74M35A2
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Probably had an 8.3L or a 250 with two sprinkler boxes.
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915 series trucks are real trucks sport. They dont want a small cam or school bus engine to power them.Probably had an 8.3L or a 250 with two sprinkler boxes.
It's a morphadite. BC3 and 4 mixture. Used a bc4 oil system, step timing control, bc3 aftercooler, conventional cooling instead of low flow cooling like the bc4. These are rated at that power because they are only used part time and not for prime power, long term running, most likely coupled to a 20-30 kw generator end. Boats are rated this way too, recreational boats will have c series, like in your five tons, rated at 750 hp because they are only used part time, not a lot of hours, the Howells will only take it on a 3 hour tour once a month. Commercial, like a fishing boat, will have less power because it is rated as a continuous duty, meaning it will be on the gas steady for hours on end daily. Same parts, just less HP due to the duty cycle.
So Will and Red will a 290 small cam live if I build it up like this 535 hp in a five ton and watch my EGTs?Not just the piston squirters.
The older small cam 855's (like the NHC250) suffered from early cam failures when cranked over 400hp. 200psi of fuel pressure after the pump is reliably all the cam will survive.
Compression ratio varies as well but not by much. Anywhere from 14:1 up to either 14.5:1 or 15:1 (can't remember which), higher compression on the lower powered models. The piston material was different as well. The 250 has a mostly aluminum alloy piston while the higher powered models have a more heat resistant alloy.
For a reliable build the small cam NHC250 is limited to about 300hp ish, maybe 330hp if you really watch the EGT's. This is assuming no internal mods and the truck that hauls.
A big cam 855 block on the other hand, 700-800hp can be built reliable in a truck that hauls often.
A worn out LDT-465 with lots of blowby DRAGGED you around.You guys are a bunch of tool boxes. That 855 will drag me down the street in flames. The rest of yours, I'm not so sure about....
I'd LOVE a 916 and trailer to match. Zero use for it but it would be lots of fun! That or a Dodge Hellcat. 916 and trailer would be cheaper, but the Hellcat would have the "magnet" inside.915 series trucks are real trucks sport. They dont want a small cam or school bus engine to power them.
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They have the new Demon now that is something like 700+hp.I'd LOVE a 916 and trailer to match. Zero use for it but it would be lots of fun! That or a Dodge Hellcat. 916 and trailer would be cheaper, but the Hellcat would have the "magnet" inside.
290 small cam? No it will have a short life if you try to crank it up that high.So Will and Red will a 290 small cam live if I build it up like this 535 hp in a five ton and watch my EGTs?
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Even if it is in a play toy truck? So the problem is wiping out the cam? 20,000 miles? 200,000 miles? And this will be because of excess fuel pressure over 200 psi?290 small cam? No it will have a short life if you try to crank it up that high.
A 290 big cam could be built up to those levels but not a small cam.
Cam itself and possibly the crank bearings at those power levels.Even if it is in a play toy truck? So the problem is wiping out the cam? 20,000 miles? 200,000 miles? And this will be because of excess fuel pressure over 200 psi?
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So Will and Red will a 290 small cam live if I build it up like this 535 hp in a five ton and watch my EGTs?
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So Will what do you think the highest fuel pressure should be on a small cam? 200? 190?
If you ain't using the truck to pull 80k on a regular schedule, 200-210 will be ok, short trips, parades won't hurt it, BUT, higher than specified rail pressure will break cam follower shafts, roller pins and compromise injector lobes in a very short time. And, if you don't catch the failure, the little pieces parts of the failed cam can and will cut through the filter media, ESPECIALLY if the filter is an old style paper media, and go directly into the mains which in turn goes to the rods and before you know it, the bearings have grand canyon deep gouges in them and you loose a bottom end.So Will what do you think the highest fuel pressure should be on a small cam? 200? 190?
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Okay well the 250 won't be NA for long and I don't want to jack the fuel pressure over 200 if I know it will kill the engine, but I am going to beat on the engine without mercy and I expect it to fail at some point.If you ain't using the truck to pull 80k on a regular schedule, 200-210 will be ok, short trips, parades won't hurt it, BUT, higher than specified rail pressure will break cam follower shafts, roller pins and compromise injector lobes in a very short time. And, if you don't catch the failure, the little pieces parts of the failed cam can and will cut through the filter media, ESPECIALLY if the filter is an old style paper media, and go directly into the mains which in turn goes to the rods and before you know it, the bearings have grand canyon deep gouges in them and you loose a bottom end.
WHY do you need more fuel pressure? Accelerate a bit faster, it won't be that much faster. More pulling power? It is a NA, 855cid engine, it will only do so much without being force fed the air needed to make better, usable, reliable power. All the black smoke out the pipe is just wasted dollars.
But it's YOUR stuff, do what you feel you need/want to doJust sayin'