Cylinder head bolts in stainless steel no or go

I don't drill and tap a head without my head fixture to keep the head rigid and square. Unfortunately you are so far away. In over 25 years, I have only had to do 2 drill/helicoil jobs on the face of a head.. The fixture comes in most handily for holding heads if CCing . Cylinder head thermal expansion cycles VS bolt stretch is a intriguing subject. :mrgreen:

SteveA said:

comnoz said:

pantah_good said:

I have a question about installing the CNW / ARP head mounting hardware. The three 3/8 studs require modifying the head with 3/8-16 heli-coils. I've done lots of heli coils by drilling for them with a hand held drill and never had a problem. The head looks to me like a difficult item to strap down to a drill press to "properly" tap drill those holes. Should I even be considering drilling those three holes with a hand drill for the heli-coils?

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You can drill the holes with a drill but you need a guide plate to do it. I used to use a 2 inch thick iron plate with a hole drilled through it. Just make sure the hole is straight by boring it in a mill [or precision drill press]

Then I had a second hole that was tapped with the helicoil tap in a mill so it was straight. I used that to guide the tap straight into the head.

Don't even think about doing it by eye. Jim

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Helicoils or Time Serts?


I know the best solution is for you (Jim) to insert your own inserts after CNC work, but I am probably not going to send my head across the Atlantic, so I guess it is helicoil or Time Serts, which should I choose?

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I'm also based on the best side of the pond in Ireland

I did get a head worked on by Jim recently and if I could I would just leave it around so I can admire the engineering work he does so well but it will hopefully be up and running on my Norton in the next 2-3 weeks.

I have another head which just needs the inserts done, I was checking out my options on this side of the pond and this company say they can do brass inserts for the Norton head: http://www.jdautoworx.co.uk

I have no connection with this company nor have I ever used them to do any work for me but I plan on ringing them to talk to the chap about the work he has done.

[quote="click

I'm also based on the best side of the pond in Ireland

I did get a head worked on by Jim recently and if I could I would just leave it around so I can admire the engineering work he does so well but it will hopefully be up and running on my Norton in the next 2-3 weeks.

I have another head which just needs the inserts done, I was checking out my options on this side of the pond and this company say they can do brass inserts for the Norton head: http://www.jdautoworx.co.uk

I have no connection with this company nor have I ever used them to do any work for me but I plan on ringing them to talk to the chap about the work he has done.[/quote]

I've used them lots of times, including all 3 inserts on the bottom of the head. They used to be BLR Engineering. Quality work and no problem recommending them

Seeley920 said:

[quote="click

I'm also based on the best side of the pond in Ireland

I did get a head worked on by Jim recently and if I could I would just leave it around so I can admire the engineering work he does so well but it will hopefully be up and running on my Norton in the next 2-3 weeks.

I have another head which just needs the inserts done, I was checking out my options on this side of the pond and this company say they can do brass inserts for the Norton head: http://www.jdautoworx.co.uk

I have no connection with this company nor have I ever used them to do any work for me but I plan on ringing them to talk to the chap about the work he has done.

Click to expand...

I've used them lots of times, including all 3 inserts on the bottom of the head. They used to be BLR Engineering. Quality work and no problem recommending them[/quote]

Thanks for the feedback, good to know.