Size of threads that hold lock ring in 617 head?

[yuke]

Would any one know the size and pitch of the threads that hold the lock ring in that holds the prechamber down? I would like to know because as I was trying to pull my prechamber out which I never succeeded at I messed some of the upper threads up and now I can't get the lock ring started. So if I knew the thread size I could locate a tap and clean them up. I want to at least salvage the head out of this engine that the prechamber blew down into the cyl. It's a pretty big tap for sure I'm thinking bigger then the inside of the prechamber threads that the injector screws into.

[ThatOne]

Originally Posted by yuke

Would any one know the size and pitch of the threads that hold the lock ring in that holds the prechamber down? I would like to know because as I was trying to pull my prechamber out which I never succeeded at I messed some of the upper threads up and now I can't get the lock ring started. So if I knew the thread size I could locate a tap and clean them up. I want to at least salvage the head out of this engine that the prechamber blew down into the cyl. It's a pretty big tap for sure I'm thinking bigger then the inside of the prechamber threads that the injector screws into.

The OM 617 prechamber lock ring's external thread dimensions are M35 X 1.5

[Diesel911]

Originally Posted by ThatOne

The OM 617 prechamber lock ring's external thread dimensions are M35 X 1.5

Thanks I put that in my notes

[Diesel911]

On eBay:（1pcs） 35mm x 1.5 Metric Taper and Plug Tap M35 x 1.5 mm superior quality （S)

$22.99+$5.80 mailed direct from china.

I have bought direct from before from different sellers and had no issues. However, it can take like 2-3 weeks to get the item.

A place I have done business with in the US is Victor Machine on the east coast.

Read the Ads closely because M35 is also an alloy of Cobalt when you see that be sure besure if it is the tread size or not.

[yuke]

Thanks guys I was gonna buy a whole set for $60 not sure if it has a tap that big 35 x 1.5.

[ThatOne]

Originally Posted by yuke

Thanks guys I was gonna buy a whole set for $60 not sure if it has a tap that big 35 x 1.5.

But how are you going to salvage the cylinder head if you haven't been able to get the damaged prechamber out?

It looks like that one big ChiCom tap will cost half as much a an entire ChiCom tap and die set!

If you had to go American a cheap one might have cost $75 or a $100! I'll bet you'll be the only one in the neighborhood to have one!