High Hours and Service Life?

[a64pilot]

However it has been documented more than a few times I’m sure that wear does not increase linearly with RPM, but a great deal more, it seems to follow closely to how much energy is in the reciprocating mass, you know E=MC2
So higher RPM does increase wear.

[hellosailor]

One reason that long haul truckers always idled (and usually still do) is the damage that starting and starting does, on the entire system. And if they can't re-start, a fast $50,000 in perishable produce may be trashed, making "starting" rather crtiical.
The starter motor on a diesel truck can throw a 2000 volt spike when it disengages, higher than the 600V spike most automobiles throw. These spikes can kill other electricals. There are also "just this many" starts in each starter motor. For instance, some of the new cars with "autostop" that shut down at traffic lights and restart immediately afterwards? Those are *all* built with oversized enhanced starter motors to compensate for the wear. So the truckers idle because fuel was, and is, in the long run way cheaper than the startup and shutdown surges on starters, alternators, lost time in the shop to replace those more often (if you start up five times to refuel on one trip, instead of just once, you'll be in the shop five times more often getting your starter replaced!) and all the rest.
Thanks to a US Navy purchasing requirement pre-WW2 "If you want to sell vehicles to the USN, they will have full oil pressure within 20 seconds of startup" the entire auto industry has been making engines that are fully operational and start-up oiling and heat issues haven't really been a problem for a long time.
But all the other stresses of startups and shutdowns (more spikes) are still there. Compared to that, fuel has always been cheap. (Like big dumb overbuilt engines, that just need fuel and oil. In the long run, that's the cheapest way to build them.)

"higher rpm does increase wear" Yeahbut.
Yamaha, who stared with high rpm racing motorcycles, and then Toyota, who went into 7500-rpm four bangers by 1980, proved that's all depending on context. If you use right right choice of alloys and metal treatments, you can chose which parts take the wear. Like wearing out replaceable piston rings instead of cylinder walls.
And if you want efficiency, you want enough piston speed to "chase" the duration of the flamefront in the cylinder, so you time the piston to allow just enough space for the flamefront to keep expanding and not hitting the cold cylinder head and quenching too soon. There are optimal design points for the whole setup, and once you reach them, you can deal with the rpm's by engineering choices.
For years Mercedes Benz diesels (auto) used to burn a quart of oil every thousand miles, while burning that in less than 5000 was unacceptable in the US. "Oil is cheaper than piston rings, so we use loose rings that burn oil but don't put any wear on the cylinder walls." Well, that's one way to do it.
Modern synthetic oils with radically different thin-film (sheeting) characteristics also make a difference. That's partly why Toyota specs 0-20 instead of 10w40 now. The old thick oils actually don't contribute anything in the newer engines with tighter manufacturing tolerances, they just gum them up!
It IS very much "Any sufficiently advanced technology will be indistinguishable from magic."
The problem is, figuring out which is magic, and which is just hucksterism.

[a64pilot]

I’d agree with most of that, except the major importance of higher RPM is piston speed, it’s entirely possible that a low turning, long stroke motor can have a higher piston speed than a high revving bike.
My CBR-1100XX had the highest piston speed of any mass produced engine when it was built and for a bike it had a relatively low Redline of only about 10,500 RPM, but it was a long stroke motor for a bike, where there were bikes turning over 14,000 RPM that had lower piston speeds.

Idling your truck is now illegal in many places, reason that many now have small hen sets.
Heck it seems the EPA has even published a list of places you can’t idle
http://www.murcal.com/pdf%20folder/1...tions_lit1.pdf

[Wotname]

Another way of thinking about how many rebuilds you can get out of engine is where / how the serial number is located .

If cast or stamped somewhere, it can be rebuilt as many times until that "somewhere" is no longer serviceable.

If it is riveted on serial number plate, then the number of rebuilds is extended until the serial number plate corrodes away or is otherwise damaged to be unreadable.

[Jim Cate]

Originally Posted by a64pilot

However it has been documented more than a few times I’m sure that wear does not increase linearly with RPM, but a great deal more, it seems to follow closely to how much energy is in the reciprocating mass, you know E=MC2
So higher RPM does increase wear.

I surely agree that wear increase with RPM is superlinear, but the equation you quote has nothing to do with it! That one relates to the conversion of mass to energy as in nuclear processes as in fission or fusion. These modern ICEs are pretty powerful, but fall short of such events.

Jim

[a64pilot]

Jim I believe that equation is also used to determine the kinetic energy of a moving object.
But I suck at math so I’m not certain.
It is I believe simply Energy is equal to mass times velocity squared, showing of course that of the two mass and velocity, it’s velocity that really imparts more energy than mass.

[Jim Cate]

Originally Posted by a64pilot

Jim I believe that equation is also used to determine the kinetic energy of a moving object.
But I suck at math so I’m not certain.
It is I believe simply Energy is equal to mass times velocity squared, showing of course that of the two mass and velocity, it’s velocity that really imparts more energy than mass.

Jody, the "C" in your equation is the speed of light and has nothing to do with kinetic energy

The equation that you are thinking of is KE=1/2MV^2.

I knew what you meant but was trying to add a little levity. Sorry if it sounded bad to you... but 900 hp pickup trucks sound kinda nuclear to me.

Jim

[a64pilot]

Your right, as I said I suck at math.
How about 800 HP Cadillacs? This is the Wife’s car, not this one, hers is in storage, but it’s tempting. It’s already a sleeper at over 400 HP, but 800 would be cool. Have to be careful with the drive line though.
https://www.lingenfelter.com/?_vsref...hoCCo8QAvD_BwE

[Jim Cate]

Well, that is pretty impressive! I got out of the race car biz in the late 60s, when I sweated blood to get around 400 hp out of a small block chev base. Those store bought engines are pretty sophisticated, and pretty expensive and for me, would have taken most of the fun out of racing. Way different mind set these days, I guess.

Thanks for the link... I guess I'm REALLY out of touch with current reality!

Jim

[hellosailor]

f=m*(v^2) yes.
But aside from valves slapping into valve seats, what else has to go bang that way? Pretty much everything in an engine is built to a price. Pretty much anything on the mass market can be made bulletproof--at the right price. Like dropping in forged connecting rods instead of cast ones.

[a64pilot]

Jim,
Even 20 yrs ago when I was still playing with cars there was something called LS1 edit, it was software. You could plug into the OBD2 port and adjust rev limiter, Recurve spark advance, enrichen or lean mixture at different throttle positions and openings, adjust the knock retard. Remember it has an O2 sensor so it know mixture ratio at all times. Many other parameters I don’t remember.
If it was an automatic transmission, you could change pressures, shift points and shift firmness / clutch slippage.

All without opening the hood or you tool box.

I put a Venom nitrous kit on our old 93 Z28 when the wife got her 02 SS Camaro, one of the very last ones made.
The Venom kit was neat because it wasn’t on or off, it had a variable valve and you could set up a curve with throttle opening and RPM /Vs nitrous flow. It flowed no fuel, it tied into all the fuel injectors and became the fuel injection computer, and used the O2 sensor to both keep the mixture correct and shut down nitrous the instant you went lean. A seamless smooth extra 200 HP or less if you wanted.

What can be done today with computers is nothing short of amazing. The Wife’s CTS-V caddy idles smooth as glass and gets 25 MPG on the highway, but is the worlds quickest and fastest four door car.

[moseriw]

Easy answer: get a low 1800 rpm old (up tgo 1980 tractor engine without any common rail or turbo scrap and I think you will have 60.000 hrs for sure without refurbishing.

But only use coolant and change engine oil every year independent of hrs.


With new engines - you name the type - you will be lucky to reach the 10.000 due to
2500 to 3300 rpm marching.

[EngNate]

I've never worked with any 'large' engines, 3000HP is the max. The most hours I've personally seen on an engine [I]without overhaul[I] was 25,000. That was a Cat D-398, 850HP @ 1250 max rpm. and weighs aprox. 15,000 Lb. It was still running fine when torn down, started easily and used a modest amount of oil. We did find that one piston skirt was cracked. It had been run at 80% power 90% of the time. It had an oil prelube system and was never started without oil pressure.

[Cheechako]

"higher rpm does increase wear" Yeahbut.
Yamaha, who stared with high rpm racing motorcycles, and then Toyota, who went into 7500-rpm four bangers by 1980, proved that's all depending on context. If you use right right choice of alloys and metal treatments, you can chose which parts take the wear. Like wearing out replaceable piston rings instead of cylinder walls. "
Even if those four bangers were to designed so they could go 7500 rpm, the bottom line was they went the same rpm as others at hiway speed.... less than half that. And of course in a racing context, lasting just one race is enough.

[CaptJPMcGuire]

John Deere 6404 Marine-zed by American Diesel for Grand Banks in 70's
Running Rotella T 5w-40 and Lucas Oil Stabilizer. 6,000 hours. The max rpm I run is 1800
at 7 kts. usually at 6.5 1500. Use Howes fuel treatment qt to 300 gal.
I have oil pan and some seal leaks but little smoke and easy starting.
Change oil and filters at 100 hr 22 its per engine with a Reverso pump
I named the old girls Faith and Charity !