Has it really been two months since I touched this thing? Sheesh. Well, in the mean time I completed the annual condition inspection on the plane, solved a very pesky problem with the Mercedes (turned out to be gummed up fuel injectors, of all things), took a vacation in northern MN, and… umm… whatever.
I gotta get something going with this thing. It’s been taking up way too much space for way too long. I was supposed to have this car done and sold six months ago. But it’s awfully easy to put off things I’ve never done.
Tonight, spurred on by the bravery of a good stout Manhattan, I attacked the heads. It all started innocently enough. I had bought a new dial indicator with a magnetic base to check the valve guides for excessive wear. It was still in the case, so I tried it out. Can you believe I made it to 50-nevermindhowmany years old, grew up the son of a professional mechanical engineer who designed semitrailer tank trucks, and have never used a dial indicator? The valve guides are fine, thank goodness… the worst one I found had .005 wobble at the tip of the valve stem, in any direction. That works out to around .0015 clearance, according to Mr. Monroe’s book. I decided to lap the valves, as long as I was out there.
I got all 16 of the new valves lapped; the seats all look quite good now. While I was at it, I decided to finally try out the carbide burrs I bought a couple months back. One cylinder head now has all four of the big lumps removed from the exhaust ports… THAT was easier than I thought it would be. I’d never used a die grinder as a grinder before, either. I’ve used a cutoff wheel… anyway, I’ll finish the cleanup and polishing (to some degree at least) once the other head is done. I figure even if left rough it will be better than having the big restriction in the port… but I’ll clean and polish them up as best I can. I’m pretty happy with the results.
I was on a roll. I heard a tiny voice taunting me. Took me a while to track it down, but it was the Flex-Hone calling me all kinds of names I won’t repeat here. I swear that’s why I pulled it out of the box of stuff from Summit Racing and doused it with oil. I figured shoving it into a cylinder bore would shut it up. The taunting continued until I had beaten it into submission with a Ryobi drill and a number of passes through the cylinder. By the time I was done the cylinder wall looked so nice, I went ahead and did the other seven. No more taunting from that tool, I tell ya! And those cylinder walls look good now, too. 45 degree cross hatch, and a light coating of WD40 to keep them safe for a few days until they get something better. Like another Jet A cleaning, a light coat of oil, and pistons installed.
While I was out there, I pulled the main bearing caps off and dropped them into the can of degreaser, after removing the old bearings. I used some solvent and a brush to clean up the mating and bearing surfaces in the block, then dropped the new bearing halves into the block and set the crankshaft in place. Figured that was enough for one night, so I went in and spent almost as much time trying to scrub all the grease and iron powder off my hands as I did working on the engine.
Tomorrow I’ll pull those main caps out and try out Plastigauge for the first time, too. I measured the bearing journals with a micrometer early on (I HAVE used those before!), so everything should be OK… but Plastigauge is cheap. If I’m not careful, I may actually have this thing back together before the end of summer. Really, the biggest challenge looks like it will be getting the block and heads cleaned up enough to repaint.