So I had a piece of 2" diameter by 1/4" thick oilite bronze bushing left over from my steering column, and may have hit on a new way to keep my roller cam from walking. I cut it in half, drilled a 3/8" hole in it, and ran a 2" cap screw through it and the distributor bolt hole, 3/8" x 16 thread. I machined the cut end of the bushing so it's about .002" away from the cam gear, and will ride on the machined side of the gear itself, and not rub the chain. This turns the distributor hold down bolt into a stud. Add some threadlocker to the bolt, a lock nut to the top of the timing cover, and replace the distributor hold down bracket. What do you think? I was never excited about drilling a hole into the front of the timing cover and through the coolant passage, but will this effectively locate the cam? How much pressure does it make if it walks forward? These bushings are really stout, and designed to rub against steel. I couldn't get any pics through the fuel pump hole, but it looked great in there!
Looks like the one end is square to the cover surface. It should not be able to turn. The bolt is locktited in place. That might work. Looks like the bolt could be longer for the dist. hold down.
You may want to try to torque cover down & check cam end play, then torque down water pump and check it again. The water pump long thru bolts draw the cover down some more. Abt .002
I'll do that, but this is all tentative. I'm also considering a steel bracket with a small roller bearing on it, adding a slot to make it adjustable. On this design, the bolt is firmly tightened to the timing cover, so loosening the distributor has no effect on the bumper. I'll build that into the roller bearing idea too.
I know JW used the TA cam bumper with my roller. http://www.taperformance.com/proddetail.asp?prod=TA_ROL150
TA ROL 150D is the correct cam bumper for a 350 roller cam. Or you can drill and tap the block and use the bronze V6 thrust plate, TA VRL100 and machine the end of the cam to fit. This is in my engine.
Don't suppose there's a roller cam yet for the 215/300/340? Art still has some blanks for the late Rover but they need work to drive the distributor/oil pump. Jim
I've always liked the V6 style cam retainer best, but I have a bit of an aversion to drilling more holes in my block. Maybe it's because I've driven a lot of clunkers that leaked everything from everywhere, but if I can make something that's just as robust, but no drilling or modifying, I'll be satisfied. The roller bearing one I'm working on will look more professional, too.
Huh, and here I am trying to reinvent the wheel like a sucker! I may finish the idea I have in my head for academic reasons, I like engineering challenges, but I do prefer simple solutions, as long as there's no excessive wear. Who knows, maybe I'll go belt-and-suspenders with both mine and the 150D designs.