At 21:56 00-02-14 -0600, you wrote:
>Here's a detailed question about BOP 215 engine mounts. I have engine
>mounts that have 15/32" holes for the bolts that go into block, but the
>block bolt holes are only 3/8". This leaves 3/32" of slop between the
>engine mount holes and the bolt. Doesn't seem right... Do I have the
>wrong engine mounts? Or is there a bushing that's supposed to go
>between the bolt and the mount? Or it there a special 3/8" bolt that
>has a 15/32" shoulder?
>
>Similarly, the engine mounts have tabs that bolt to the frame, and these
>tabs have slots instead of holes. The slots are 15/32" wide by 11/16"
>long. How are these supposed to work? I expected a hole?
>
>Thanks,
>
>Bill Wessale
>
(1) Ma friend.... you are looking at genuine US of A mass (or mess) auto
production clearance factors. It is (was) assumed the engine would not
move laterally or vertically with respect to these (those) holes on the
mounts. Therefore, ie.. henseforth and furtermore.......
(2) The acceptable mis-alinement of the frame attaching points were also
given thought. Thought that resulted in elongated holes so's it would
all match up given the worst-case (extreme) out of spec conditions of all
parts involved. Sometimes dictated by the physical angle of insertion of
the engine into the frame of that given model on that years assy. line.
(3) Now, if you build it, your mileage may vary...... Sholder bolts are
available. Cosult your local (1st cousin) AeroSpaceExpert. Or one of the
many specialty bolt manufacturers who supply AeroSpace (Expensive) Bolts.
Or, buy yourself a lathe and lop off a few thousands of tube to fill the
space in the mount hole. But really, the engine should not move in that
direction at all. Left side mount is under tension (always) and right
side mount is under compression. But neither are ever in shear to the
attaching bolt. OEM mounts are akin to PuppyPoo. Try to find some of
the Pyly-Graphite types and/or the newer safety mounts that will not
pull apart (on the left side) and let the engine tear out of the frame.
(4) Yea... they might just be the wrong mounts. Or the Mfg. made a big
'Universal' size hole in them. I've seen that many times before. If
you are doing a super-dooper engine rebuild, jig the bare block and drill
out the OEM (aluminum) threads; tap for (and insert) Stainless-Steel type
HeliCoil inserts in the motor mount holes. Use coarse threads only. You
can (depending upon your location) go for Metric at this time if you want.
Cheers,
Mr. Shadow (Ret)
|