ARP Head bolts

[92awddsm]

One more question about the torque, I was talking to the guy from ARP again today to order new nuts with smaller flanges on them and i asked him how much i should torque it to since the package say "The torque values represented here intended to be for general information, not for specific installations". I gave him my part number of the 1g 12mm head studs (207-4201) and he said to torque it to 75lbs. I know i kinda already asked this earlier in the thread, but shouldn't i torque it to the 75lbs thats application recomended even though the box said 86lbs? Let me know some oppinions please, what have other people done in the past for torque on a 1g ARP?

Go by what was written on the paper that came in the box of studs. That is application specific and should be followed.

However, if tightening to ARP's recommended torque specs will hold tight to pressures well beyond what even the largest DSM turbos can produce then I see no point in exceeding those specs.

I have ran in excess of 30psi with a cometic hp hg with arp's torqued to their spec and have had no issues. This is with a 60-1 and a minimum of 25psi on pump gas. I also have not had my head off for over a year.

 

[romeen]

Go by what was written on the paper that came in the box of studs. That is application specific and should be followed.



I have ran in excess of 30psi with a cometic hp hg with arp's torqued to their spec and have had no issues. This is with a 60-1 and a minimum of 25psi on pump gas. I also have not had my head off for over a year.

Case in point.

 

[SFRacingGST]

so then 80 lbs will do fine then?

 

[romeen]

so then 80 lbs will do fine then?

If the packaging that the studs came in recommends 86, then I would stick with that as Keith suggested. No more, no less.

 

[turbo addict]

just posting what I have experience with and if that is what the box says it should be fine, I have mine to the 105 w/molylube along with the other motors we have put together, and like I posted earlier I run 32-35psi on the stock (not-mls) head gasket, and have had the boost line come off and pegged my 45psi gauge, blew a hole in the coupler but the head gasket held. Another thing is the only people locally that had problems were torqued to factory spec, however I was not there when they put their motors together so could also be improper install or procedure. (!Just my personal experience!)

 

[romeen]

just posting what I have experience with and if that is what the box says it should be fine, I have mine to the 105 w/molylube along with the other motors we have put together, and like I posted earlier I run 32-35psi on the stock (not-mls) head gasket, and have had the boost line come off and pegged my 45psi gauge, blew a hole in the coupler but the head gasket held. Another thing is the only people locally that had problems were torqued to factory spec, however I was not there when they put their motors together so could also be improper install or procedure. (!Just my personal experience!)

I guess the question that no one can say for certain is whether or not your exact same setup running the same high boost would have held up had you only torqued the studs to the lower, recommended level.

Nonetheless it is good info and encouraging to me since I would like to upgrade to ARP's but continue using a stock (composite) HG.

 

[krummel21]

Brining this from the dead, If I blew my headgasket would that stretch the ARPs? How can I go about checking if they are OK are not? Measurement?

Thanks in advance

 

[Tanro]

Arps are not TTY. But you should measure them for stretch before you reinstall them.

Lots of OEM headbolts are TTY which means Torque to Yield. That means you torque them to point where they stretch, and if your torque them more, or again they can break.

Generally you use a mirco meter and check the length. Make sure all of them are within say 3-5 ten thousandths of each other.

They should also be close to the orginal manufacturer spec.

 

[99gst_racer]

There's only one way you're going to be able to determine if your head bolts are permanently stretched or not. You would have had to measure them when they were brand new, and record the lengths of each stud. Then, measure again after usage and compare the measurements. They have to match exactly, or they're junk.

But if you didn't measure them prior, then there's no way to know if they're stretched now...
And there's definitely no way to accurately identify stretch by comparing the lengths of each.