Is low specific output the secret of engine life?

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We've all owned and know of engines that just wouldn't wear out.
Old four cylinder Hondas and Toyotas as well as BMWs and Benzes, with both diesels and SI engines represented among the MBs, as well as the old iron MB V-8s.
The Ford 300 CID inline six, the Ford 3.0 Vulcan V-6, the various Ford 351 engines, as well as the typical SBCs. Let's not even mention the enormous and impotent Cadillac and Lincoln V-8s.
Any of these engines would shrug off years of use with little wear to show for it.
What did they all have in common?
They made no power relative to their displacements.
Is low specific output a major determinant of engine life?
 
I'd say low power output, but built to take way more power than they put out. So yeah.
 
Originally Posted By: fdcg27

Is low specific output a major determinant of engine life?


No. Compare Tractor engines (18 wheelers). Specific output that is right in line with a modern turbo engine and they last millions of miles.

It's all the design. You can design for high output and high life. Or low output and low life.
 
Not abusing the engine is more important, also regular maintenance.

All my Hondas are low performance and will last a while.
 
Originally Posted By: buck91
What about engines such as the Ford 4.6L?


Which typically make less than 60 bhp/liter?
 
Originally Posted By: itguy08
Originally Posted By: fdcg27

Is low specific output a major determinant of engine life?


No. Compare Tractor engines (18 wheelers). Specific output that is right in line with a modern turbo engine and they last millions of miles.

It's all the design. You can design for high output and high life. Or low output and low life.


Diesel engines are massively over built for their output, typically weighing more than twice as much as a gasoline engine of the same displacement and output.

Even there, specific output and life of their marine versions is directly related.

It should be more accurate to say that there can be a relation between engine life and specific output between engines of the same design or family.

This is most clear in the aviation industry where specific output increasing in an engines will cut hundreds of hours off of its rated life.
 
276hp from a 4.6 sounds like high output.


I believe the OP is blinded from today's engines that use turbos, high(er) compression, Variable valve timing and probably alot of other (cheats) that IMO do nothing for a street car and are more for the racetrack (or police pursuit type motoring).
 
Those engines also tended to be in more expensive or family-oriented vehicles. Vehicle price used to be a rough correlation to how it would be maintained. A person buying a Lincoln or Caddy would tend to have more income available to pay for routine maintenance. Folks would also maintain the Family Truckster so it didn't break down when taking the screaming toddler to the doctors.

On the cheap car side, examples of fairly indestructible engines are the Hyundai Alpha/Beta engines and the GM OHV 2.2. Those are well-known to be fairly robust engines with little to go wrong despite indifferent maintenance.
 
I would say no, but most of the higher output engines don't become long distance daily drivers. There is a 650,000+ LS1 Corvette rolling around. I know of a guy with a 2003 Mustang Cobra that is around 400,000 miles. That's a supercharged engine.
 
Originally Posted By: mjoekingz28
276hp from a 4.6 sounds like high output.


I believe the OP is blinded from today's engines that use turbos, high(er) compression, Variable valve timing and probably alot of other (cheats) that IMO do nothing for a street car and are more for the racetrack (or police pursuit type motoring).


Not really.
Anything in my sig has higher specific output and none are what could be termed performance engines.
 
Originally Posted By: fdcg27
We've all owned and know of engines that just wouldn't wear out.
Old four cylinder Hondas and Toyotas as well as BMWs and Benzes, with both diesels and SI engines represented among the MBs, as well as the old iron MB V-8s.
The Ford 300 CID inline six, the Ford 3.0 Vulcan V-6, the various Ford 351 engines, as well as the typical SBCs. Let's not even mention the enormous and impotent Cadillac and Lincoln V-8s.
Any of these engines would shrug off years of use with little wear to show for it.
What did they all have in common?
They made no power relative to their displacements.
Is low specific output a major determinant of engine life?

Either Honda S2000 engine is exception or it depends on how the engine is designed/manufactured. 110-120 HP per liter(and passed US emission) is not low by any standard.

I just posted second UOA of my S2000 with PP 10W30, wear metal was low for both analysis. Engine of S2000, Ap1 and AP2, are known to be very reliable and AP2 didn't consume measurable amount of oil during standard OCI around 6-7k miles. AP1 is known to consume some oil, if it is top off to keep oil level above add line it can run almost for ever.
 
Originally Posted By: fdcg27
Originally Posted By: buck91
What about engines such as the Ford 4.6L?


Which typically make less than 60 bhp/liter?



Even my stock GM 5.7L engine doesn't make more than 60 bhp/liter. And it's certainly a performance engine.
 
Originally Posted By: itguy08
Originally Posted By: fdcg27

Is low specific output a major determinant of engine life?


No. Compare Tractor engines (18 wheelers). Specific output that is right in line with a modern turbo engine and they last millions of miles.

It's all the design. You can design for high output and high life. Or low output and low life.


You need to explain this further because at face value it doesn't make sense. The Cummins ISX, in top trim, is 600HP. That's a 15L engine. That's 40HP/L or a relatively low specific output.

Assuming you are keeping this focus entirely on diesel engines, in comparison the Mercedes Diesel in the GLE 350d is 3L and 249HP, or 83HP/L.
 
For every manufacturer in your examples, we could find engines of the same specific output that were doomed by design flaws and manufacturing failures. For example, Ford 3.8 head gaskets, 4.0 SOHC timing chain explosions, etc.

The secret of engine life is having engineers who aren't idiots design it, and having great manufacturing processes to make sure it's put together right.
 
Originally Posted By: dblshock
Checker Cabs...


Checker just used off the shelf GM powertrains because they are freakin' awesome.
 
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