[Bill Meyer]

Freshening an engine that I built 8 yrs ago with 50mm cam bearings. Used INA hk5020's. The engine has about 500 passes. The bearings look good and feel good. Does anyone have any experience with projected longevity ? How can you tell if they are worn or need replacing? Thanks, Bill

[cgeise]

I would get that roller stuff out ASAP -- when they hiccup - total motor failure

[slowbird]

Fwiw i've never pulled mine out and i asked my builder about it. He told me he's never had one fail and not to worry.

[aaronman]

Curt - Tell us more about your experiences as we are always trying to learn. I have 4 different engines from 535-541 all w/ roller cam bearings and range from 800 to 1000hp. We have never had a set of roller cam bearings fail but doesn't mean they won't. I'm guessing these engines have over 3000 passes on them in the past 10 years....

[mgarblik]

Originally Posted by slowbird

Fwiw i've never pulled mine out and i asked my builder about it. He told me he's never had one fail and not to worry.

The only roller cam bearings I have heard of failing were ones that ran dry for whatever reason. A good example of how long they could last would be the OE 3800 GM V-6 engines. They ran needle bearings on one end of that balance shaft from day 1. Even with modest maintenance, they ran 250,000 miles or more with very few failures. I can't remember ever needing to change a roller cam bearing from a pure bearing wear issue. Now if junk gets into the bearing from other engine parts going south, all bets are off.

[hgerhardt]

I've had needle/roller cam bearings in my 428 since 1996, Torrington B-3012 1.875 ID ones, supporting a solid roller in a street/strip setup. I had the engine apart to inspect/freshen after it had run about 5000 miles and the bearings looked perfect so I reused them.

[Mark G]

Originally Posted by cgeise

I would get that roller stuff out ASAP -- when they hiccup - total motor failure

I agree very wise words ..

[Bill Meyer]

Thank you for the responses. It's good to hear there are very few ,if any, reported failures.
For you other two, what kind of cam bearings would you recommend on a 50 or 55 mm cam tunnel?

[slowbird]

I ran durabond 55mm babbitt bearings and with the spring pressures i ran they never looked good. The last season i ran them they looked decent but i primed the engine before each weekend fire up. That seemed to make them happy'ish

[Mark G]

I run a Accusump oil accumulator I have no needle bearings in my motor don't want any. No hp advantage having needle bearing in a race motor that you pull apart every year .Just a good oiling system .Just my 2 cents .. I am 1150 hp on nitrous..

[slowbird]

Originally Posted by Mark G

I run a Accusump oil accumulator I have no needle bearings in my motor don't want any. No hp advantage having needle bearing in a race motor that you pull apart every year .Just a good oiling system .Just my 2 cents .. I am 1150 hp on nitrous..

I have back to back dyno tested roller vs bushed lifters. There is hp in roller.

[Mark G]

Originally Posted by slowbird

I have back to back dyno tested roller vs bushed lifters. There is hp in roller.

Not enough to matter to risk my motor JMO.. If you like it or others great ..But it could bite you in the ass,,

[mgarblik]

Originally Posted by slowbird

I have back to back dyno tested roller vs bushed lifters. There is hp in roller.

I would be very interested in seeing those dyno results if you would be willing to share. The only back to back test I can remember was something like 2.4 HP @ 9000 RPM's on a Pro Stock style engine. So I am not disagreeing with you. Also Jesel, very respected in the valvetrain business, argues the same. They just recently began selling a bushing style lifter because they were losing market share and business to other's who do. But they make it clear they prefer needle bearing designs. I personally don't have an opinion on what is "better", because that's very subjective. It depends on what your specific goals are. If HP above all, and 1 or 2 HP makes a difference between winning and losing, then needle bearings are better. But you better be willing to spend the money on absolute premium needle bearings, US made, German or Japanese. Use the Chinese needle bearings almost everyone in the valvetrain business uses, and if one flat spots, spalls, or fails in some way, your entire engine is junk. That's the gamble you have to take to get every last HP and why a set of Jesel needle bearing lifters are $1600.00.

[Mark G]

Originally Posted by mgarblik

I would be very interested in seeing those dyno results if you would be willing to share. The only back to back test I can remember was something like 2.4 HP @ 9000 RPM's on a Pro Stock style engine. So I am not disagreeing with you. Also Jesel, very respected in the valvetrain business, argues the same. They just recently began selling a bushing style lifter because they were losing market share and business to other's who do. But they make it clear they prefer needle bearing designs. I personally don't have an opinion on what is "better", because that's very subjective. It depends on what your specific goals are. If HP above all, and 1 or 2 HP makes a difference between winning and losing, then needle bearings are better. But you better be willing to spend the money on absolute premium needle bearings, US made, German or Japanese. Use the Chinese needle bearings almost everyone in the valvetrain business uses, and if one flat spots, spalls, or fails in some way, your entire engine is junk. That's the gamble you have to take to get every last HP and why a set of Jesel needle bearing lifters are $1600.00.

Well said ..

[slowbird]

Lifters are one thing they take a lot of abuse but roller cam bearings like this topic is about is whole other deal. Very very little abuse and plenty of splash oiling to keep them happy for a very long time

[mgarblik]

Originally Posted by slowbird

Lifters are one thing they take a lot of abuse but roller cam bearings like this topic is about is whole other deal. Very very little abuse and plenty of splash oiling to keep them happy for a very long time

Yes, I agree. May have gotten a little off track. I have seen plenty of failures of needles in lifters and rocker arms as well. As I mentioned in an earlier post, Other than obvious lack of lubrication, I have never seen a roller cam bearing failure that I can remember.

[Mark G]

Originally Posted by slowbird

Lifters are one thing they take a lot of abuse but roller cam bearings like this topic is about is whole other deal. Very very little abuse and plenty of splash oiling to keep them happy for a very long time

Are you trying to convince yourself LOL