ellis838@concentric.net wrote:
> Jarrid,
> I have looked local for a replacement head bolt with no luck. Did a
> search for Aircraft Spruce and looked at their bolts, is the thread
> length long enough? I may not understand how the bolts are measured but
> it looks to me as though the thread length would be short. Stock under
> head length is 4 3/16 and the thread length is 7/8 or there about.. The
> two bolts they list that are close in length are 4 1/8 and 4 1/4 both of
> which have a 7/16 thread length if I am interpreting the spec correctly.
> Which of their listed bolts is the one you were referring to? The two I
> looked at are AN6-41A and AN6-42A. Thanks Jim
Jim,
It is good that you read the spec, this goes more than half the way to
getting
an acceptable fastener for the alpine. I think 7/16 is not right however,
a cheat sheet I have on AN fasteners shows that all 3/8 diam fasteners
have a .640 threaded section. One would presumably measure the head
thickness, and add for the washer thickness such that you dont use all the
.640 when the fastener is fully torqued.
I didnt really feel comfortable with that number of threads on my race
engine and ultimately I opted for 3/8 inch studs, with coarse threads on the
head side. Seems to have worked, but the jury is still out on durability
and the specific torque figures when using the coarse threads.
Jarrid Gross
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