What size stud holes in Stag heads?

[mole42]

So, here's a thing. According to "Automobile Engineer" in July 1970 p:283, when writing about the inclined studs used to retain the cylinder heads - "the clearance between the studs and reamed holes in the head is 0.010-0.019in."

I measured a new stud today at 0.433 inches (apologies to you young 'uns, but the Stag is an imperial car...) so the reamed stud holes should be 0.443-0.452. The bolt holes are larger than 0.500in, the stud holes have difficulty accepting a stud to slip through, I haven't yet found a suitable reamer in my collection to try at the specified size.

Has anyone used a correct size reamer to make sure the stud holes are sized according to specification? The ones in my heads seem to be too small.....

Richard

[marshman]

When I did my heads a few years back I ran a 11.5mm drill through the holes. (11.5mm = 0.453"). Did this to clean the holes out and make sure there was clearance. Coated the studs with copperslip on reassembly. When I had the heads off more recently all the studs came out easily.

Roger

[Motorsport Micky]

When I did my heads a few years back I ran a 11.5mm drill through the holes. (11.5mm = 0.453"). Did this to clean the holes out and make sure there was clearance. Coated the studs with copperslip on reassembly. When I had the heads off more recently all the studs came out easily.

Roger

I did the same with a 12mm drill and copperslipped the studs on the shanks also, haven't had it apart since 15 years and over 15k passed.

Micky

[stag8manod]

I did similar to Alan and Mickey to my heads but I used a Nickel anti-seize grease on new nickel plated studs and bolts. About 8 years ago, They haven't been off since.
Cheers Ian A

[elvimto]

I reamed the holes out but I also made four dummy bolts which are body fit so that when I fitted the head I used them where the bolts go to line up the head, They are like studs with a screw driver slot cut into them and they go into the block just finger tight then I fitted the gasket and then the head then all the studs and three bolts and snugged them up then removed the guide studs and then the remaining two bolts. Repeat this on the other head and then proceed with the inlet manifold etc. I did a dry run with the old cleaned gasket and made sure every thing fitted and it worked out for me.