Headstuds

M

m_w92278

Junior Member
Im rebuilding a 1940 24 stud I was able to remove the old studs but I am having issues installing the new ones. The new studs do not seem to go in all the way to the shoulder. I spent the money in the arp kit from reds... anyone have any ideas on what to do?
 
Did you chase the holes and blow them out ? Next I would check the length of the threads compared to the old .
 
When chasing the threads, do not use a tap. Use only a thread chaser, of which you can make one out of a 7/16-USS bolt by grinding vertical grooves along the threads.
I know nothing about ARP fasteners, but I can tell you that I would rather use original NOS Ford studs available through Fred Wilner at SS Obsolete in Faribault MN,
"Barnfind08" on the Fordbarn here.
 
I would use a bottom out tap. A regular tap will leave the bottom threads untouched , where as the bottom out tap has a square end for threading all the way down to the bottom.
Vic
 
The reason for not using a tap is because the original threads are a slight interference fit. Running a tap in these threads will destroy that. The stud threads should not be tap, but only cleaned out with a thread chaser.
 
I would also use a sealant. The one I use is steam pipes. Also snug then up to the base of the stud to help seal the water jacket.. There are also 3 blind holes on each side, two on each end and one in the middle. make sure you don't bottom out in the holes.
Now, I didn't think ARP mad studs for the flathead, the originals had only 8 or 9 threads on the course side.
 
I believe ARP sells several different lenght studs. Different heads require different lengths.
 
If the instructions don't answer your questions, I would call them . When using other ARP studs , not flathead ( no reason too ) they always had a drawing spec sheet if asked .
Check your length compared to your old .
 
The ones I saw had too many threads on the course end and you couldn't
snug them up to the block to help prevent leaking. The course end should have only 8 threads.
 
Being a "direct" dealer for ARP some 21+ years now we've always put together our own ARP Flathead main stud AND head stud kits.

Reason being the variety of heads, iron, aluminum, etc, all use different length fasteners.

Almost ALL the bottom threads for the head studs should be .750" long and even a couple of these need addressing over the heat-crossovers in the Flathead blocks.

We can normally "build" the ARP head stud kits in-house and pass them along for much less than the cost of what most aftermarket retailers charge directly from ARP? This allows us the option of "tailoring" the studs to the chosen heads.

Thanks, Gary in N.Y.

P.S. The ARP's are the only fasteners we really use for most "decent" builds we do now, and not only on the Flatheads. We use the #1 (hard-setting) Permatex on the stud bottoms in the decks. Here's a couple shots of the sealer and the different bottom lengths on the ARP studs. We order these individually and all with the "shorter" bottoms for the Flatheads.
 

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    Head Studs Long-Short Bottoms.JPG
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Did some measuring and it appears the coarse thread side is to long the are about 1 in. I have cleaned all the threads out with brushes and with old head stud with three grooves cut in it. Looks like ol Ron was right. Gary thanks for the info I’ll order the next set from you.
 
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