I have 4 Porsche 914 engine manuals plus the factory manual on CD. Think I can find an answer about how much bigger the main bearings should be than the crank journal? I am struggling here.

The only place I am finding it is in the Mitchell Repair system, which lists .002-.0039 for 1, 2 and 3 (except #2 is really not to exceed .0035

What clearances do the builders use, and where is that information derived from? I couldn't find it in Tom Wilson's book last night though I thought I would. Now I am curious. And it isn't as though I am not going to rebuild this extra case I have...

Page 11 of your Haynes manual.
1, 3 = .0016-.0007
2 = .0011 - .0066
4 = .0019 - .0074

Zach

Thanks I saw that I think. I don't have it here but did it say something about "radial play"?

OK, with that said a build carrying 6 thousands clearance, with 3 thou of film on all sides at room temp is OK? Sounds a little, well loose.