Does anybody know how far out round can FE engine be before it has to bored out? i have 390 thats 3-5 thousands out of round when checking it with a bore gauge. Its currently bored out to 30 over.
Found this article so far, still looking David. I don't know what over size rings can ya get for one that is already .030 over. Budget 390 FE Engine Build Cylinder Bore Honing Photo 18
That is interesting article. That there block that they are working already 30 over and they honed out to 40 over. I just need to know how out of round can Ford Fe 390 have before having it bored out.
Sorry still looking for exact specs. I'm not much help yet but still looking. I'll put in my two cents. Well .005 is half way to a .040 from a .030 bored over. Consider how much wear has occurred from the original .030 - you said like .003 to .005 Now is that .003 - .005 consistent all the way around or is it at the top and bottom of the cylinder? Like an egg shape looking down from above. If they drove it 100,000 miles and what was worn was .003 - .005 Seems like a lot of wear to me. Still depends of how much oversize from a .030 bored over piston rings can fit on a .030 piston. Cast rings vs Moly rings. If .035 rings are out there you could hone it to .035 that would leave .00250 play all the way around the .030 piston. I think with the limited new FE parts available you may be stuck with the standard .030 piston size you already have and new matched rings for .030 or the next step would be a .040 bore and hone then matched piston and ring set in .040. There may not be a "half size" ring set @ .035 I've seen some egg shaped cylinders before and I've seen huge ridges at the top before. Considering those types of wear what kind of wear have the pistons seen? Like a measurement of the circumference of all the pistons taken at several points.
I've got a book with the specs in it, however, its a hundred miles away and I won't be home until friday at the earliest. If you still need it then, I'll post what I can find.
Go by measurements on reading a camping compass. N to S and E to W is 5 thousands out. NW to SE and NE to SW is 3-4 thousands out. Its mainly in the middle of the cylinder.
