Rod & Main Bearing life ?

[Mike Gaines]

If you RULE OUT old oil/filter and or improper installation what life should you expect with your rod and main bearings ?
I change my oil and filter every 30 runs.
What component/feature of your motor build shortens bearing life ?
14 or 15-1 compression ? Is this the biggest culprit ?
RPM
or what ?
My motor has 12.2-1 compression and I shift at 6200 1-2 and 2-3 and go thru lites at 7000rpm.
What should I expect out of my rod and main bearings ?
PS: Nothing is broke, just wanted to start thinking about if I should
be checking my bearings soon.

 

[dvw]

Mine is 15-1, 7200rpm, 5w25 JR1 oil. I change the oil at the start of the season. Roughly 100 passes. Bearings get checked every season. Rods always look like new. Mains about 300 passes.
Doug

 

[66Satellite47]

Back in the day, my 7000+ RPM bracket motors got torn down at 200 - 250 runs. Bearings always came out looking pretty good. The stock 440 steel cranks however would lose the "tuning fork ring" though. An indicator of developing cracks. Never broke one though. I did break a main cap in half. Motor still ran good. That was a low deck 452 13.2 CR that saw 7200 RPM routinely. Bearings looked pretty good, 250 runs. I changed oil every 30-40 runs on all my bracket motors.

 

[jamie]

Aluminum rods or steel? If your filter is clean your bearings are fine with steel rods.Aluminum rods would be more of a concern. I personal would avoid restretching rod bolts/threads every season but that's just me I guess.

 

[Mike Gaines]

Aluminum rods or steel? If your filter is clean your bearings are fine with steel rods.Aluminum rods would be more of a concern. I personal would avoid restretching rod bolts/threads every season but that's just me I guess.

I have the complete Ohio Crankshaft 505" rotating assembly using H-Beam Rods and SRP flat top pistons.

 

[66Satellite47]

Mike, the the good steel rods & crank should hold up to many, many hundred runs with no bearing wear with the RPM you're running.

 

[Challenger340]

If you RULE OUT old oil/filter and or improper installation what life should you expect with your rod and main bearings ?
I change my oil and filter every 30 runs.
What component/feature of your motor build shortens bearing life ?
14 or 15-1 compression ? Is this the biggest culprit ?
RPM
or what ?
My motor has 12.2-1 compression and I shift at 6200 1-2 and 2-3 and go thru lites at 7000rpm.
What should I expect out of my rod and main bearings ?
PS: Nothing is broke, just wanted to start thinking about if I should
be checking my bearings soon.

I still get back Steel Rod 540's/850hp for freshening about every 400-500 pulls that we originally built back in the 1990's, with no discernable Bearing wear whatsoever. I change the Bearings every 2nd freshening(800-1,000 hits) just because.
As long as you have good Vertical Clrc and the Bearing Eccentricity still measures fine with no width increases = good to go.

Bearings only "cool" by the introduction of fresh Oil IN.... and Oil has to be able to get OUT to facilitate that. Vertical Clrc., Crush, and Eccentricity are crucial !

 

[moper]

I'd say seasonally. Better to check and be ok than not to check.