Doris's engine (1960 Dominator 99) has been dismantled for inspection. Both camshaft bushes have been installed with the oil holes out of line. The camshaft bearing area surfaces are scrolled and Roy Bacon appears to suggest that the combination is acceptable. When dismantling there was plenty of oil in the trough and at either end of the camshaft; indeed the breather disc was tricky to remove being stuck in the oil film.
What do the expert owners think please? Is this folly or was there method in the previous builder's apparent madness?
Every NHT up to and including 20M3S have the thick wall cam bushes. The thick wall bushes have a thin clearance groove around the OD of the bush and therefore negates the need for hole alignment as it IS required for all 200000 and 300000 thin wall bush engines.
Thanks David, much appreciated.
The evidence for Dominator engine rebuilds is that when good quality bushes are fitted then lining up the oil holes is not too critical. What I would suggest you check......is the alignment of these bushes with each other. The last time I rebuilt a Model 7 engine with new camshaft bushes the camshaft began to bind when turned. I wasn't too surprised as there is bound to be some metal movement in the crankcases after 70 years of use. I often find the same issue with new valve guides. It doesn't seem to matter how good modern CNC machining is....... the slightest warpage/distortion will mess up what were previously perfect lines.
The bushes are in good nick and do not require replacing and the cam was running smoothly on strip down so that is one less thing to worry about.
If the correct bushes were used by the PO, and this appears to be the case, there will be an oil groove around the outer circumference of the bush which makes perfect alignment of the holes less necessary . Your earlier findings concerning lubricant in the housing and the way the cam was rotating would seem to confirm this.