The last time I put it together I used Indian Head sealer, it leaked.
I believe the problem is stud diameter. I have tried the studs that were in the engine when I got it, and the ARP studs, both leaked. I pulled it back apart today and measured everything up. The "original" studs measured .560", the ARP measured .560", but the ones I pulled out of my spare engine today measured .563" and fit the threads real tight. I came on this hunch today after looking up other issues with studs leaking. There are 3 classes of studs, 1 which is loose for easy assembly, 2 which is made for strength, and 3 which are made for zero clearance. It looks like the studs in my spare engine are class 3, the ARP are class 2 and the original ones are either class 2 or just cleaned up too much.
The studs that leaked would wiggle until they bottomed, a lot like a bolt that is threaded into a hole. The ones out of my spare engine are tight all the way after the first 2 - 3 turns. I have everything cleaned up, including the closer tolerance studs and will reassemble once I get a head gasket. I will put some 567 sealer on them, per JD Seller and use them. The moral of the story is that be careful that you do not clean up threads too much that must seal and make sure that replacement studs measure the same thread OD, because there are differences.
I believe the problem is stud diameter. I have tried the studs that were in the engine when I got it, and the ARP studs, both leaked. I pulled it back apart today and measured everything up. The "original" studs measured .560", the ARP measured .560", but the ones I pulled out of my spare engine today measured .563" and fit the threads real tight. I came on this hunch today after looking up other issues with studs leaking. There are 3 classes of studs, 1 which is loose for easy assembly, 2 which is made for strength, and 3 which are made for zero clearance. It looks like the studs in my spare engine are class 3, the ARP are class 2 and the original ones are either class 2 or just cleaned up too much.
The studs that leaked would wiggle until they bottomed, a lot like a bolt that is threaded into a hole. The ones out of my spare engine are tight all the way after the first 2 - 3 turns. I have everything cleaned up, including the closer tolerance studs and will reassemble once I get a head gasket. I will put some 567 sealer on them, per JD Seller and use them. The moral of the story is that be careful that you do not clean up threads too much that must seal and make sure that replacement studs measure the same thread OD, because there are differences.
