ES2 main bearings

Previously paul_gooch wrote:

I have trawled through an number of messages on main bearings on this site.

Most seem to be advocating one type or another, and mostly aimed at twins. However none help me so hopefully someone else can.

I have stripped down a 1955 ES2 engine for rebuild, and the main bearings had deceased. They pretty much seized solid and broke up on removal of the crank, when splitting the crankase halves.

So I know I need new mains, and to be honest I don't really care who makes them, or whether to mix them, or any of that stuff, I just need to know how to fit them.

Looking in my parts manual, I need three bearings. Two on the drive side, one on the timing side.

How do you fit two bearings on one side!?

Do I have to drift two races into the crankcase on the drive side, and then two onto the crank?

I am sure it is a simple matter, once you know.

Paul

Paul,

Heat the crankcases in the oven to about 150C. Gives uniform temperature distribution. Have the bearings wrapped in plastic in the freezer a day or two before hand. With gloves remove the drive side crankcase and drop in the ball bearing. It should drop in perfectly if you keep it square. When fully home add the spacer ring and then drop in the roller bearing the same way. There should be no need to even tap the bearing into place. If the bearing doesn't seat square or grabs reheat the crankcases and start again. Timing side is just a single ball bearing.

regards Ian