Argument with co worker

[Donald]

Originally Posted by Dylan1303
Where talking about cars and what not, then co worker said any mod you do to increase power shortens your motors life. He claimed putting a header on his 4.0 jeep will shorten his motor life, but the power increase is worth it. I disagreed with him say basic bolt ons dont decrease life. I could agree about putting a bigger turbo on a diesel might but i have to say hes half right.


The Jeep 4.0 engine will die from piston skirts cracking before the headers effect it.

 

[Donald]

Originally Posted by SubieRubyRoo
Never argue with an idiot. Onlookers may not be able to tell the difference.


Agree. You can quickly conclude "what's the point of arguing with this guy."

 

[littleant]

Originally Posted by dishdude
I think most people adding performance mods drive the heck out of them which decreases life. So I would say you're both right.

^This Here^ The more power the more you will use that power. Been there done that.

 

[alarmguy]

When you alter the design of an engine with after market products without question that you open yourself up to decreased engine life, thing is nowadays engines outlast vehicles so its most likely not an issue.
In this case I am not saying for sure adding headers will decrease engine life but I will go back and say when you modify an engine from its design chances are you are decreasing engine life as the manufacturers know way more then you when the engine was designed.

 

[philipp10]

Engine life is dependent upon how much horsepower it is being run at. Adding headers doesn't necessarily mean it is being run at higher hp. Headers do make it possible to run at higher hp, but only if you want to go faster.

Seriously, unless your thrashing on your car, your splitting hairs here. More than likely the car will die of something else first.....

 

[alarmguy]

Originally Posted by philipp10
Engine life is dependent upon how much horsepower it is being run at. Adding headers doesn't necessarily mean it is being run at higher hp. Headers do make it possible to run at higher hp, but only if you want to go faster.

Seriously, unless your thrashing on your car, your splitting hairs here. More than likely the car will die of something else first.....


I agree but also read my post above. Manufactures know more then us and anyone in this forum. Chances are any mods to an engine will open one up to decreased engine life, whether or not something simple like headers will no one would know but it will not increase engine life.

People tend to look at simple numbers to complex computer designed engines, the old days are gone, new engines truly are precision computer control machines. Upsetting the balance of the whole does not help.

Simple example, "adding headers doesn't necessarily mean it is being run at higher hp" I agree, chances are the computer will not allow and HP change but, adding headers might alter the AFR if the computer is unable to compensate for it, this could result in slightly leaner burn conditions then already present and super heat the cylinders.
Just talking here ...

 

[philipp10]

Originally Posted by alarmguy
Originally Posted by philipp10
Engine life is dependent upon how much horsepower it is being run at. Adding headers doesn't necessarily mean it is being run at higher hp. Headers do make it possible to run at higher hp, but only if you want to go faster.

Seriously, unless your thrashing on your car, your splitting hairs here. More than likely the car will die of something else first.....


I agree but also read my post above. Manufactures know more then us and anyone in this forum. Chances are any mods to an engine will open one up to decreased engine life, whether or not something simple like headers will no one would know but it will not increase engine life.

People tend to look at simple numbers to complex computer designed engines, the old days are gone, new engines truly are precision computer control machines. Upsetting the balance of the whole does not help.

Simple example, "adding headers doesn't necessarily mean it is being run at higher hp" I agree, chances are the computer will not allow and HP change but, adding headers might alter the AFR if the computer is unable to compensate for it, this could result in slightly leaner burn conditions then already present and super heat the cylinders.
Just talking here ...

agree....but your splitting hairs here. Just remember while the electronics on engines are more advanced.....it's still basically just a a piston sliding in a cylinder....same as it's been for over a century.

 

[WyrTwister]

Originally Posted by Dylan1303
Where talking about cars and what not, then co worker said any mod you do to increase power shortens your motors life. He claimed putting a header on his 4.0 jeep will shorten his motor life, but the power increase is worth it. I disagreed with him say basic bolt ons dont decrease life. I could agree about putting a bigger turbo on a diesel might but i have to say hes half right.



Just a guess . I think it depends A , on how you drive it & B how much the engine was over built / over engineered .

 

[chainblu]

Originally Posted by WyrTwister
Just a guess . I think it depends A , on how you drive it & B how much the engine was over built / over engineered .


Right. This isn't a race engine built on the ragged edge of durability to only last 500 miles or 1/4 mile. Manufacturers engineer quite a bit a cushion into engine designs for longevity sake. Otherwise, the first person to use a K&N air filter would send the rods flying thru the oil pan. LOL

 

[alarmguy]

Originally Posted by chainblu

Right. This isn't a race engine built on the ragged edge of durability to only last 500 miles or 1/4 mile. Manufacturers engineer quite a bit a cushion into engine designs for longevity sake. Otherwise, the first person to use a K&N air filter would send the rods flying thru the oil pan. LOL



Very well said!

 

[Eddie]

Defuse the argument by telling him he is probably correct but, you will like the sound anyway. All will be happy with this win-win. Ed

 

[eljefino]

Originally Posted by alarmguy


I agree but also read my post above. Manufactures know more then us and anyone in this forum. Chances are any mods to an engine will open one up to decreased engine life, whether or not something simple like headers will no one would know but it will not increase engine life.

People tend to look at simple numbers to complex computer designed engines, the old days are gone, new engines truly are precision computer control machines. Upsetting the balance of the whole does not help.



I would agree if you're talking about the little 4 cyl turbos pulling buicks and what not around. Yes they have a "cushion" but if you start messing with them you'll run out of cushion rather quickly.

The engineers, particularly the ones driven by idiot-proofing cars to get them through warranty, will take power away from certain specific operating conditions: Very cold, very warm, lousy gas (or even normal 87), mid-shift in the trans, specific trans gears, etc. Tuners put that power back in but at that point it's sparring with the OE over a specific decision. Versus "oh Jeep just went with this cast manifold because it's cheaper, easier to assemble at the factory and the car sounds quieter for Grandma to buy it."

 

[JHZR2]

Originally Posted by ZeeOSix
Originally Posted by JHZR2
Engine life is essentially time at temperature. A mod in and of itself will not necessarily increase these metrics, unless more power is consistently employed.


Avg amount of HP it has put out over time is also a factor. An engine idling for 1000 hrs isn't going to wear as much as the same engine running WOT (at max HP output) for 1000 hrs. Parts like rings, pistons, wrist pins, rod and crank bearings get increased loads on them when the engine is putting out max HP and high RPM.


Agree. I was using "temperature" as a proxy for firing temperature and/or loading.

Higher power density also drives certain considerations.

 

[DoubleWasp]

Way too many factors to call it wither way.

It's like saying changing your cologne will get you twice the women.

There are "power" mods that address design deficiencies and actually increase the durability and therefore life of the engine. There are engines so overbuilt that they couldn't care less.

Manufacturers regularly modify their own designs to make 100-300HP more than the original architecture did without engine life going down the toilet. But a set of headers is going to cut the life an engine? GTFO.

Maybe that was true in the 50s or something.

We just finished work on an old Betram Cruiser boat with GM 454 engines. Their situation?

*Exact same components as land engine except for camshaft
*Cruise at 100% more rpm than land engine
*100 more HP than land engine of same vintage
*Cruise achieved with maximum load on each engine (that's just how propeller selection works)
*3000 hours on both engines
*160psi compression across all cylinders (+/- 8 psi)
*Cross hatching still visible in all cylinders
*40 psi hot oil pressure at hot idle
*Flat tappet camshaft shows minimal wear

I don't know where the cutoff point is for this "loss" of engine life, but it must be so far that it doesn't actually matter, if it exists at all.