Removing flathead head studs........

John Kennedy

John Kennedy

Senior Member
Got some out, fairly easy so far. You guys reusing them, or going new? Dumb question, I assume a new stud kit is available and decently priced.

I'm just prepping the block for the molasses bath.
Thanks!
 
I save the old ones... I bought a set of Dorman studs listed for Ford, they didn't have the tight fit in the block... So I reused the ones I had. Roy the Bolt Guy (forgot name) may have something- A set will run around $100 or a bit more... Karl
 
Don't leave your block in that molasses too long. Someone on here did that and posted a picture of their otherwise nice block all full of tinny pits in the gasket areas. I have heard that Henry's studs had special threads or a slight taper on the threads to help seal those that thread directly into the water jacket. I have also heard that some studs made by the well known repro manufacturers do not have the correct threads that go into the block. I reuse original studs if they are in good condition. Some may say this is a no no but I have not had a problem so far doing this.
 
John Kennedy said:
Got some out, fairly easy so far. You guys reusing them, or going new? Dumb question, I assume a new stud kit is available and decently priced.
Click to expand...

I just rebuilt my Merc "99" and reused all the old studs except a couple that had corrosion. I got the 2 replacement studs from Mac's and the fit was very good. Not quite as tight as the original studs, but certainly not a loose fit. One thing you don't want to do is run a tap through the holes to clean them. I use a 7/16 bolt with a flat area cut down the side of the threads to clean the holes, and sealed the threads with Permatex #2.

Bob
 
This is a good time to bring up the discussion of "rope" threads versus cut threads. I am sure someone out there can enlighten us better than I can on this subject.
 
I would reconsider using the molasses bath for a cast iron block.I put some heads in mine and when I got them out they were pitted.I don't think the machined surfaces in cast iron comes out too well most of the time.
 
How bad are the pits? If I pull it out and check it every so often I think I'd be OK? This is an unmachined block, wouldn't any pitting be minor and come out with a .010 bore and valve job?
My main concern is finding cracks and cleaning out water jackets.
 
John Kennedy said:
How bad are the pits? If I pull it out and check it every so often I think I'd be OK? This is an unmachined block, wouldn't any pitting be minor and come out with a .010 bore and valve job?
My main concern is finding cracks and cleaning out water jackets.
Click to expand...

The heads I had in the vat were Y-block Ford. The pits affected every one of the machined surfaces. Most were about the size of the head of a pin but some were deeper.They were all over the machined surfaces,but I think about a .010 surface grind would remove them. Just check them pretty often. I left mine in about 3 weeks.
 
Some studs have rolled threads, with these the threads are actually bigger in diameter than the shank of the stud. Fords used cut threads where the shank has a bigger diameter than the threads. Rolled thread studs dont seal into the block well at all.
 
BillM is absolutely right. It's the class of fit specified when the studs are made that determines how tight they are. Class 1 (the loosest) is a fit you can tighten with your fingers. Class 5 (the tightest) has to be wrenched all the way. JM mentioned in an earlier post on this thread that some Ford stud threads were rumored to be tapered. That type of thread is fairly common on studs screwed into pressure vessels - like boilers, etc. Usually they are Class 5 and are steam tight when installed properly.
 
As for removing the studs, try soaking them in the 50/50 mix for a few days. Unfortunately, nobody makes "Ford" studs, especially longer ones for thicker heads. I did use studs on my Hydro engine and the Bville engine. I would never do that again.
24 bolts torqued to 50 ft/lbs have a clamping force of 1200 lbs. A blown 392 Hemi has 10 studs torqued to #100 lbs which is onlu 1000 lbs of clamping force. Makes you think alittle.
 
Based on the ones I've seen / used, one end of the stud will have the tapered (slightly) thread and the other end will have a straight thread, probably a Class 3 fit. The tapered end is installed into the pressure vessel and the straight thread is used to attach whatever is being fastened thereto.
 
I was planning on reusing my studs. I have a simple question though. The orientation of the head bolts is specific to how they came out, or not? I left the studs on one head exactly as they were taken out, however the other head had some studs fall out of it.
 
I noticed on mine all the short ones were in line along the exhaust manifolds. There's two medium ones, the rest are tall and equal length.
 
Ol' Ron said:
As for removing the studs, try soaking them in the 50/50 mix for a few days. Unfortunately, nobody makes "Ford" studs, especially longer ones for thicker heads. I did use studs on my Hydro engine and the Bville engine. I would never do that again.
24 bolts torqued to 50 ft/lbs have a clamping force of 1200 lbs. A blown 392 Hemi has 10 studs torqued to #100 lbs which is onlu 1000 lbs of clamping force. Makes you think alittle.
Click to expand...
Ron are you outta the hospital? Hope so! What do you mean by soaking the studs in a 50/50 mix? A mix of what?

thanks
Geoff
 
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