It's my understanding one of the problems they had with the new aluminum flathead engine was getting the head studs to seal and not leak. I'v been told they are useing O rings on the studs between the block and cylinder heads to solve this problem. Have any of you tried this with the original 59 or 8BA?
I read of someone using o rings on the top surface of the head with a washer on top of it; with a bevel or chamfer facing the o ring. This was done to keep leaks from showing on the outside of the heads. I imagine that the same thing could be done by chamfering or counter boring the hole on the bottom of the head, but that would only seal the stud to the head and the gasket would still need to seal the block to head junction. I'm thinking that the hole in the gasket is a snug fit to the stud. I suppose a chamfer could be cut in the block for another o ring but the decks on the original engines are thin anyway so probably not a good idea there.
My only guess as to why they do that is because you have to use antisieze on the steel studs into the alum block. On an orig block you could use a sealant that won't leak.
I may have just found the problem with not getting this engine to stop leaking at the head studs. I've used new Offenhauser head studs, I just miked the outside diameter of an un-used Offy stud and get .426 the used original Ford stud mikes .434. That doesn't sound like much but just may be part of the problem. The new aluminum heads have a lot more clearance around the studs, an O ring under a washer on top of the head sounds like it would be worth trying. Somethings gotta happen at a $ 100.00 a pop for copper gaskets this is done got serious.
I had problems with leaking head studs also. used ARP studs and their sealant. Had a lot of leakers so pulled them one at a time and put permatex on them, that cured some of them some of the time. Ended up using the chamfered washers made by ARP available from Summit in 12 packs and number 013 O rings from the local bearing store no more leaks.
I've been using GM Pipe Sealant with PTFE a teflon based sealer (available at GM dealers ) for the past few years and I swear by it, not at it, it will allow you time to retorque as it does not harden or crack, great stuff IMHO..................... on original Henry stuff alu blocks out of my league.....
The thread fit on the end of the stud that screws into the block (called the tap end) is typically a Class 5 (interference fit) or more commonly a Class 3 fit. The dimensions you show put the Ford stud as a Class 3 and the Offy stud as Class 2. The Offy stud is a little disappointing. Looking at the ARP catalog I couldn't find the fit specified. I guess you have to ask to find out. I ended up using socket head capscrews which are Class 3. Ref: http://www.texthreadinc.com/studs.html Ref: http://www.engineersedge.com/screw_threads_chart.htm
BillM, thanks for that info. Right now I'm going to try the Chamfered ARP washers & 013 Viton O rings that several others seem to have had luck with. Every thing is prepped just waiting on the washers. I am gonna call Dennis Carpenter tomorrow and ask about the 59A studs they sell, if they are class 3 I'm going to get 48 of the long ones, I can make them work & can have them overnight. I'll post the outcome.
OK, no more head stud leaks. Dennis Carpenter did not have any NOS Ford heads, the parts guy I talked to said all their head studs are made in China!! Go figure. I did find NOS head studs for the 59A engine at Early Ford V8 Supply in Piedmont, SC. They have a limited supply & not all lengths. Luckily they had what I could use. Believe me there is a big difference in the thread fit of the Class 3 versus Class 2, with 3 going in much tighter. Used Permatex #2, although I doubt much actually stayed in the threads, installed the ARP champfered washers from Summit & 013 O rings from the local bearing supply, sofar not a hint of a leak. An interesting note: In the search for Class 3 studs I did learn from a local fastner supplier that it is possible to plate class 2 to Class 3 specification for about $100.00 to do 50 lbs of fasterners. Thanks guys for your suggestions and information.
if you have copper head gaskets you can reuse them by heating with acetylene torch,,let them cool and install as long as there are no tears in them.done it many times before after seeing dragracing mechanics do it.arp makes the best thread sealant for studs or bolts that live in water.i used stainless head bolts on my flathead to prevent them from seizing to the iron block and aluminum heads.
Man, I'm glad I'm not the only one with this problem! I guess I'll try the O rings and washers too! What have I got to loose besides more coolant!!!
Leaky head studs are usually caused when a thread tap is run into the stud deck to clean up the threads after the old studs have been removed. This slightly clearances the stud thread and if the new studs are not installed with a thread sealer like Permatex they will weep. Even using NOS studs will not necessarily cure the problem, any stud replacement requires the use of a sealant and if installing aluminum heads the stud bodies should be coated with "neverseize" before the head is installed to prevent oxidation.. Most coolant wicks up around the threads so a quick cure to stop the weeping without disassembling your heads is to pop the radiator cap and warm the engine up, shut off the engine and clean the leaky stud with Brake Klean. After cleaning and take some clear nail polish and paint the stud threads around the head stud nut. This is usually enough to seal the weep with out going thru the trouble of O-rings.
What is the recommended method to install the studs in the block? I was under the impression that studs should be threaded into the block until the threads run out, then backed off half a turn. One of my flathead books also talked abut actually torquing the studs slightly (10ftlbs). What do you guys do?
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