Camshaft bushes

[JoshJ]

Lad’s,

Question for those more knowledgeable, I’m about to install new camshaft bushes to my 350. I obtained the two new bushes from Drags, one of the bushes (Crankcase side) has the slot/groove cut into the bush and the timing cover side does not.
The existing bushes that I removed from the cases were the same, one slotted and the other not.

I was looking at another timing cover that I have and noticed that the timing cover bush has the slot/groove and also a hole in the centre of the groove, this hole aligns with a hole in the cover that allows oil flow into the bush.

So, do I need to be cutting a slot/groove into the new timing cover bush and drilling a hole to align with the lube port or is the bush good to go the way it is - no slot or oil hole.

I’d like to get the slot cut/drilled before reaming so just want to confirm what is required.

Pics below of the second cover I have showing slot and hole.

Cheers

Josh

[paul.jameson]

I doubt it will make much difference either way, unless you intend to do 100,000 miles using full performance. Changing the oil frequently may well be more beneficial.

[JoshJ]

Cheers Paul, will leave new outer bush as it is and as the old one came out.

[Simon.Gardiner]

I have to admit, I drill mine to match the oil hole (and then slot them to help the resulting feed)!

SG

[volker.halbach]

I have two camshafts, and on both the inside journal is more worn than the outside journal. So there is probably more need to worry about the bush in the crankcase. Given that there is serious wear even on the camshaft journals, I would assume that drilling and slotting the bushes is not a complete waste of time.

[Simon.Gardiner]

Just for completeness (or maybe confusion!)
Here are some pics of a NOS timing cover I've got that came from Writers.
No oil hole, and no drilling for one - but the bush does have a groove.
The spares book lists these as being supplied 'with bush, oil delivery pipe, pressure valve and...elbow union'. This one has only got as far as having the bush, so whether the oil-hole would have been drilled if it had been completely finished is anybody's guess (until someone finds one with everything but still no oil hole!)

SG

[JoshJ]

Thanks everyone,

Simon, im going to cut the oil groove and drill the bush for oil. Have you come across any other timing covers that do not have the oil hole drilled or was that just a one off? Im guessing they would have installed the bush and then drilled the hole and finished with reaming?

[BarrieSteel]

Yes I have slightly later timing cover which has no oil hole but only groove.My 49 cover did have oil hole and groove,think did away with hole later on.

[Simon.Gardiner]

My 'early' (1940s and early 1950s) covers have the oil hole and the groove. I seem to remember my '56 cover also having the oil hole but I might be mistaken (it's assembled on the crankcases at the mo' and I'm not taking it off to check - however there's also a chance that I might have drilled it to match the earlier ones, sometime back in the dim and distant past!)

Also, it might look to have a pretty rough finish but the bush is finish-sized (ie the camshaft fits into it with a running clearance).

Meanwhile Barrie seems to have answered the question - the very late covers didn't have the oil hole.

SG

[nevhunter]

You can't ream it IF it already has a slot in it. Nev