98 mm) bore and 3.16 in (80.26 mm) stroke for 3,344 cc (204.1 cu in). Like the 3800, it used a cast iron block and heads, push rods, and hydraulic lifters. Unlike the 3800, however, it used a batch-fire injection system rather than sequential injection, as evidenced by the lack of a cam position sensor. It also did not have a balance shaft. Power output was 160 hp (120 kW) at 5200 rpm and 185 lb·ft (251 N·m) at 2000 rpm with a 5500 rpm redline.

Series I

1992-1994

L27 Naturally Aspirated

A 3800 Series I L27 Naturally Aspirated engine installed transversely in a 1995 Buick Regal.

The LN3 was replaced by the 3,791 cc (3.791 L; 231.3 cu in) L27 in 1991-1992 and produced 170 horsepower (130 kW) from 1992 onward, this engine was referred to as the Series I 3800. In Australia, the LN3 was also replaced by the L27 by Holden who used the engine in their series 2 (1991) VN Commodore range. However, the Australian L27 retained the LN3's one piece upper intake and lower plenum. Power was still boosted to 127 kW (170 hp) for the Holden L27, before being boosted to 130 kW (177 PS; 174 hp) in the revised VR Commodore in 1993. The L36 made its debut in 1995.

L67 Supercharged

1991-1995

The Series I Supercharged engine went through many internal changes and the horsepower changed rapidly between the time it was introduced and the time that the Series II L67 was introduced. The M62 supercharger was manufactured by Eaton, exclusively for the GM 3800 engine. HP was rated at 205 for 1991-1993 engines (models vary), and 225 for 1994-1995 engines. The additional horsepower and strength was gained by using six bolt main bearing caps, a roller camshaft, semi forged bottom end, larger throttle body, roller rockers and epoxy coated supercharger rotors, improving efficiency. The 1994-1995 utilized a 2.85-inch (72.4 mm) pulley versus the 2.55-inch (64.8 mm) pulley used on the 91-93 supercharger.

Series II

1995-

Introduced in 1995, the Series II is quite a different engine. Although the stroke for the 3.8 L engine remained at 3.4 in (86 mm), and the bore remained at 3.8 in (97 mm), the engine architecture was vastly changed. The deck height is shorter than the Series I, reducing weight and total engine package size. This required that the piston connecting rods be shortened 1 in (25 mm), and the crankshaft was also redesigned. A new intake manifold improved breathing while a redesigned cylinder head featured larger valves and a higher compression ratio. The result was 205 hp (153 kW) and 230 lb·ft (312 N·m), better fuel economy, and 26 lb (12 kg) lighter overall weight (to 392 lb (178 kg)). The 3800 weighs only 22 lb (10.0 kg) more than the High Feature V6, despite being an all cast iron design.

The new intake manifold greatly improved airflow. To meet emissions standards, an EGR tube was placed in the intake manifold to reduce combustion temperatures. This increases fuel mileage by a substantial margin.

The 3800 Series II was on the Ward's 10 Best Engines list for 1995 through 1997.

L67 Supercharged

1996-2005

The L67 is the supercharged version of the Series II L36 and appeared in 1996, one year after the normally-aspirated version. It uses the Eaton Generation III M90 supercharger with a 3.8" pulley, a different throttle body, fuel injectors, cylinder heads, and lower intake manifold than the L36 uses. Both engines share the same engine blocks, but compression is reduced from 9.4:1 in the L36 to 8.5:1 for the L67. Power is up to 240 hp (180 kW) and 280 lb·ft (380 N·m) of torque. Final drive ratios are reduced in most applications, for better fuel economy and more use of the engine's torque in the low range. The engine was built in Flint, Michigan. The engine was certified LEV in 2001.

Series III

2004-2009

The Series III motors include many changes. The upper intake manifold is now aluminum on the naturally aspirated models. Intake ports are mildy improved, 1.83" intake valves (instead of 1.80" as on Series II) and 1.52" exhaust valves were introduced in 2003 engines, just before switching to Series III. Electronic throttle control is added to all versions, as is returnless fuel injection. Stronger powdered metal sinter forged connecting rods are used in 2004+ supercharged, and 2005+ naturally aspirated engines, instead of the cast iron style from Series II engines. Emissions are also reduced. In 2005, it was the first gasoline engine in the industry to attain SULEV (Super Ultra Low Emissions Vehicle).

Also note that Series III engines are the base for any 3800 produced for the 2004 year and up. This means the same block, heads, & connecting rods apply to any remaining Series II engines made after 2004 also. The difference is that Series III engines received the new superchargers (Generation 5 - Eaton m90 - if equipped), intake manifolds, fuel systems, and electronics.

L26 Naturally Aspirated

2004-2009

The L26 is the Series III version of the 3800. It is still a 3.8 L (231 cu in) design. Compression remains at 9.4:1 as with previous L36's, but the aluminum upper intake (2004+) and stronger connecting rods (2005+) are the primary physical changes. The powdered metal connecting rods were meant to be introduced in 2004 along with the L32's, but the GM plant in Bay City, Michigan that supplies the Flint, Michigan plant could not achieve the desired production dates in time for that engine year.

L32 Supercharged

2004-

The L32 is a supercharged Series III. Introduced in 2004, the main differences between the L67 and the L32 is the L32's electronic throttle control, slightly improved cylinder head design, and updated Eaton supercharger, the Generation 5 M90. Power output is up to 260 HP (194 kW) in the Grand Prix GTP.

Discontinuation

Production of the 3800 V6 engine officially ended on Friday, August 22, 2008 when plant 36 was closed. There was a closing ceremony and speakers who extolled the virtues of the engine. Originally GM had set this date for January 1, 1999; however, due to the vast number of complaints from both investors and customers because of the popularity and reliability of the engine, the date was extended. At the end of production, the LZ4 3500 OHV V6 replaced the naturally aspirated 3800 applications, and the LY7 3600 DOHC V6 replaced the supercharged 3800 applications"

As you can see at no time was there a 20 year period of stagnation.

[aldw]

Seeing the latest comparo between Mustang and Camaro on Road and Track covering the GM and Ford V-8s, they do list the benefits and drawbacks of both, but it also helps clarify why the DOHC engine would be preferable over the pushrod regardless of issues such as head width or parts complexity, especially for the consumer. That's also why reviving the Ultra V-8 would better for Caddy than the Gen 5.

[Drew Dowdell]

I thought one of the features of this new 5.5 was that it was designed to be set up as either pushrod or DOHC?

[dwightlooi]

Seeing the latest comparo between Mustang and Camaro on Road and Track covering the GM and Ford V-8s, they do list the benefits and drawbacks of both, but it also helps clarify why the DOHC engine would be preferable over the pushrod regardless of issues such as head width or parts complexity, especially for the consumer. That's also why reviving the Ultra V-8 would better for Caddy than the Gen 5.

How so?

BTW, I read the article. And one thing they didn't talk about is the higher friction in the DOHC valvetrain because of its complexity and the number of bearing surfaces.

Camlobes Cam-Bearings Valve-stems Rocker-interfaces Sprockets

Pushrod 16 5 16 16 1

DOHC 32 20 32 32 4

More frictional elements, more friction, less fuel economy. But you get specific output in return. The problem is that is the additional 17% in specific output (82bhp/L vs 70bhp/L) worth the weight, bulk and higher friction of the DOHC powerplant?

The Mustang's advantage wasn't in the engine really, it was that it was a significantly lighter car (live axle or not).

Edited July 16, 2010 by dwightlooi

[regfootball]

So GM must have inefficient engineering if their engine is lighter but the car itself is a lot heavier.

so there is no merit to the CIBOHVPR motor with 'lower friction' if in the end the car is a pork roast in comparison to the mustang, which gives you the DOHC and lower weight overall.

sounds to me like the GM engineers need to work a little harder.

If the general's engine is 5% lighter, I should expect the whole car can be optimized to be 5% lighter as well if you are using the pushrod motor and simplicity as your calling card.

How so?

BTW, I read the article. And one thing they didn't talk about is the higher friction in the DOHC valvetrain because of its complexity and the number of bearing surfaces.

Camlobes Cam-Bearings Valve-stems Rocker-interfaces Sprockets

Pushrod 16 5 16 16 1

DOHC 32 20 32 32 4

More frictional elements, more friction, less fuel economy. But you get specific output in return. The problem is that is the additional 17% in specific output (82bhp/L vs 70bhp/L) worth the weight, bulk and higher friction of the DOHC powerplant?

The Mustang's advantage wasn't in the engine really, it was that it was a significantly lighter car (live axle or not).

I thought one of the features of this new 5.5 was that it was designed to be set up as either pushrod or DOHC?

they tried that before...LOL TWIN DUAL CAM, yeah that was reliable....

Edited July 16, 2010 by regfootball

[Drew Dowdell]

So GM must have inefficient engineering if their engine is lighter but the car itself is a lot heavier.

so there is no merit to the CIBOHVPR motor with 'lower friction' if in the end the car is a pork roast in comparison to the mustang, which gives you the DOHC and lower weight overall.

sounds to me like the GM engineers need to work a little harder.

The Camaro came from a large sedan that was cut down. The Lincoln LS on which the Mustang is loosely based is much lighter.

they tried that before...LOL TWIN DUAL CAM, yeah that was reliable....

And it had nothing to do with being based on a pushrod block. It was only because GM half assed the timing belt idler pulleys using plastic ones that would split instead of steel, and they undersized the alternator and put it in a hot spot.

There was NOTHING wrong with that engine that wasn't easily correctable. Like all GM products of that era, once they got the engine right, they discontinued it. The 1995 Dual Twincams are pretty much fine.

[regfootball]

while its fine to try to excuse the camaro for being built on a heavy platform it just shows that it was not built for optimal performance.

we all know the camaro is a styling exercise, and that's ok. just don't make excuses for it when the mustang has better sporting behavior. And the Mustang can still be lighter with a DOHC engine.

[Drew Dowdell]

For now.

I haven't driven the Mustang yet, but I found the Camaro to be very livable as a daily driver.