How Much Can It Take??
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Joined: May 2002
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From: Avondale, AZ, used to be seattle, washington
Car: 1978 Chevrolet C10
Engine: 350
Transmission: Turbo 350
How Much Can It Take??
i have a 85 350, .30 over, 2-bolt main, 2-peace rear main seal, stock bottom end,
i was wondering how much abuse can a stock bottom end take, what is the top RPM should i take it to, and how long would it last doing it a few times a week, like 3 times a week. thanks for any info!! i want to know how long it will last until i can buy a forged lightweight bottom end and have the block drilled for a splayed 4-bolt main.
i was wondering how much abuse can a stock bottom end take, what is the top RPM should i take it to, and how long would it last doing it a few times a week, like 3 times a week. thanks for any info!! i want to know how long it will last until i can buy a forged lightweight bottom end and have the block drilled for a splayed 4-bolt main.
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Joined: Jan 2000
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Squeeks,
Since a 350 wasn't a stock engine in an '85 'F' car, it would all depend on where the engine came from. If it were a truck engine, the crankshaft would possibly be a cast nodular iron, which is a little more stable and stronger (or, more accurately, resilient) than a gray iron casting. Similarly, the truck engine would likely have heavier rods, but would also have a larger harmonic balancer and exhaust valve rotators. These would tend to limit RPM a bit, while the better crank would tend to tolerate higher RPM and loading. In either case, you really need to keep the RPM at or under 5,800 with a stock bottom end that has not been balanced. Above that, there is no guaranty that you won't shear the oil film in the bearings from imbalance. While this may not immediately stop the engine, it will damage bearings, and engine life will be severely reduced.
Frankly, any stock engine with stock valve train probably would be making so little power above 5,200 RPM that is would be pointless to push it any further.
Since a 350 wasn't a stock engine in an '85 'F' car, it would all depend on where the engine came from. If it were a truck engine, the crankshaft would possibly be a cast nodular iron, which is a little more stable and stronger (or, more accurately, resilient) than a gray iron casting. Similarly, the truck engine would likely have heavier rods, but would also have a larger harmonic balancer and exhaust valve rotators. These would tend to limit RPM a bit, while the better crank would tend to tolerate higher RPM and loading. In either case, you really need to keep the RPM at or under 5,800 with a stock bottom end that has not been balanced. Above that, there is no guaranty that you won't shear the oil film in the bearings from imbalance. While this may not immediately stop the engine, it will damage bearings, and engine life will be severely reduced.
Frankly, any stock engine with stock valve train probably would be making so little power above 5,200 RPM that is would be pointless to push it any further.