Big Block Gear Drive On A Slant?
It was originally a two idler gear set for a 440. I had it all mocked up as a two idler set and I just bet there was at least 5 or 6 degrees of slop going back and forth with the crank. So I took one of the idler gears out, filed down the front of the block where it needed to go perfectly flat. Next I located the single idler gear between the crank and cam gears and jacked it all together with a small ratchet strap. Next, I made a 3/8" OD x 5/16" ID sleeve and slid it into the gear pinion. I previously drilled a 3/8" hole dead center all the way through the pinion so I could bolt the whole shebang right to the front of the block. Before I tightened the ratchet strap tight, I folded a standard piece of printer paper folded it in half and put a piece between the cam and idler and another between the cam and idler for clearance. Then I jacked it tight together, slid the sleeve into the pinion as a drill guide and drilled a 5/16" hole right through the front of the block into the crankcase. Then I tapped it to 3/8 x 16 so I could bolt the whole thing right to the front of the block. It worked good, as all I have is about .004" slop in the gears. Just right. Here's a shot after I found TDC on the crank and cam and marked the gears with a black sharpie. I'm going to take everything back apart and center punch and use a small drill bit to make some very visible alignment marks on the gears.
