Engine/Transmission (1998.5 - 2002) The effects of higher HP on longevity / reliability

[PRyker]

My interest on this was sparked in another thread and thought I would start a thread specifically about this subject. I am very interested in understand what the impact of slowly raising HP on our trucks with things like injectors, fueling boxes, timing boxes, larger turbo's etc... is having without us knowing right away? What failures have others experienced?



My thinking here is that a lot of people have been doing this and are unaware of the proper way to truly build up a high performance engine. I think often things like valve springs, valves, pistons, piston rings, etc... are often overlooked. If so, what has been the true impact on lengevity and reliability to these engines?



Also, if you were going to build a 600 HP Cummins 24V the *right* way from the ground up for both power as well as reliability and longevity what would you do? Money is not an object!



Here is what I have learned so far...



1. Ceramic coated pistons

2. *better* piston rings (not really sure what kind)

3. O-ringed head AND block

4. good head gasket

5. different Cam

6. stiffer valve springs

7. stronger valves??

8. ported and polished head



What am I missing? what else have others done. How "bulletproof" would an engine with the above be?



Thanks



Phil

 

[PRyker]

Some other thoughts...



What effects does black smoke have on the inside of your combustion chamber. Seems to me it is popular for people to want to "smoke" out others and I would bet that there has to be some negative effects of the soot in the combustion chamber.



I have changed injectors on a truck that smoked and one that didn't and I can tell you that the one that smoked was MUCH MORE filthy then the one that did not. A lot of gritty soot on the injector tips for the one that did smoke. Seems to me all that grit has to have some effect on the rings, valve seats, etc...



Thanks



Phil

 

[RustyJC]

Just a comment from the conceptual point of view. Smokey Yunick (the NASCAR legend) was asked a very similar question decades ago. His response was something to the effect that "... an engine has a finite number of BHP-hours designed into it. You can take a little BHP out for a long time, or you can take a lot of BHP out for a short time. " I guess the ultimate example of this is a Top Fuel drag racing engine.



Yes, the Cummins is overdesigned for our application, but those of us who have "cranked up" the output substantially may well have turned a 1,000,000 mile engine into a 500,000 mile engine. I doubt there's enough factual data to quantify accurately just how much life we sacrifice for every 50 BHP we add to the engine's output, however.



The other thing to consider is, just because I have a ~400 flywheel horsepower engine (versus 245 BHP stock), what percentage of its life is actually spent running at that power level? If I'm cruising down the Interstate at 70 MPH pulling our 5th wheel on level terrain, the engine is developing the same actual BHP output (maybe 150 BHP or so - I haven't run the math) in its 245 BHP configuration as it would in its 400 BHP configuration, right? I think the key factor is probably BHP-hours produced insofar as lifespan is concerned. Caterpillar even schedules maintenance based on the amount of fuel consumed - a roundabout way of measuring BHP-hours produced.



Rusty

 

[FourBarR]

i would say if your going to spend all that money, make sure you dont have a 53 block. after reading cummins report on the whys of the cracking, it would seem that increasing hp will only increase the possibility of it cracking. my 2 cts.

 

[OTRPU]

My experience. . . and it's cost me dearly. Not only does it add greater physical stresses, it allows the opportunity for mistakes to be made while rebuilding. Problems here should be covered be the person that benefitted from making the changes. Sadly. . . this doesn't always happen. Guys I know leave um bone stock, work um daily for 6 months, then sell it and get another. Let somebody else deal with the problems. And the new buyer feels lucky he's found such a bargin with only 108k on it. Do ya feel lucky? Truth is, everytime you turn it on it takes it's toll.



Cheers,

Steve J