Rb25 head stud thread height

[stove]

Hey guys, 

 

I am re-assembling my head and I noticed when removing the arp head studs, a couple of the nuts had bottomed out on the thread. i was wondering if anyone knew the height required for the threads to not bottom out. 
 

From my measurements;

-Block face to nut 70mm (both wound in

all the way by hand) 

-Washer 3mm

-Factory head gasket 1mm

so this means if the height of the cylinder head face to the washer face Is less than 66mm the nut is not actually compressing the head down. Factoring in machining of the head I know there will be differences but does anyone know the factory height of the head? If it’s something much lower like 65 then I know it was just the stud not wound in properly but just want to make sure I’m getting proper torque as I have read some people double up on the washers 

 

 

[admS15]

Is this on a 25 or 30 block. I've heard of guys using double washers on 25/30 conversions but not on a standard 25.

[Rusty Nuts]

As its only a couple of studs are you absolutely sure there is no crap down the stud holes preventing you winding them right in?

[KiwiRS4T]

You need to run a bottoming tap (apparently Aussies call them plug taps) to clean up the hole. There are special taps called chasers but a carefully used normal tap will do. Maybe use a vernier to compare the depth of the stud holes.

[Rusty Nuts]

1 hour ago, KiwiRS4T said:

(apparently Aussies call them plug taps)

Acually we Don't. Plug taps have a 5 thread chamfer and bottoming taps have a 1.5 thread chamfer.

Edited March 21, 2020 by Rusty Nuts

[Rusty Nuts]

And we call these esky's, Not Chully Buns.