2 replies to this topic

[DeadSquare]

Would a Needle Roller cope with a modified belt driven Cam ?

 

Last week, I helped with a Full Race 1300 mid-season strip and rebuild.

 

The first surprise was lack of oil under the Rocker Cover, followed later by the realisation that the Cam had picked up the front bearing and rotated it in the block.

 

Something at sometime has left the oil passage and lodged in the lubricating groove in the Cam before digging into the bearing, ruining both, but looking at the lobes, the cam would have needed replacing.anyway.

 

Because the block will be recovered by bushing and line boring, it is an opportunity to use an alternative bearing, or would it be, like steel springs, an impairment ?

[Spider]

My short answer here is no, it won't work.

 

You've partly answered is yourself. By fitting a needle roller, especially to the front bearing, all the oil will flow out of that and next to none will get up to the head. It may also excessively allow oil to drain from No. 1 Main on the Crank too. You'd probably need to also fit an inner ring on the cam journal for the needles to roll on so they don't end up eating the journal.

 

There's nothing in the world wrong with the original babbit type bearings.

[Earwax]

For the Cam liner/bearings

 

What is entailed in refurbishing back to spec -   how is the bushing held in place and what material used?  Cheers