Stripped headbolt, help
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 2,748
Likes: 375
From: South Florida FL
Stripped headbolt, help
Yea, cleaning up the threads to install my ARP Headstuds (234-4110).
I stripped one of the holes. its the rear top one so its not a water passage. So i'm going to helicoil it and hope for the best.
whats the thread pattern for the OEM headbolt. I would figure the ARP would be the same so I can reuse it and not have to go a size up.
I measured the pitch to be 2.0mm but whats the width? M11 or M12? it is metric right?
help plzzzz.
I stripped one of the holes. its the rear top one so its not a water passage. So i'm going to helicoil it and hope for the best.
whats the thread pattern for the OEM headbolt. I would figure the ARP would be the same so I can reuse it and not have to go a size up.
I measured the pitch to be 2.0mm but whats the width? M11 or M12? it is metric right?
help plzzzz.
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
The large holes are M11x2.0
The top row is much smaller. Are you sure you meant a top hole?
Google that thread size, it is somewhat exclusive to Gen3 engines, and there are places that sell insert kits for this thread size.
The top row is much smaller. Are you sure you meant a top hole?
Google that thread size, it is somewhat exclusive to Gen3 engines, and there are places that sell insert kits for this thread size.
Le Mans Master
Joined: Sep 2003
Posts: 6,229
Likes: 202
From: Farmington CT
Cruise-In VII Veteran
what are you using to clean the threads? the ARP studs have a finer pitch on the clamping end, as I'm typing this I could see how you may try to insert the smaller studs in the top row 'flipped' which leads to the question in your post 'are they the same size'
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
The ARP studs have a hex socket on one end, so I'd think it's pretty obvious the opposite end threads into the block.
Also, my studs fit very tight, and screwed in pretty tough the whole way down...threads in the block were spotlessly clean, but I definitely needed the allen wrench to get them in place, and some of them took a lot of "back and forth" working action to get them to go.
For the OP...are they just going in tight (not necessarily stripped), or are they spinning effortlessly and seemingly never hitting bottom (stripped)?
Also, my studs fit very tight, and screwed in pretty tough the whole way down...threads in the block were spotlessly clean, but I definitely needed the allen wrench to get them in place, and some of them took a lot of "back and forth" working action to get them to go.
For the OP...are they just going in tight (not necessarily stripped), or are they spinning effortlessly and seemingly never hitting bottom (stripped)?
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I cleaned mine thoroughly before putting in my studs. They didn't exactly spin in easily either. I looked in the holes with a boroscope and found that there was some red thread locker or sealant left from the stock bolts that were removed. I didn't want to re-tap the holes so I cleaned as best I could and used an allen wrench to put the studs in. They didn't go in hard, but some wouldn't go in by hand either due to this sealant.
There is a whole section on thread repair in the manual. I think I posted it once before, but if you need it I can get it tonight when I get home from work. Basically though, its just explaining how to heli-coil the block and gives the required sizes.
There is a whole section on thread repair in the manual. I think I posted it once before, but if you need it I can get it tonight when I get home from work. Basically though, its just explaining how to heli-coil the block and gives the required sizes.
