Thread: ARP Head Studs

Originally Posted by garrycol

Pete how did you come up with this number as I have been going through the same considerations. I had picked on about 70 ft lbs which is similar to your figure but I came up with that number after talking with a few people but none had any confidence on how well it would work.

Cheers

Garry

Mainly from this thread Garry. The other reason for erring on the side of caution is the high kms this engine has done. Whether right or wrong it seems to be a low figure that others have used successfully.

http://www.aulro.com/afvb/technical-...e-numbers.html

Pete

Originally Posted by Pierre

ARP would have recommended the tension for a reason.


Why ignore them and under torque?


Pete

Not sure Pete. From my understanding the early kits are designed for tin gaskets not composites. Perhaps this has something to do with it along with the reduced thread contact due to shorter studs. Most, I'd assume, would use composites now. The later kit is apparently designed for composites and with the longer threads and more contact I would be more confident using a higher torque figure.

Pete

Originally Posted by discopete

Thanks guys. I've decided to go with the 124-4003 kit and torque it to 65 ft lbs which seems to be the figure recommended by many instead of the ARP figure of 80lbs.

Cheers, Pete.

ALARM!!!!!


as you can see,, this is the rec torque setting that came with part--

AND ITS WRONG!!


When the heads were done the first time, this figure was used-- and lasted 4 months.
When BOR built the new one the guy laughed at this figure. He really didnt want to tell me what he used but I sorta figured out north of 90---.
He said he undid one of the studs with his fingers,,, which he meant as a joke about how tight it was,,

Originally Posted by Pedro_The_Swift

ALARM!!!!!


as you can see,, this is the rec torque setting that came with part--

AND ITS WRONG!!


When the heads were done the first time, this figure was used-- and lasted 4 months.
When BOR built the new one the guy laughed at this figure. He really didnt want to tell me what he used but I sorta figured out north of 90---.
He said he undid one of the studs with his fingers,,, which he meant as a joke about how tight it was,,

Thanks Pedro. Are you using the older kit with 10 bolt heads? This is the type of first hand experience I was seeking. Will be reconsidering the torque figures. Be interesting to find out what others have used and if there have been any problems.

Pete

The box had buick 215 on it,, thats all I can remember---

Remember the studs themselves are little more than finger tight (the instructions are clear on what the procedure is on this aspect) however the nut torque setting is 80 ft lbs for the Buick 215 studs and 100 ft lbs for the Rover V8 studs.

As discussed - there is a danger, based on others experience that there is a chance that the studs will pull out at these advised torque settings. No doubt they will hold on new threads on a new block - but maybe not on an older block with weakened threads from previous use where stretch bolts had been used.

Garry

I agree with all you said Garry,,
I am wondering, however, how can they be NEW blocks and require new gaskets?

as far as I can see, you have to take that chance and do them up at least to 90,,
after that--

I have used 90 lbft on all the assembled engines (north of 30 of them) with studs and have not yet had a failure of a composite head gasket. That's why I raised the question earlier in the thread, and I say again - why would ARP specify #$#$#@ lbft and someone with a crayon scribble 65 lbft?


Cheers and all,


Pete