Thursday, March 10, 2016

Ural Engine Assembly - 5

Jed came by this morning to help with assembly. After struggling with the timing gears both on the cam and the crank, I finally broke down and we went to pick up a made-in-China hydraulic press. It helped immensely and made very short work of both. We removed the cam from the block and a minute later, the timing gear was seated on the new cam right up against the bearing. We then moved the whole engine over and pressed the timing gear onto the crank in very short order. The rear snap ring that was causing me to scratch my head yesterday went in quickly using old bearing pieces and the flywheel nut pulling on the crank. Assembly lube was used on the cam lobes and the rear cam bearing got some fresh oil.

Then came time to install the piston rings and put the rings into the cylinder. After struggling with my old ratcheting band style ring compressor, I tried just putting the piston into the cylinder by hand and squeezing each ring with my fingers. Surprisingly, that worked and the pistons and rings were installed in under a minute. No special tool needed. The bottom of the cylinder is beveled and it was very easy to slip the rings in one at a time while holding the piston. I them installed one wrist pin snap ring into the piston and greased the wrist pin with more assembly lube. The pushrod tube seals were the next thing to go on.

This reminded me that I needed to install the lifters before putting on the cylinder. More assembly lube went on the face of the lifters. Assembly lube is a moly mixed with oil and provides lubrication during the initial startup of the engine before oil starts to circulate. BTW, we did test the oil pump by spinning it (counter clockwise) with a drill with the pump in a pan of oil. The pump works with the flow matching what the YouTube video showed.

I put on blue thread lock onto the lifter screws and screwed them into place. The cylinder was installed and the piston fastened to the rod with the new wrist pin that was packaged with the crankshaft. The pistons also came with new wrist pins but Mickey said to use the ones that come with the crankshaft. All this side needs are the push rods and the heads and it's ready to go.

Now time to start cleaning up the right cylinder as that one was replaced last summer. I will be replacing the piston and rings but the cylinder looked like it was in good shape. But it's still kind of grungy. Not just from mud and grime but from the lacquer that was put on the cylinder base gasket. Since the left was replaced the oil passage at the base of the cylinder was nice and clean. There is no oil passage on the right cylinder. Actually the passage is there but there is no oil supply passage to the right cylinder.

I also need to clean up the flywheel before installing to make sure the new clutch plates fit cleanly.


  1. No, not a design error. The two cylinders are identical but there is only flow to the left cylinder. From the rotation of the engine, the oil flying off of the big end of the rods would end up on the upper surface of the right cylinder but on the lower surface of the left cylinder. So on the left, there is an path to supply oil to the upper surface.

  2. Interesting, what was Mickey's rationale in reusing the wrist pins? Note to self, buy a press....

    1. Brand new wrist pins came with both pistons and the crankshaft. He said that the ones packaged with the new crankshaft are guaranteed to be the right size.

      Buy a press but be careful on what you use it on.