Re: more thoughts about needle bearings
 

We have that spring on one of our engines and they have held up real good. The others have triple manleys or comps. I am thinking about changing the others to the Pac spring. My machine shop guy is a manley and comp dealer so that's why I have been using that spring.

Re: more thoughts about needle bearings
 

The real beauty of that 1.5" spring is that the pocket in the head is smaller, helps you stay away from water.

Re: more thoughts about needle bearings
 

Yup that's why we did it. The 441 chevy head is thin in that area.

Re: more thoughts about needle bearings
 

Back on op: Any other theories on needle bearing lifter failures?

Re: more thoughts about needle bearings
 

Wrong material, bad manufacturing processes and bad quality.

Re: more thoughts about needle bearings
 

Prep is important . The assembly grease that holds the needles in place during assembly , needs to be removed before they are run . I use clean mineral spirits and blow dry . It is important not to allow the rollers to spin when blow drying . I have seen some Technicians spin those parts up to untold rpm while trying to dry them . That is a good way to skid and fail the rollers . After drying , I soak the lifters in clean break-in oil , and spin the wheels by hand to try and drive the oil into the rollers . Seems to work , haven't had a failure yet !

Re: more thoughts about needle bearings
 

I have seen problems with lifters do to excessive lifter bore clearance no one seems to measure lifters and lifter bores just buy them and dump them in LOL

I seen where they have seized in the bore because not enough clearance.

Like I have posted before i have pretty much have gone to all .904 roller lifters in most of my builds and alot of the blocks I prep are machined for .904 and no problems.

No blocks go out the door with out having lifters in hand and lifter bores are honed to fit the lifters.

Had a guy last week where I priced out a Dart Little-M block roller cam bearings, Dry sump ETC. had Comp lifters told him those are to small and would probably need to bush the bores back to standard. He told me they measured .842 my reply was never seen a set of Comp lifters to OEM size yet. He would not send the lifters so I passed on the job and he was pissed at me.

https://www.facebook.com/cncblocks.n...79?pnref=story

Here is a good video on different lifters and bore clearance
https://www.youtube.com/watch?v=SpfOKr3B3FA

Re: more thoughts about needle bearings
 

O A Diameter problem?

Re: more thoughts about needle bearings
 

Sizing from low to high

Look over these threads

http://www.yellowbullet.com/forum/sh...t=lifter+bores

http://www.yellowbullet.com/forum/sh...1631930&page=5