Cadillac News: The Unclear Future of the Blackwing V8

[Robert Hall]

7 minutes ago, dfelt said:

 

If Cadillac CANNOT set themselves apart from the rest of GM with their EVs and using names again, then Cadillac will never be anything other than a small local specific luxo auto company that has given up on the world.

GM is rapidly becoming a small regional automaker, period...

[balthazar]

Inconsequential.

[riviera74]

I have noticed that the 8AT on the CT6 had some issues, whereas I have heard no issues at all with the 10AT on the CT6-V with the Blackwing V8. 

A: Is this all true and B: Why is that?

[frogger]

 

[Robert Hall]

16 hours ago, riviera74 said:

I have noticed that the 8AT on the CT6 had some issues, whereas I have heard no issues at all with the 10AT on the CT6-V with the Blackwing V8. 

A: Is this all true and B: Why is that?

Different transmissions.   There were two 8-speeds, one of which is involved in a class action lawsuit.   The 10 speed is a new transmission jointly developed w/ Ford.

Per the Wikipedia: The 8L90 is the subject of a class-action lawsuit filed in December 2018 that alleges the transmission suffers from persistent "shudder" issues and that GM has known about the problems since its introduction and has failed to provide a solution, instead choosing to wait until the unit is out of warranty.^[2]

Edited February 24, 2020 by Robert Hall

[ccap41]

5 minutes ago, Robert Hall said:

Different transmissions.   There were two 8-speeds, one of which is involved in a class action lawsuit.   The 10 speed is a new transmission jointly developed w/ Ford.

Per the Wikipedia: The 8L90 is the subject of a class-action lawsuit filed in December 2018 that alleges the transmission suffers from persistent "shudder" issues and that GM has known about the problems since its introduction and has failed to provide a solution, instead choosing to wait until the unit is out of warranty.^[2]

That actually sounds slightly worse than Ford and their piece of ish DCT. They "at least" extended the warranty coverage period.

[Robert Hall]

Sounds like Ford was the lead developer on the 10 speed...it's in wide use across Ford and GM, everything from pony cars to full size trucks and SUVs.  So competitors like the Mustang and Camaro, Navigator and Escalade are using variations of the same transmission.

https://en.wikipedia.org/wiki/Ford-GM_10-speed_automatic_transmission

Edited February 24, 2020 by Robert Hall

[riviera74]

58 minutes ago, Robert Hall said:

Different transmissions.   There were two 8-speeds, one of which is involved in a class action lawsuit.   The 10 speed is a new transmission jointly developed w/ Ford.

Per the Wikipedia: The 8L90 is the subject of a class-action lawsuit filed in December 2018 that alleges the transmission suffers from persistent "shudder" issues and that GM has known about the problems since its introduction and has failed to provide a solution, instead choosing to wait until the unit is out of warranty.^[2]

SAD.  Especially since GM could probably replace the 8L90 with the 8L45 and solve the lawsuit that way.

BTW, how do you know which 8AT is in the car/truck you are driving?

[Robert Hall]

It sounds like 8L45 replaced the 8L90, same transmission but the 45 was modified to be lighter.  Sounds like some models such as the CT6 used both. 

[USA-1]

The 8L45 is the 8 speed auto used in the V6 Colorado/Canyon and Camaro and was paired with the V6 CTS as well. The 8L90 was used in full-size trucks from 2015 -2019 Silverado to Escalade as well as CTS-V, C7 Vettes and Camaro SS/ZL1 and it's internals are designed to handle the increased torque of the 6.2L in all those applications. The shutter issue that people have had with the 8L90 is either A. The torque converter acting up and not locking up or locking up too soon, And/or B. The Eco fuel saving program in the transmission TCM that's designed to get the transmission in the highest gear possible, as soon as possible, which can also cause lagging or shuttering, add to that a faulty torque converter and you have a problem. So it was the torque converters and the Eco shift algorithm that plagued the 8L90. I drive my Silverado in town with it in Manual mode and select 4th or 5th as max top gear with the selector and it works great, no shuttering or lagging and in D on the freeway and I've had no problems and neither have family or friends that have the 8L90 in their trucks. 

Ford came to GM to "partner up" on the 10 speed knowing that GM knows automatic transmissions very well and knows how to build solid ones THM400 Hydra-matic comes to mind. Ford's AT's have notoriously been CRAP from F150 to F350 to the Econoline vans for decades, I know because I've had both GM and Ford trucks in my commercial business. Interesting fact that GM's 10 speed 10L80 transmission has been great and problem free in the Camaro SS/ZL1 and Silverado/Sierra, Tahoe/Yukon/Escalade, but Ford's 10 speed 10R80 of the "same mold" has had major internal issues in the F150 and Mustang. So it's all about how it's put together by each manufacturer and which one knows how to do so correctly. Makes you wonder if GM engineers saw the flaws that Ford had with their design and went back, fixed it for their vehicles and didn't tell Ford that it was fcked up. Ford now has their hands full with Class Action lawsuits with their problematic 10 speed.

https://www.classaction.org/blog/defective-10-speed-ford-f-150-transmissions-shift-harshly-and-erratically-class-action-claims

https://www.stangnet.com/mustang-forums/threads/2018-mustang-10-speed-failure.903142/

https://fordauthority.com/2019/08/ford-f-150-10-speed-transmission-subject-new-lawsuit/

 

Edited February 25, 2020 by USA-1

[ocnblu]

When my truck is cold, on the first 2-3 shift, it hangs up/goes into neutral for a second then hard shifts into third.  Actually throws my head forward then back when it does this.

[USA-1]

16 hours ago, ocnblu said:

When my truck is cold, on the first 2-3 shift, it hangs up/goes into neutral for a second then hard shifts into third.  Actually throws my head forward then back when it does this.

Have you taken it in?! Not normal man. Do you have the V6 8A or I4 gas, Baby DMax with 6A?

My 2017 Colorado V6 8L45 I had was fine. Only thing I didn't like was the delay from 2-1 coming up to a stop it would get a little hung up in between so had a slight hiccup when back on throttle. Seemed like it was an issue in the valve body, but told it was normal by the Stealership of course. All gears smooth cruising or WOT other than that.  

[ocnblu]

8 hours ago, USA-1 said:

Have you taken it in?! Not normal man. Do you have the V6 8A or I4 gas, Baby DMax with 6A?

My 2017 Colorado V6 8L45 I had was fine. Only thing I didn't like was the delay from 2-1 coming up to a stop it would get a little hung up in between so had a slight hiccup when back on throttle. Seemed like it was an issue in the valve body, but told it was normal by the Stealership of course. All gears smooth cruising or WOT other than that.  

Nah, I haven't taken it in.  Weird that it does not do it each and every first cold 2-3 shift, just a high percentage of the time.  I have the 3.6 8A.

[dwightlooi]

Let me just say this... the Blackwing V8 is probably dead given that the new 2020 Escalade DID NOT USE IT.

And, good riddance. GM should focus on their strengths not try to copy the Europeans overly complicated and unrelaible engineering paradigms when it is 20 years too late and buyers committed to European engineering hype are not going to give Cadillac a second look anyway.

Here's what I believe GM should do for the 2020s... say hi to the....

Microblock Family

The Microblock is a pushrod 2-valve per cylinder architecture scaled down from the Smallblock design. Bore spacing is reduced from 111.76 mm (4.4") to 101.6 mm (4.0") allowing the engine to be 40 mm shorter, narrower and lighter than the Smallblock. With the new V8 tipping the scales at very svelte 180kg, the Microblock offers 8 cylinders with a mass comparable to turbocharged DOHC V6 engines. A bore of 93mm and stroke of 98mm gives a displacement of 5,326 cc (325 cu-in) in the V8 engine with 11:1 compression enabling the use of 87 octane fuel. More importantly, the same dimensions give an ideal 3,994cc (244 cu-in) displacement to the V6 and 2,663 cc (162 cu-in) in the the Inline-4. Despite the longer stroke, piston speeds at the engines' 6,000 rpm redline is actually 3.2% lower to the Smallblock 6.2L engine at its 6,600 rpm rev limit giving improved harmonic refinement. The V8 and V6 engines feature Dynamic Skip Fire technology, while all engines adopt GM's new 48v electrical system. This new arrangement ditches the starter and alternator in favor of a flywheel integrated motor-generator with 50 lb-ft @ 0 rpm and 15 hp @ 3,200 rpm, while featuring a trunk mounted Iron Phosphate battery with a 20-year/200,000 mile maintenance free service life. Also eliminated is the accessory belt and the mechanically driven water pump allowing the engine to match the electrical system's 20-year/200,000 mile scheduled maintenance interval (apart from annual 20,000 mile oil changes, filter replacement and fluid monitoring). The family is introduced with four engines a 600 hp bi-turbo version available exclusively on Cadillac vehicles as their premium power plant, a 400 hp V8, 300 hp V6 and 200 hp I4.

• 5.3L Microblock V8 Bi-turbo (LVT) -- 600 bhp @ 5,300 rpm, 600 lb-ft @ 1,600~5,200 rpm, 6,000 rpm redline (91 octane)
• 5.3L Microblock V8 (LVE) -- 400 bhp @ 5,800 rpm, 400 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)
• 4.0L Microblock V6 (LVS) -- 300 bhp @ 5,800 rpm, 300 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)
• 2.7L Microblock I4 (LVF) -- 200 bhp @ 5,800 rpm, 200 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)

Why? Because pushrods are nothing to be ashamed of. They are in fact superior for the rpm range which street cars motors operate in.

[balthazar]

GM should focus on their strengths not try to copy the Europeans overly complicated and unrelaible engineering

I dunno; the Europeans seems to make copying American hi-powered V8s work for them.

[G. David Felt]

27 minutes ago, dwightlooi said:

Let me just say this... the Blackwing V8 is probably dead given that the new 2020 Escalade DID NOT USE IT.

And, good riddance. GM should focus on their strengths not try to copy the Europeans overly complicated and unrelaible engineering paradigms when it is 20 years too late and buyers committed to European engineering hype are not going to give Cadillac a second look anyway.

Here's what I believe GM should do for the 2020s... say hi to the....

Microblock Family

The Microblock is a pushrod 2-valve per cylinder architecture scaled down from the Smallblock design. Bore spacing is reduced from 111.76 mm (4.4") to 101.6 mm (4.0") allowing the engine to be 40 mm shorter, narrower and lighter than the Smallblock. With the new V8 tipping the scales at very svelte 180kg, the Microblock offers 8 cylinders with a mass comparable to turbocharged DOHC V6 engines. A bore of 93mm and stroke of 98mm gives a displacement of 5,326 cc (325 cu-in) in the V8 engine with 11:1 compression enabling the use of 87 octane fuel. More importantly, the same dimensions give an ideal 3,994cc (244 cu-in) displacement to the V6 and 2,663 cc (162 cu-in) in the the Inline-4. Despite the longer stroke, piston speeds at the engines' 6,000 rpm redline is actually 3.2% lower to the Smallblock 6.2L engine at its 6,600 rpm rev limit giving improved harmonic refinement. The V8 and V6 engines feature Dynamic Skip Fire technology, while all engines adopt GM's new 48v electrical system. This new arrangement ditches the starter and alternator in favor of a flywheel integrated motor-generator with 50 lb-ft @ 0 rpm and 15 hp @ 3,200 rpm, while featuring a trunk mounted Iron Phosphate battery with a 20-year/200,000 mile maintenance free service life. Also eliminated is the accessory belt and the mechanically driven water pump allowing the engine to match the electrical system's 20-year/200,000 mile scheduled maintenance interval (apart from annual 20,000 mile oil changes, filter replacement and fluid monitoring). The family is introduced with four engines a 600 hp bi-turbo version available exclusively on Cadillac vehicles as their premium power plant, a 400 hp V8, 300 hp V6 and 200 hp I4.

• 5.3L Microblock V8 Bi-turbo (LVT) -- 600 bhp @ 5,300 rpm, 600 lb-ft @ 1,600~5,200 rpm, 6,000 rpm redline (91 octane)
• 5.3L Microblock V8 (LVE) -- 400 bhp @ 5,800 rpm, 400 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)
• 4.0L Microblock V6 (LVS) -- 300 bhp @ 5,800 rpm, 300 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)
• 2.7L Microblock I4 (LVF) -- 200 bhp @ 5,800 rpm, 200 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)

Why? Because pushrods are nothing to be ashamed of. They are in fact superior for the rpm range which street cars motors operate in.

Totally agree with you on the Blackwing and the over complicated Turbo mess these engines are.

Love your Microblock family idea. That I would sell to GM, Go Go Dwight!

[dwightlooi]

11 minutes ago, balthazar said:

I dunno; the Europeans seems to make copying American hi-powered V8s work for them.

Actually, they never did -- to their own detriment.

The point really isn't "high powered" V8s. The point is to ask yourself what power you need for a given application and how to most economically, reliably and efficiently produce it. At 400, 300 and 200 hp naturally aspirated, the 5.3L V8 4.0L V6and 2.7L I4 fits into the applications perfectly. A 600 hp bi-turbo is also ideal for flagship luxury cars and SUVs. You can make all that with a smaller architecture than already very small and compact small block.

The problem with DOHC designs is that there is practically NO ADVANTAGE to them. You do not need the additional flow capabilities of 4-valves per cylinder at 6000 rpm and you don't want a 9,000 rpm engine in a Malibu or Escalade. So, essentially you are paying 4 times as many camshafts, twice as many valves and lifters, more internal friction, more things to break, more things to cost more money, much heavier and bulkier heads, all for what? ABSOLUTELY no benefit.

Look... I drive an Audi with the 4.0T. I know all about its overly complicated 4.0L hot vee engine with buried oil screens, cracking PCV system, vibrating downpipes, exploding turbos and the 435 hp / 445 lb-ft it makes. Yeah, that's LS1 territory at 25% more engine mass. I get 16-18 mpg out of it in daily driving so, no it is not really more efficient -- in part because V4 mode basically do not kick in much except when you are steady at 65 on cruise control with no gradient because 2.0L off boost really isn't much. BTW, this engine only revs to 6000 rpm (5,400 when cold) so what is the point of DOHC 4-valves when we know that pushrod 2-valves flows enough air for 80 hp/L at power peaks up to 6450 rpm (LT2)?

 

[ccap41]

Isn't the DOHC thing an emissions thing? Isn't that why the downsizing and DOHC-everything became a thing? 

[Robert Hall]

30 minutes ago, dwightlooi said:

Actually, they never did -- to their own detriment.

The point really isn't "high powered" V8s. The point is to ask yourself what power you need for a given application and how to most economically, reliably and efficiently produce it. At 400, 300 and 200 hp naturally aspirated, the 5.3L V8 4.0L V6and 2.7L I4 fits into the applications perfectly. A 600 hp bi-turbo is also ideal for flagship luxury cars and SUVs. You can make all that with a smaller architecture than already very small and compact small block.

The problem with DOHC designs is that there is practically NO ADVANTAGE to them. You do not need the additional flow capabilities of 4-valves per cylinder at 6000 rpm and you don't want a 9,000 rpm engine in a Malibu or Escalade. So, essentially you are paying 4 times as many camshafts, twice as many valves and lifters, more internal friction, more things to break, more things to cost more money, much heavier and bulkier heads, all for what? ABSOLUTELY no benefit.

 

 

The benefit seems to be far greater complexity and cost to repair...a benefit to dealers and independent shops. 

[riviera74]

4 hours ago, dwightlooi said:

Let me just say this... the Blackwing V8 is probably dead given that the new 2020 Escalade DID NOT USE IT.

And, good riddance. GM should focus on their strengths not try to copy the Europeans overly complicated and unrelaible engineering paradigms when it is 20 years too late and buyers committed to European engineering hype are not going to give Cadillac a second look anyway.

Here's what I believe GM should do for the 2020s... say hi to the....

Microblock Family

The Microblock is a pushrod 2-valve per cylinder architecture scaled down from the Smallblock design. Bore spacing is reduced from 111.76 mm (4.4") to 101.6 mm (4.0") allowing the engine to be 40 mm shorter, narrower and lighter than the Smallblock. With the new V8 tipping the scales at very svelte 180kg, the Microblock offers 8 cylinders with a mass comparable to turbocharged DOHC V6 engines. A bore of 93mm and stroke of 98mm gives a displacement of 5,326 cc (325 cu-in) in the V8 engine with 11:1 compression enabling the use of 87 octane fuel. More importantly, the same dimensions give an ideal 3,994cc (244 cu-in) displacement to the V6 and 2,663 cc (162 cu-in) in the the Inline-4. Despite the longer stroke, piston speeds at the engines' 6,000 rpm redline is actually 3.2% lower to the Smallblock 6.2L engine at its 6,600 rpm rev limit giving improved harmonic refinement. The V8 and V6 engines feature Dynamic Skip Fire technology, while all engines adopt GM's new 48v electrical system. This new arrangement ditches the starter and alternator in favor of a flywheel integrated motor-generator with 50 lb-ft @ 0 rpm and 15 hp @ 3,200 rpm, while featuring a trunk mounted Iron Phosphate battery with a 20-year/200,000 mile maintenance free service life. Also eliminated is the accessory belt and the mechanically driven water pump allowing the engine to match the electrical system's 20-year/200,000 mile scheduled maintenance interval (apart from annual 20,000 mile oil changes, filter replacement and fluid monitoring). The family is introduced with four engines a 600 hp bi-turbo version available exclusively on Cadillac vehicles as their premium power plant, a 400 hp V8, 300 hp V6 and 200 hp I4.

• 5.3L Microblock V8 Bi-turbo (LVT) -- 600 bhp @ 5,300 rpm, 600 lb-ft @ 1,600~5,200 rpm, 6,000 rpm redline (91 octane)
• 5.3L Microblock V8 (LVE) -- 400 bhp @ 5,800 rpm, 400 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)
• 4.0L Microblock V6 (LVS) -- 300 bhp @ 5,800 rpm, 300 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)
• 2.7L Microblock I4 (LVF) -- 200 bhp @ 5,800 rpm, 200 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane)

Why? Because pushrods are nothing to be ashamed of. They are in fact superior for the rpm range which street cars motors operate in.

I have to admit, this microblock idea sounds great.  Since this idea is easily a descendant of the smallblock and a spiritual successor to the great 3800/3900 pushrod engines, GM should do just that rather than all these DOHC engines derived from Opel designs.  But I would do this microblock idea for one simple reason: torque.  A lot of these DOHC engines tend to lack torque at 2000rpm (they need 3000+ rpm to actually get anywhere).  Does somebody have a line to GM engineering to get them started on this amazing idea?

[dwightlooi]

5 hours ago, ccap41 said:

Isn't the DOHC thing an emissions thing? Isn't that why the downsizing and DOHC-everything became a thing? 

Not really. Down sizing is in theory for fuel efficiency. And, fuel efficiency might be an emissions thing, but no emissions standard anywhere actually cares about how many valves you have. Down sizing however hasn't proven to be all that beneficial to fuel economy. The 495hp 2020 Corvette at 3,700 lbs with 6.2 liters of pushrod power gets 15/27 mpg (it would have been higher too if not for the very short gearing to get the car to 60 mph in 2.9 secs). The C63 AMG with its 469hp 4.0TT at 3,800 lbs gets 18/27 mpg from 2/3rds the displacement. Doesn't seem like all those cams and losing 35% of the displacement helped very much. This is true not just of high power performance engines. A Chevy Cruze with it's 1.4L turbo gets 153hp and 28/38 mpg. A Toyota Corolla with a 42% high displacement 2.0L engine with turbos get 169hp and 31/40 mpg.

So, it seems that the minimize displacement while maximizing specific strategy doesn't seem to pan out.

[smk4565]

China has displacement taxes and Cadillac (And GM) is reliant on Chinese market sales.  GM sells more in China than they do in USA so they have to engine downsize.

[balthazar]

China is the biggest market for many many brands. in 2019; Mercedes sold 315K units in the U.S., and 600K in China.
A couple of years ago 50% of MB S-class's built were sold in China. Everybody is building for China.

There are numerous automotive taxes in the CDM... but the volume of luxury & premium cars keeps growing anyway.

[dwightlooi]

8 hours ago, smk4565 said:

China has displacement taxes and Cadillac (And GM) is reliant on Chinese market sales.  GM sells more in China than they do in USA so they have to engine downsize.

If that is your objective, the 4.2L Blackwing or 3.6L HF V6 still makes ZERO sense. They are not exactly "low displacement". If that is your objective, have a pair of engines specifically for those countries with displacement taxes. Like say a 0.99L I4 boosted to 160hp and 1.99L V6 boosted to 320 hp or something along those lines. And don't worry about lag either because these also use the same 48V electrics and that 50 lb-ft @ 0 rpm motor-generator helps plenty with response from 0 to 4000 rpm -- not so much to move the car but to move the engine revs to the sweet spot during a downshift for the turbos to work when you floor it. The way DC motors work is that if you start at 50 lb-ft and are down to 0 lb-ft @ 6000 rpm, you are still making 25 lb-ft @ 3000 rpm. We are not even talking about a Prius level hybrid here. No planetary gear set. Just a Iron Phoshate battery twice the size of the 12V battery you are used to and a motor that is mainly a starter and alternator.

If you are wondering why 48v? It's because it is perfect for a 50~75 lb-ft motor. Running that off 12V or 24v will mean VERY THICK cables and high amperage. You don't really need the 200+ volt electrics until you get to serious drive motors in the 150 hp class with 200~300 lb-ft. It is also exactly 15 x 3.2v Iron Phosphate cells in a series. 15 is not that much more than the stack of 10 you find in a lead acid battery to get to 12v. This keeps the battery simple and cheap.

Edited February 27, 2020 by dwightlooi

[ccap41]

14 hours ago, dwightlooi said:

Not really. Down sizing is in theory for fuel efficiency. And, fuel efficiency might be an emissions thing, but no emissions standard anywhere actually cares about how many valves you have. Down sizing however hasn't proven to be all that beneficial to fuel economy. The 495hp 2020 Corvette at 3,700 lbs with 6.2 liters of pushrod power gets 15/27 mpg (it would have been higher too if not for the very short gearing to get the car to 60 mph in 2.9 secs). The C63 AMG with its 469hp 4.0TT at 3,800 lbs gets 18/27 mpg from 2/3rds the displacement. Doesn't seem like all those cams and losing 35% of the displacement helped very much. This is true not just of high power performance engines. A Chevy Cruze with it's 1.4L turbo gets 153hp and 28/38 mpg. A Toyota Corolla with a 42% high displacement 2.0L engine with turbos get 169hp and 31/40 mpg.

So, it seems that the minimize displacement while maximizing specific strategy doesn't seem to pan out.

Obviously they don't care how many values there are. I was just in the assumption it had to do with the overall efficiency or ability to burn cleaner...somehow...

I can't imagine it getting much better with longer gears as it's an 8-spd and four of those gears are overdrive ratios. 

Emissions is not the same thing as fuel economy. That's what I originally meant. 

The Corolla does not have a turbocharged 2.0. That's an N/A engine but, I know what you mean. 

[dwightlooi]

3 hours ago, ccap41 said:

Obviously they don't care how many values there are. I was just in the assumption it had to do with the overall efficiency or ability to burn cleaner...somehow...

I can't imagine it getting much better with longer gears as it's an 8-spd and four of those gears are overdrive ratios. 

Emissions is not the same thing as fuel economy. That's what I originally meant. 

The Corolla does not have a turbocharged 2.0. That's an N/A engine but, I know what you mean. 

What I was trying to point out was that downsizing to 1.4L and packing a turbo to get in the same power bracket as a 2.0L NA engine does not actually yield ANY fuel economy advantage. I bet you that a 2-valve Inline-4 displacing 2.7 liters but running an Atkinson Cycle cam will deliver the same 150~160 hp with better fuel economy and emissions than ANY 2.0L 4-valve engine or 1.4L turbo. It'll be a bigger engine but it may not necessarily be heavier given that it ditches the big fat DOHC head.

Actually, more valves = worse emissions. Remember the 3.2L and 5.5L 3-valve engines from MB about 15 years ago? The reason they went to 3-valves is to reduce the exhaust valve surface area. Less area = less heat loss through conduction during cold starts and quicker catalyst light off. More valves also mean lower intake velocity and poorer mixing at low engine speeds. You can mitigate that with variable tumbler vanes (VW-Audi) or you can simply reduce valve lift or deactivate one valve (Honda) on a DOHC setup. But, the need for such solutions only goes to show that storm drains are not always the best when it comes to intake ports and valves.