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Cal-look/High Performance => Pure racing => Topic started by: flatfire on April 29, 2010, 20:06:53 pm



Title: Clevite bearing question
Post by: flatfire on April 29, 2010, 20:06:53 pm
Hi Guys i have been searching for information on clevite bearing life spans.

We have had 27 runs on a high compression n/a motor running regular mid 11 sec 1/4s. We have calculated that the engine has been run hard for 5 minutes and has been run on the street for an hour.
What sort of life span would you expect from a clevite chevy big end bearing?

Cheers
Peter


Title: Re: Clevite bearing question
Post by: Mike Lawless on April 30, 2010, 00:57:57 am
I'd expect them to last a long long time if the oiling system is up to the task. If it is not, they won't. Simple as that.

I typically put 80 to 100 runs on in a season. mid to low 11s, 8500 rpm, 1900lb car. I recently had my engine apart to change cams, and after a season and a half, the bearings were perfect.

I spent considerable time to get my oiling system where it is now. There was a time when even after 20 runs, they would be shiny, or "alligatored". It's all about the oil. Interrupt the supply and bearings will suffer. It may even show you have good oil pressure all the time. But be aware that compressed air shows up as pressure too!

Solid supply and they last forever because they never touch the crank. That's the way it's supposed to be.
So if you are wiping out bearings, it's most likely not the bearing's fault. It's either poor assembly techniques or lack of oil. Maybe both.


Title: Re: Clevite bearing question
Post by: flatfire on April 30, 2010, 06:09:26 am
Thanks again Mike for your information. :)
I couldn't find any negative info on the clevite bearings.

Cheers
Peter