Engine life. Bombed vs not?

[RonA]

Has anyone done a comparison on engine life between a mild motor,say 350hp vs a higher output motor, say 475 to 500hp?More gas blowing past rings and more force on top half of rod bearing as boost goes up or timing advances. Is that where the failures occur?

RonA

 

[Snow man]

As hp goes up,engine life does goes down accordingly. I wouldnt expect a 450hp B series to last much over 200K if the powers used often.

 

[CChase]

Read somewhere (take it FWIW) that diesel engines have basically a defined lifespan that can be measured by amount of fuel burned. More power = more fuel = shorter life span. Babying the go pedal and taking it easier = longer life span. Don't know how true it is, but seems that it would make sense.

 

[Sageair]

There was a great article in Flying magazine that basicall said what CChase did. Horsepower=wear. There are many aircraft engines available in normally aspirated and turbocharged models. The T. B. O (time between major overhaul) is typically 200 hours less on the turbo version. Interesting part is that in aircraft both versions are rated at the same horsepower but the turbo version makes more power at altitude therefore spending more hours at higher power settings.

 

[jarsong]

Originally posted by CChase

Read somewhere (take it FWIW) that diesel engines have basically a defined lifespan that can be measured by amount of fuel burned. More power = more fuel = shorter life span. Babying the go pedal and taking it easier = longer life span. Don't know how true it is, but seems that it would make sense.

Hmmm, So if your Mod Increases your mileage you'll get more life... . I think this is more of a HEAT/pressure issue. WHo knows?

jarsong

 

[CChase]

Originally posted by jarsong

Hmmm, So if your Mod Increases your mileage you'll get more life... . I think this is more of a HEAT/pressure issue. WHo knows?

jarsong

Prolly if you keep your foot out of it, when black smoke starts rolling, I don't think that goes very far as a mileage increase.



I would think it relates to efficiency. If your engine is running efficiently (low intake restriction, low exhaust restriction, optimum timing, optimum spray patterns, etc), it is less taxing on the engine and as a result should get better mileage = less fuel = longer life... . dunno. It seems to me that it may not be the pounds of fuel burned that is the direct cause, but instead it is a related indicator of how things are working within the engine.



Just something I read. Probably not a bulletproof theory, but in general it seems to make sense to me.

 

[Joe G.]

I don't think the aircraft to highway use comparison works. It would work to compare aircraft to marine.



With these engines I think it depends more on driving habits and maintenance. If you flog a stocker hard and don't do the maintenance like it should be done, it won't last as long as a bombed truck that is driven sanely and well maintained. In my case, I have plenty of power when I want it, but normal use by me does not need that kind of power often.

 

[DavidTD]

Talking to one of the Cummins guys at a TDR event years ago. I asked him about my choice to add 275 injectors and VA box to my 24v and what it did my my engine life. His response was that I had shortened the life of the motor will everything else remaining equal. I asked him by how much, he said we'd find out as he had the same mods done to his personal truck. In a nut shell, he guessed we'd both eventually sell perfectly running trucks.



I believe it's obvious one of these motors is not going to work at peak power for very long if it is making big power. Boost, timing (cylinder pressure) and RPM are hard on bottom ends.



So far I have 108k on my 12v. Since 48k, when I bought it, the truck has been at minimum 350hp, and mostly around the 430 - 450 range. It has run lots of timing, lots of fuel and between 45 and 60 psi boost. I don't run this truck hard as often as some, it travels a lot of easy highway miles, and has it's time at the strip now and then. I don't expect more than another 50k or so miles until I'll be rebuilding. If it goes more, great. Less, oh well. But my feelings will be a total of 150k miles out of a 400+rwhp engine is pertty darn good.

 

[RonA]

Thank you for the information. I will be running twins with the wastegate set somewhere between 50 and 55lbs. This should be

around 425 hp with this motor. I will be pleased if this setup will run 100k from this point. It was stock for first 25k. That will give me 4 or 5 years worth of running and plenty of time to build it's replacement.

RonA

 

[Vaughn MacKenzie]

With higher HP, careful maintenance is more critical, however with responsible use of the increased power you should still get a lot of miles out of your rig. One of the biggest factors: Keep the EGTs in check!!



drawson did a rebuild after damage from a turbo failure and after running high HP over the last 130-140K (he had close to 160K on the motor) there was very little sign of wear.



Jason Burton of NW Custom has flogged the snot out of his '97 12-valve and it has held up well. He has close to 200K on his and has run high HP since it was nearly new, and especially the last 3-4 years he's been way up there in power, like 500-600hp plus, and now has twins.



Vaughn

 

[jarsong]

I think next year I'm going to turn up the heat a little. Saving for the guages and SB clutch for the proper foundation, then it will be turn up the heat time... DC can go to hell! If it breaks, I'll fix it.

jarsong

 

[drawson]

From what I have seen hopping up the mighty Cummins might take some life away, so instead of gettting 1,000,000 mile it might only go 800,000



From waht I saw inside my motor it would have gone at least 500,000 mile with no problem. It had been over 400 RWHP for 3 years. It had 168K on it went the turbo blew and there was no cylinder wear at all. I put standard diameter pistons back in it.



Here is my take on engine life. If you use the HP all the time it will wear out faster, but if you stay stock and always have your foot to the floor it isn't going to live long either. As I have found more and more power I find I very rarely put the peddle to the metal. there just isn't enough road to hold it down that long. I also am able to tow at a lower peddle setting than before.



IMO engine life is more depent on your right foot than where the motor is built too

 

[Snow man]

From what my motor looks like internally,as compared to Drawsons, i can say that twins/nitrous both will dramatically shorten engine life if the power is used.

 

[amillstream]

I don't care if your stock or not, I'm saying that unless you burn one up (egts), you will wear the truck out long before the motor goes. There is no way I could put 300,000 plus miles on my truck the way I use it. I think I could wear out 3 of these trucks with one motor. Well, at least 2.

 

[Big_Daddy_T]

Mine had 150k. I had run the snot out of it sinced day one. Supermentals and drag comp on 5x5. It still turned in phenominal mileage and still had stock blowby even with 40+lbs of boost.





I cannot recall any bearing related failures on this website since I signed up several years ago. Inline 6s tend to tolerate uprates well. They are bombproof. I do not think it is a factor. These things make 250k in apps where they are overloaded day in and day out. Our little pickup is a joke to this powerhouse.

 

[Snow man]

amillstream, i disagree. I have 94K on my engine,i didnt burn it up EGT wise. But the engine is just worn out. Granted I did run it hard,and for the last 15K it had twins,and the last 25K it had N2O,which i only ran about 35-40lbs thru it total. Both my VP44 and DTT trans outlived the ISB,in my case.

 

[PUMPERDUDE]

Just say NO to drugs

 

[Snow man]

I think it was more the incorrect use of drugs than the drugs themselves. Live and learn.

 

[Vaughn MacKenzie]

Big Daddy T I remember one guy running an FL70 with the 5. 9 which was cranked up and he ran it hard and loaded all the time. Mid-upper 300s HP and long grades sustained heavy pulling. I believe it was at 350,000 miles he said they did an inspection teardown and all they ended up replacing was the rod bearings even though it didn't really need it. As I recall he was near 500K the last I saw any posts from him (handle was FL70 or something like that).



Another example is livinez_123 on NW Bombers, he's had a TST plate in his old rig ('97 dually) since around 140K as I recall and it's still running strong 360,000 miles later even towing heavy for much of that (he passed 600K about the time he took delivery of the 04. 5). That truck is for sale by the way, nice rig for $6500.



Vaughn

 

[Tomscreek]

So in my case I'm just hoping to get 200,000. miles out of mine. It's an 01 with 60,000 miles on it now, bone stock engine. 90% of the miles are traveling 10 miles one way to work on the interstate at 65 mph. I pull a 4 horse trailer about 10 times a year for and hour and a half each time. I plan on puting EDM 1. 5's on it next year and nothing else. I change oil every 4000 miles and have used Delo 400 since new. Think it will make 200,000?