motors

[hauss]

I have a 351 stroker motor with forged crank H-beam rods billet caps roller rockers and keep a close eye on maintainence .I have close to 600 hp <I am told> It is a 427 man o war block rated for 1000 hp. I do see 6500 rpm quite a lot that is where the limiter is set. Given these facts how many miles should I expect to see out of this motor.

[t walgamuth]

I have no idea. I will just say my machinist told me that most engine failures are from the rod cap bolts, so get the best you can there.

[Gaz64]

Depends on the camshaft type (roller or flat tappet), lifter type (hydraulic or solid), bearing manufacturer etc.
Oil pump driven gear type (on distributor) and inspection is also a factor.

Carbon buildup, ring gaps increasing, bores wearing etc add up to efficiency loss.

When you feel the power is down a bit, a "freshen up" is probably due.

Gary

[olddog]

High rpms is what stretches rod bolts. They only stretch when the forces from RPMs exceed the stretch from torqing the bolts down. If you put in good quality bolts and limit the rpm to where the bolts are not getting stretched, then they will last forever in engine life times.

High lift cams and the geometry of all those parts with heavy springs can shorten life a bunch.

A mild build could last as long as a factory engine. The more radical the build and the harder it is ran the shorter the life. Obviously a top Fuel dragster is done in a 1/4 mile. You should be somewhere between and closer to a factory engine than a top fuel engine.

[hauss]

I would like to hear what people are experiencing .All bolts in motor are arp

[twobjshelbys]

Don't expect miracles. Remember the 60's and 70's. My mom and dad got a new car every three years because they just started to leak and smoke. 35-40K miles was magic then. My own 73 Chevelle needed an engine rebuild after about 36000 miles. When they say "they don't build 'em like that any more" that's one reason we ought to be thankful that technology has improved. New machining gives much better tolerances. Even newly machined engines don't seem immune - you don't hear anyone here saying they put a aluminum block 427 in a car and have 200000 trouble free miles.

[Gaz64]

Originally Posted by hauss

I would like to hear what people are experiencing .All bolts in motor are arp

A few have given mechanical experience.

Nobody has a crystal ball.

6500 in every gear continuously, about 500 miles.

A street car, about 50000 miles on a good day.

The price you pay for performance.

Gary

[patrickt]

Originally Posted by hauss

I would like to hear what people are experiencing .All bolts in motor are arp

Around here, the owners are dying faster than the engines.

[1795]

I agree with Gary. If you are running it up to 6500 rpms on a regular basis, like a person would in a race car, then 500 miles is not out of line. Most racers are refreshing their engines every 2-3 years, and those engines probably have only a few hundred miles on them if that. People with deep pockets will refresh them every year and sometimes more than once per year. Running it that hard puts a lot of stress on the engine.

If you are only hitting 6500 rpms every now and then, it should last much longer.

[hauss]

Thank you for your replies all. For some reason I was hoping for 50k . I thought 6500 was pretty safe on a well built motor.

[t walgamuth]

That may be reasonable to think.

[hauss]

Maybe I should explain better, what I meant was hitting the 6500 rpm, but only for a second or two. Mostly 3000 to 4500. Motor seems to love 3000 rpm, that is it"s sweet spot to run all day.

[66AC]

With my typical use of the motor at 2500 - 3000 RPM my 428 FE engine has lasted quite a long time. My engine builder told me that as the horse power goes up the engine becomes more "brittle" and susceptible to wear. Letting the engine warm up before going nuts with the RPM is also a good idea especially in those climates where the entire drive train is cold soaked.

However, recently I did refresh the engine block, crank, rods, pistons, lifters, rockers and heads including distributor, oil pump, water pump, manifold and carb. Could not be happier. The original build was from 1992.

[hauss]

Originally Posted by 66AC

With my typical use of the motor at 2500 - 3000 RPM my 428 FE engine has lasted quite a long time. My engine builder told me that as the horse power goes up the engine becomes more "brittle" and susceptible to wear. Letting the engine warm up before going nuts with the RPM is also a good idea especially in those climates where the entire drive train is cold soaked.

However, recently I did refresh the engine block, crank, rods, pistons, lifters, rockers and heads including distributor, oil pump, water pump, manifold and carb. Could not be happier. The original build was from 1992.

What did the components look like? Wear on pistons cylinders bearings and such?

[1795]

Originally Posted by hauss

Maybe I should explain better, what I meant was hitting the 6500 rpm, but only for a second or two. Mostly 3000 to 4500. Motor seems to love 3000 rpm, that is it"s sweet spot to run all day.

Well, then that is a whole different story. An occasional helps clean out the cobwebs and is not of a major concern as long as you are checking the engine on a regular basis. It's the extended time at high rpms that starts to wear an engine down. Running at about 3,000 rpms is a nice range.

[66AC]

Originally Posted by hauss

What did the components look like? Wear on pistons cylinders bearings and such?

The actual reason the motor was rebuilt was due to an abnormal amount of wear on the woodruff key slot on the crank. The key, over time somehow was worn allowing the toothed gear for the timing chain to wander. This key eventually broke causing a backfire and the timing to go off. A few valves kissed the piston surfaces. So the forensics were that a shroud which holds the key in place was really never good and allowed the key to wander out a bit. The key became battered somewhat. The wear on the engine was minimal especially the bores. The engine builder mildly honed the bores. All new parts were fitted in the rotating assembly and as described. Essentially now the motor is fresh and runs really well so far. With the miles I put on the engine per year (est. 3000 yearly) it was actually in very fine shape after 26 years of use. My clutch plate was also replaced with a Centerforce and also the flywheel was replaced at the same time.

[Gaz64]

Originally Posted by 66AC

The actual reason the motor was rebuilt was due to an abnormal amount of wear on the woodruff key slot on the crank. The key, over time somehow was worn allowing the toothed gear for the timing chain to wander. This key eventually broke causing a backfire and the timing to go off. A few valves kissed the piston surfaces. So the forensics were that a shroud which holds the key in place was really never good and allowed the key to wander out a bit. The key became battered somewhat. The wear on the engine was minimal especially the bores. The engine builder mildly honed the bores. All new parts were fitted in the rotating assembly and as described. Essentially now the motor is fresh and runs really well so far. With the miles I put on the engine per year (est. 3000 yearly) it was actually in very fine shape after 26 years of use. My clutch plate was also replaced with a Centerforce and also the flywheel was replaced at the same time.

Incorrectly torqued balancer bolt, or a replacement bolt that is too long are causes of this. The torque of the balancer bolt is the drive, not the keyway. Keyways and dowels are for assembly.
A friend of mine went down this route, including telling me my timing light was faulty. Checking for true TDC in car revealed the balancer was out.
Removal showed the key chewing up the balancer. Aftermarket ARP bolt was wrong for the engine.
Gary