TR2/3/3A Oil hole size for Camshaft bearing

[Joel Lester]

I installed my new cam bearings into my engine block last night after getting back from the machine shop.
I was able to line up the set screw holes perfectly - not on the first try of course! But, after a few tries I got it perfect. On the flip side however the oil holes that feed the camshaft bearing are not exact. The hole is patent for sure and believe me they are not significantly obstructed but that hole is not very big to begin with.

I made sure that the correct bearing went in the correct spot and that the orientation of the bearing was like it is supposed to be. I did a lot of reading and watched a number of videos on this topic before I attempted the procedure. I also read that the oil holes are intentionally small so that more oil will be passed on to where it is needed more - like the crank main bearings and on up to the rocker etc. and the camshaft doesn't need very much oil because the load is not that much.

Just looking for a little reassurance that this will be OK??

Thanks in advance for your input!

Joel

 

[Sarastro]

When I did this a couple years ago, I also noticed that the holes in the bearings did not line up perfectly with those in the block.

As long as the holes are not obstructed, it will be fine. There is very little flow through those holes, so even a relatively small opening won't restrict flow much. It's hard to be quantitative here--as long as you have more than half the hole area open, I'd think you should be OK. Also, if you're careful about chips and burrs, you could run a drill down the oil passage and ream out the holes. I may have done that; just don't remember.

 

[Joel Lester]

Thanks Steve!
Yep - for sure more than half of the hole is open. Honestly I don't know how I could get it more aligned. I suppose I could try to drill some out but that might be more risk than the potential reward as they say...

Joel

 

[JohnnyMead]

Mine didn’t line up perfectly either. worst one maybe 2/3rds open. Seems to work ok.

 

[CJD]

As long as half lines up you should be fine. The cam is very lightly loaded compared to the crank. Of course, if it bothers you, you can use a long bit to drill it open through the oil passage. Just be sure to carefully clean out all the metal chips.