Ready for the top work

The engine is now ready for its valves. That will happen another day!

Re-assembly: The Heart

Here is the new piston with the rings installed. The picture is blurry, and that's appropriate because that's how my mind felt after trying to interpret the Chinglish installation instructions that came with the ring kit. Yikes! The Kohler manual, unfortunately, doesn't address these details as the rings come in such a wide variety in the "service" form. I think I got it right. I hope I got it right. Nothing good will happen if I didn't.



Here is the rod mated with the piston. Nice and shiny.




And here I'm using my Princess Auto ring compressor to squeeze the rings down to size so I can fit the piston/rod assembly into the block. The ring compressor is one of the few "special" pieces of equipment I had to purchase for this project. Without it, it would have been nearly impossible to get the piston installed without damaging something. This is one part of the rebuild process where you don't want to cut corners.



Alrighty! Piston and rod are in, and the rod cap (with the long oil dipper you can see here) is torqued to spec. I decided to coat the oil pan gasket surfaces with a gasket compound to ensure it doesnt leak. The machined surfaces were quite a bit rougher than I would have liked (though probably still fine). The compound is just cheap insurance. This is the last time most of us will ever see the inside of this engine, I hope anyway :)

Re-assembly: The Guts

The picture above shows the block with the crank back in, and the camshaft and balance gears also in place. This was one part of the assembly process that I was a bit nervous about because for the engine to run properly (and smoothly) the gears on the crank need to be properly timed (aligned) with the other gears. The last time I rebuilt an engine of this type (about 25 years ago) I recall some stress over this step, but it went fine today. The service manual for this engine is really superb. It was written back in the days when the people who actually designed the engine and built it also either wrote the manuals, or had a hand in them anyway. I had no problems.

At least, no problems with the procedure. I did run into a bit of a snag while torquing down the bearing plate. This is the plate seen to the right of the block in the picture above. It holds one of the main bearings that keeps the crankshaft in place. There is a specific torque spec on the four fasteners that hold this puppy in, and while torquing them down I got them to reach just about spec, then they softened and wouldn't come up. Damn! I first feared that the female threads in the block were giving way - that would have been really bad. I removed the plate and inspected the threads in the block - it was fine. Hum. Maybe a bit of OCD was going on, because I re-assembled the plate the same way and hoped for a better result the next time. Nope. Worse actually, one of the bolts broke. Well that explained what was going on, anyway. I can't quite figure out why the bolts weren't holding, that was a mystery. I noticed a second one was also about to fail. Anyway, I had some stock in the shop and made up four new ones and they torqued up just fine.

There is one gasket under the bearing plate, and a selection of paper spacers as well in the gasket kit - you select the right number of paper spacers to get the correct crank end-play. I happened to guess right with two spacers, giving a crank end-play of about 0.006". Nice and tight.

Painting pics

OK here we go! The picture above is of the block, of course, with the black areas masked off and after the third coat of Cub yellow. Yes, that is a balloon stuffed in there.

The picture below is of the cooling shroud and air cleaner, after three coats of Cub yellow.


In the next pictures the masking has been removed and the important surfaces have been cleaned up with emery cloth. The engine block is now ready for re-assembly. It looks sharp enough that you could almost take this thing out on a date!