The lifter bores have the same rust issues as the cylinders. My idea to clean them up was to use a small two stone hone for small wheel cylinders.
The rust is evident in the bore on the left. The bore on the right is how it looks after a couple of goes with the hone and parts solvent. the rest of the lifter gallery is pretty good with the factory casting paint holding on quite well. I will wire brush any rust areas and if anything does peel off when the engine is started it will end up in the filter or the pan.
All 16 lifter bores needed honing and it is not an exciting job! When the honing was done I used a 3/16″ drill to clean out the oiling holes you can see above, that lead into the oil gallery running the length of the block on both sides. I ran the drill down by hand being careful not to break it off in the bore.
Once the lifter bore honing was done I lubricated them and tried each lifter in what will be its final location. I’m keeping the lifters and the cam lined up as it was in the original JT. All the lifters showed a very small amount of play when fitted in the bore.
Again, I’m not sure what the original lifter bore size should be and what the clearance tolerance is. I measured a lifter and got .094″ I locked the caliper and then tried in the lifter bore. It just fitted in. This being a budget project, I will go with this unless someone tells me otherwise. I have built two well used Studie flathead sixes and I didn’t need to use oversize lifters. I did replace the original lifters as I was using new cams. If the wear had been at all bad I would have found low oil pressure problems. Fortunately I didn’t.
Hard to see, but this is the original JT cam. The lobes are shiny but don’t appear to be scuffed or worn. A bit may be worn off the top of the lobes but, I can live with that I think.
Next I fitted the cam. Before that I looked at the cam bearings. I couldn’t see any wear. Only some discolouration. I cleaned them up carefully with a scotch-bright pad and check them with the calipers. I couldn’t find any signs of wear between the up-down and side-to-side measurements. This block was originally cleaned and bored. When I had my sixes bored and cleaned I had the shop install new cam bearings. I believe this is the case here.
I ran the cam into the engine (very carefully) and it seemed very tight with no noticeable play. I don’t have a .001″ feeler gauge but I d have a .0125″ Thin stuff!. I tried to fit it in with the cam but this is as far as it would go without forcing the cam in. Again, unless someone tells me this isn’t OK for a budget engine I’ll just motor on.
Next will be the job of cleaning up the main bearing seats.