Author Topic: Fitting crankshaft ball bearings (Read 620 times)

charlie · « **on:** August 06, 2006, 03:57:13 AM »

I would like to satisfy my curiosity as to how engine bearings are installed into the crankcase in commercial practice. That is, how is it done in the Nelson or Fox factory?

I have changed bearings in some of my engines and have always heated the cases to expand them, but the way I do it takes me ages to get right, and I am never confident that I have got the heat right. It seems to me that it would be more of a problem if I was doing a hundred or so at a time. Do the factories heat the cases, or somehow assemble them cold?

If heating, what actual temperature is the case raised to?

Thanks in advance

Charlie

Bob Reeves · « **Reply #1 on:** August 06, 2006, 04:46:33 PM »

Never been in a model engine factory but best guess would be a big oven, heat 100 at a time, take them out one at a time, drop in the bearings and on to the next station. It wouldn't be too difficult with the proper measuring equipment to determine how hot the oven needs to be, when the bearings will drop in or out that is hot enough.

I use an Unger heat gun to not only heat up cases for bearing replacement but it works well for removing the back end of commercial fuel tanks. Much easier to control the amount of heat applied than a torch. Also the heat is not as concentrated as it is with a torch. Harbor Freight carries a heat gun that should work but I have no personal experience with the HF version.

Just don't try to use these heat guns for plastic covering, they are designed to shrink heat shrink tubing on low and melt solder on high.

Author Topic: Fitting crankshaft ball bearings (Read 620 times)

charlie

Fitting crankshaft ball bearings

Bob Reeves

Re: Fitting crankshaft ball bearings