Cylinder head bolt thread

[oldelanman]

Can anyone tell me what thread the cylinder head bolts are ? I want to make a couple of guide studs for when I take the head off to do my water pump and I don't have any old head bolts to use.
Many thanks.

[garyeanderson]

7/16 unc (off the top of my head ), Itook 6 photos and none of them are legible. I measured one and it was .425 x 14tpi

I got a good one with 3 more pictures

Gary

[oldelanman]

Thanks a lot Gary, first responder again! I'll see if I've got anything suitable in my box of old hardware.

[promotor]

Main bearing cap bolts are the same thread, although they may be a little short they'll do the job!

[oldelanman]

Thanks for the tip Al. Unfortunately I don't think I've got any old cap bolts either - I'll find something suitable though.

[ericbushby]

Hello Roger,
I did not have any spare bolts either.
I drilled out a spare bolt, turned down the end of a piece of rod and silver soldered it in. A srewdriver slot was sawn into the other end and it worked well and cost nothing.
Sorry but I cannot find them now to post a photo.
Best of luck
Eric in Burnley
1967 S3SE Type 45 (rained off again)

[Hawksfield]

Hi all

I use two lengths of SS tube filed with a taper on one end this slips into the theaded hole and is sufficiant to install the head.
Dia is 9.5mm

[higgyuk]

Can anyone tell me what thread the cylinder head bolts are ? I want to make a couple of guide studs for when I take the head off to do my water pump and I don't have any old head bolts to use.
Many thanks.

are u stateside? higgyuk

[higgyuk]

7/16 unc (off the top of my head ), Itook 6 photos and none of them are legible. I measured one and it was .425 x 14tpi

I got a good one with 3 more pictures

twin cam head bolt pitch and dia.JPG

Gary

gary,
my user name is higgyuk can u tell me how many dollars u pay for a set of headbolts? higgy

[types26/36]

Roger,
I have cut down head bolts.