Improved engine longevity

[trinacriabob]

I have read numerous comments in auto mags and auto guides that newer engines are more efficient and lasting longer? I am in the 200,000 mile club myself (the first time).

So what are the reasons? Lower rpms by additional gears, better tolerances in the factory, fuel delivery systems?

Please chime in on what is making engines last considerably longer. I am curious. The one that stumps me the most is fuel delivery? How does multi port fuel injection improve the longevity of the engine over carburetion?

[Hudson]

I have read numerous comments in auto mags and auto guides that newer engines are more efficient and lasting longer?  I am in the 200,000 mile club myself (the first time).

So what are the reasons?  Lower rpms by additional gears, better tolerances in the factory, fuel delivery systems? 

Please chime in on what is making engines last considerably longer.  I am curious.  The one that stumps me the most is fuel delivery?  How does multi port fuel injection improve the longevity of the engine over carburetion?

Not only fuel injection which allows fuel to burn more completely and leaves fewer unburnt remnants behind (to cause friction) but also cleaner fuels. Don't forget better lubrication and lubrication systems...more focus on changing oil (which alone should allow a modern engine to reach 200,000 miles and more).

[balthazar]

I agree: better lubricants, cleaner burns, lower overall RPM, lighter reciprocating assemblies all result in less wear/ increased longevity.

[andretti]

The one that stumps me the most is fuel delivery?  How does multi port fuel injection improve the longevity of the engine over carburetion?

Multiport fuel injection delivers the optimal fuel/air ratio to each cylinder. Carburation has several problems with optimal fuel delivery that effect longevity.

First at cold start carburators tend to deliver too much fuel to the inboard cylinders (closest to carb) and can wash the oil off of the cylinder walls if the mixture is rich enough thereby effecting longevity through the reduced lubrication in the inboard cylinders.

Second when fully warmed up and running hard the outboard cylinders (furthest from carb) will run too lean and too hot (oxydizing the cylinder lubrication) creating a tendency to score the outboard cylinders over time effecting longevitiy

Edited February 9, 2006 by andretti

[funkypunnk]

Metallurgy, computer controls, advanced air/fuel management, and advances in lubrication!

[cmattson]

Teflon

(sorry - I'm always trolling for a joke, no matter how lame).

Actually, I think there are a few excellent reasons why:

1) Computer processing power. Faster computers, better graphics = more powerful engineering software. Engineers can model and test parts well before building a mock up.

2) Oil has removed remarkably

3) Competition.

[ponchoman49]

I remember what killed a lot of engines in the 70's and 80's was out of tune carbs, bad oxygen sensors or faulty temp sensors which caused many an engine to run too rich which in turn litterally washed out the bearings and cylinders. I have a 1980 Grand Prix SJ with a Pontiac 301 4 bbl, an engine not know to last much past 100-150 k miles. Yet here is my Grand Prix with over 150K with the only engine work being a new timing chain and valve cover gaskets with almost perfect compression on all 8 cylinders and no strange noises or knocks. The reason.... maintenance. Oil gets done evey 3000 miles. The carb was rebuilt around 100K. The antifreeze has been changed every 2 years. So in theory the engine always has fresh oil/antifreeze and never is allowed to run rich or poorly. The modern engines most always run perfect with fuel injection and seldom have rich running conditions and such. Add to that better modern day oils, more precise fuel delivery systems and improved quality gaskets and such and it's no wonder newer engine last so long. The biggest reason for so many engine failures years ago was lack of maintenance.

[rkmdogs]

Metallurgy, computer controls, advanced air/fuel management, and advances in lubrication!

I agree 100% with your assessment, and would also like to add,

a higher level of sophistication in measurement and analysis equipment, to

observe and evaluate the details and results of change better.

The rumor that I heard when the old "B' body cars were alive, was that the LT1

series of engines was mandated to last 300,000 miles for heavy-duty fleet

and police use! I think the designers and engineers succeeded!

That is not to say that pheripherals would not need service or replacement,

but the basic core does meet this criteria.

[PurdueGuy]

Multiport fuel injection delivers the optimal fuel/air ratio to each cylinder.  Carburation has several problems with optimal fuel delivery that effect longevity.

That'd be more like direct injection. Still, it's a much closer to optimal a/f mix.

[76ChevyTrucker]

Another thing is the closer tolerances that engines are built to today as compared to say, my Chevy 350 in the '76 pickup I have, now I admit that its a powerful monster (385hp to the rear wheels), but the tolerances are a LOT larger than on a car of today. Although I will admit that my truck ran for 196,587 miles before both head gaskets gave up the ghost and I rebuilt the engine, bored it .040 over, put a hotter cam in it, did a little magic to the Holley Street Dominator 600cfm 4bbl, along with a few other modifications, but the basic block hasn't been really touched, nor has the crank, and I still have the original cam stored and ready to rock and roll in another engine if need be. I have to admit that the engines will run forever if they're properly maintained. My granddad has a 4.3L in his '89 Blazer that gets the oil changed every 3 months (doesn't do enough driving to work the 3,000 mile limit) antifreeze flushed and refilled every 2 years, transmission flushed and refilled every 100,000 miles and he's currently got about 180,000 on it and hasn't run into problem #1 yet, unless you count a finally burned out distributor cap and rotor button and a Coolant Temp Sensor as major, stop-the-earth's-rotation problems.