V8 ARP Stud Torque Numbers

[Davo]

I've been doing my homework again and thought I'd post my list of what torque settings, (in ft lbs), different people have used.

Head studs:
- ARP Instructions: 80 + ARP lube
- Real Steel: 65 + ARP lube
- V8 Developments: 75
- TR Spares: 65
- PhilipA on this forum: three stages - 40-60-80
- AULRO member quoting UK builder: 65-70
- UK V8 forum: 65-70

Mains:
- ARP Instructions: 110 + ARP lube
- Real Steel: 90 + ARP lube
- AULRO member quoting UK builder: 65
- RPi: 90
- Des Hammill: 70-75 okay, 90 too much unless line boring
- UK V8 forum: 80

This should help anyone else who thought the ARP instructions sounded like too much! I'll probably go with 70 on the heads and 75 for the mains.

A really important point is to tighten up in stages, and that the ARP lube has been proven as far more reliable for consistent torque than anything else. It seems to require lower torque as well, probably because it's so slippery.

There is also some talk about backing off and re-torquing. This seems to depend on what your preference is, but it sounds like it's not a bad idea, at least where a head gasket is being squished.

[Pedro_The_Swift]

Handwritten note from TRS,,

mind you this gasket only lasted 2 years.:(:mad::wallbash:
https://www.aulro.com/afvb/images/imported/2014/01/383.jpg

[Hoges]

I got a set of the ARP studs which they developed specifically for the 4.0/4.6 10-bolt head. They recommended 90 ft lbs :eek:
Thanks to advice from this forum I used 65ft lbs (3 stages) with the composite gasket (Elgin). So far so good. A couple experienced aviation engineers thought 90 was way too much and supported 60-70 (max) especially with the Elgin composite gasket which appears to be quite reliable.

Was interesting that when I removed the heads, they were fitted with the original metal gasket! (Thor 4.6 July 1999 build)

[Davo]

Yes, with lots of reading you can see that there have been a few cases of block threads failing with the higher numbers, like 80 or 90.

Pedro, that was your photo I used for reference but I couldn't be bothered re-reading everything again to find it!

[MacMan]

On my 3.9 rebuild I ran Payen tin gaskets (coated with Hylomar spray) on 14 bolt heads, 10 main bolts in standard order in 3 cycles of 25/50/75 ft/lb. Outer bolts done to 10 ft/lb only. All good 6 months/14,000km later.

[Davo]

Hey MacMan, I remember replying to your V8 problems thread last year, but just discovered your engine build thread yesterday with the lovely photos. Good to see it's been running well, at last.

[MacMan]

Thanks Davo.

I have enough "distance" from the horrors of it all that I smile every time I drive it now. I'm even careful about which shoes I wear since some feel like all ankles when I go to heel-and-toe it. :D