stove Posted March 20, 2020 Share Posted March 20, 2020 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 Link to comment https://www.sau.com.au/forums/topic/479998-rb25-head-stud-thread-height/ Share on other sites More sharing options...
admS15 Posted March 20, 2020 Share Posted March 20, 2020 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. Link to comment https://www.sau.com.au/forums/topic/479998-rb25-head-stud-thread-height/#findComment-7926898 Share on other sites More sharing options...
Rusty Nuts Posted March 21, 2020 Share Posted March 21, 2020 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? Link to comment https://www.sau.com.au/forums/topic/479998-rb25-head-stud-thread-height/#findComment-7926920 Share on other sites More sharing options...
KiwiRS4T Posted March 21, 2020 Share Posted March 21, 2020 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. Link to comment https://www.sau.com.au/forums/topic/479998-rb25-head-stud-thread-height/#findComment-7926923 Share on other sites More sharing options...
Rusty Nuts Posted March 21, 2020 Share Posted March 21, 2020 (edited) 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 Link to comment https://www.sau.com.au/forums/topic/479998-rb25-head-stud-thread-height/#findComment-7926929 Share on other sites More sharing options...
Rusty Nuts Posted March 21, 2020 Share Posted March 21, 2020 And we call these esky's, Not Chully Buns. Link to comment https://www.sau.com.au/forums/topic/479998-rb25-head-stud-thread-height/#findComment-7926931 Share on other sites More sharing options...
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