Bud_Rolofson@nps.gov (Bud Rolofson) wrote...
>The stripped threads for one of the oil pan (sump) bolts, for which I've been
>trying to find a heli-coil (5/16 UNF), is one of the two bolt holes (out of 23
>for the pan) that is located in the front sealing block of the crankcase.
<snip>
>Any suggestions, opinions on a new front sealing block versus a heli-coil fix?
Bud:
This happened to me with the bolts in the aluminum sealing block in a
1500 cc Midget/Spitfire engine. (be careful tightening!) I don't know how
similar this is to the TR-6 block, but from your description it is pretty
similar.
I recommend a "temporary repair" until you later rebuild the engine...
I chose to drill out and tap for next size up (3/8-24, I guess). Then, next
rebuild, we put in a replacement sealing block and went back to the smaller
bolt. This
is much cheaper than the helicoil, allows you to avoid dismantling the complex
seal
(with the two wooden wedges, etc.) in the car, and works fine (but you gotta be
careful with the larger bolt, to prevent it from stripping also--I recommend a
nut driver, not a rachet wrench, to limit the torque--it doesn't have to be
much.
(and most British cars come with a nut driver.) Of course you have to drill a
clearance hole in the pan, too.
There is another type of thread repair, which my machine shop seems to prefer,
over
helicoil, but I can't recall the name.
Good luck,
Ray
-------------------------------------
Ray W. James, P.E., Ph.D.
Texas Transportation Institute
Civil Engineering Department
Texas A&M University
College Station, TX 77843
Phone (409)845-7436; Fax (409)845-3410
E-mail: r-james@tamu.edu
Date: 12/11/98 Time: 8:37:08 AM
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