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Well I've recently discovered that GM used a 11mm x 2.0 thread in the block for the head bolts. I was wanting to chase the threads in the block before I install the heads. Does anyone have an alternative to the $60 thread chaser from ARP that I will only use this one time? I do not have any of the old head bolts to make into a thread chaser.
Well I've recently discovered that GM used a 11mm x 2.0 thread in the block for the head bolts. I was wanting to chase the threads in the block before I install the heads. Does anyone have an alternative to the $60 thread chaser from ARP that I will only use this one time? I do not have any of the old head bolts to make into a thread chaser.
All you gotta do is take one of your old head bolts and cut a line down the treads and and that will act as a thread chaser. Then jet blow some compressed air in there to get he debris out.
All you gotta do is take one of your old head bolts and cut a line down the treads and and that will act as a thread chaser. Then jet blow some compressed air in there to get he debris out.
Just get an inexpensive tap and die set and use the appropriate sized tap to chase the threads. Then you also have a tap and die set you can use again and again in the future.
For all the people suggesting using a tap - NO. You NEVER want to run a tap down into a head bolt hole because it will remove too much material and make the thread weaker. If this is an alloy block, kiss that hole goodbye. You need to use a chaser or cut a slot into a factory bolt. These methods remove minimal material and mainly just form the thread back into place. An actual form tap would be ideal for this but M11 is a non-standard thread so I doubt you’ll find one for cheaper than ARP’s chaser.
For all the people suggesting using a tap - NO. You NEVER want to run a tap down into a head bolt hole because it will remove too much material and make the thread weaker. If this is an alloy block, kiss that hole goodbye. You need to use a chaser or cut a slot into a factory bolt. These methods remove minimal material and mainly just form the thread back into place. An actual form tap would be ideal for this but M11 is a non-standard thread so I doubt you’ll find one for cheaper than ARP’s chaser.
Unless the threads in the block are damaged the proper sized tap should not be removing any base material from the block.
That's part of why everyone recommends, and uses, an old head bolt or the ARP tool.
The old head bolt is free, the right length, wont harm the threads etc etc
That's the only answers, it's been explained many times, and people are still asking
Well I've recently discovered that GM used a 11mm x 2.0 thread in the block for the head bolts. I was wanting to chase the threads in the block before I install the heads. Does anyone have an alternative to the $60 thread chaser from ARP that I will only use this one time?
Well, there is a guy on flea bay that's selling a "homemade" looking one that's about $20 bucks less than the ARP one.
You can always resell the good one when your done with it. recoup some of your initial investment...
11-22-2014, 07:27 PM
Thread chaser for head bolt threads 
