proper length of head bolts for stock heads

[felix37]

Can anyone tell me the proper lengths for head bolts using stock heads?
and should they be grade eight?
Thanks!

[Ray Balukas]

Hook up with Walt Dupont , he'll have the info for you.

[GOSFAST]

Originally Posted by felix37

Can anyone tell me the proper lengths for head bolts using stock heads?
and should they be grade eight?
Thanks!

Hi Felix, not Walt here but the OEM short bolts are 1.940" and the long ones are 2.625".

I would use at least a "Grade-8", this is nominally 150,000# tensile.

We use only ARP fasteners, they are mfd with rolled threads instead of machined (with a cutter) and are rated at 180,000#. We use 65# torque on all our Flatheads with iron heads, 55# (nominal) with aluminum!

(Add) This is pertaining to the 8BA platform.

Thanks, Gary in N.Y.

P.S. For the 1.940" size you could use a 2.000" with no problem. It slight difference wouldn't be that critical.

[joel]

Go here for the studs for 59 and earlier http://www.fordscript.com/ford_bolts/products.html

[oldford2]

The original head bolts on a Mercury EAC appear to have a rolled thread. Not sure but maybe Roy N will weigh in on this. Grade 8 bolts from Fastenal have a thinner head than original ones. Roy's have the thicker heads like original. Not sure if his are rolled or cut.
John

[Ronnie]

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Why reinvent the wheel gr 5 @ 50 lbs is more than enough.

See attached. http://almabolt.com/pages/catalog/bo...oadtensile.htm

The world won't come to an end with gr 5 nor will your flat motor.
This thread went sideways.

R

[scooder]

I though that the stock Ford made originals were/are considerably harder than #8. Certainly snap like a hard one. Anybody done a Rockwell test?
Felix, in my head you've got a 21 stud? 1937 type? If so, stock 8BA bolts will Work in most holes, but their are 4(if I recall correctly, not going out to have a look now,off to bed) in each side that are no match for length on any stock 8BA bolts.
If this is not relevant, move along an pretend I'm not here.
Martin.

[35fordtn]

fordbolts.com

[Walt Dupont--Me.]

If I remember right you are use a 39 24 stud engine. I think there is 3 different length bolts in the heads. The short one on the bottom, long one up top, and 2 middle size ones. If I was using bolts I take a 7/16 bolt with a flat washer with the head on the bench, stick the bolts through the head and hole the head gasket on the head. measure about 1/2in. of thread and mark it. I just go the a fasenall place close to me and but grade 8 bolts, there gold color wit 5/8 head. get grade 8 flathead washers, they make those chrome nut covers 5/8 also. Walt

[felix37]

Walt, That's exactly what I needed to know. Thanks all!

[scooder]

Ok, sorry got the wrong engine.
Martin.

[felix37]

No Problem scooder, seeing my avatar I would have thought the same.