Loctite 242 (Med. Strength) on Head Studs, 3.2L Carrera

[Determined]

Hi everyone,

I'm getting ready to put my case back together from a complete rebuild and I have not installed my new ARP head studs. A couple of questions come to mind;

1. Is now a good time to put the head studs on or should I wait till the case is back together with all the internals?

2. I've read on another forum that "blue" loctite is recommended for head studs and applying onto the case and not the stud itself, is Loctite 242 adequate? How much should I put? I've read that these studs can be bottom'd out and then backed out about 1/4 turn, does this sound right?

Thanks for your time and help!

Alex

[Eagledriver]

These studs are put in to a specified depth. I think they stick out 115mm but I'm not sure on this. I use red loctite and believe this is the best for this application. You could probably use blue but why take the chance. You should never have to remove these studs again (expecially ARP).

-Andy

[Determined]

Thanks Andy,

My understanding from reading a few threads is that the stud height is not necessary on ARP or any performance head studs. The logic behind it is that it uses different head nuts and washers versus the barrel nut which requires that specific amount of clearance. I will buy some red loctite and use that instead. Thanks for your time.

Alex

[Porsche84]

Stud length is very important. If they are too long, the stud sticks up into the area that the allen needs in the barrel nut (look at a nut and you'll see what I mean). If it is too short, you don't get full strength on the studs. I believe the stud length is 135 mm on the 3.2. Find this out for sure before you install the studs (I think I found it in Bruce Anderson's book in some obscure place). Then, you should use red Loctite, IMHO. The stud can be removed by heating the thread area of the case if you need to later on.

[88-diamondblue]

Stud length with the ARP, Raceware or Supertec does not matter since they all use 12 point nuts and their own washer as part of the kit. Stock headstuds need to be 135mm to use with the barrel nuts. I believe that you bottom out the ARP head studs. Do a search as I know this has been discussed here before. I would contact ARP for correct installation as each vendor their own instructions on how it's done. I used red loctite on the factory steel studs on my rebuild as Porsche uses the same.

[Determined]

Thank you both for your input, I did do some searches on the engine rebuilding forum and found that stud length was not applicable to ARP or any other after market performance stud. However, there were different opinions on the installation of ARP studs, a few people said bottom them out and a few others said bottom out but back it out a bit. I understand that heat plays a vital role on whether you bottom them out or back them out a bit. Backing them out 1/4 turn so that the threads are not stressed when the case heats up makes sense to me. Thank you all for your input. Oh, I'll go with "red" loctite for sealing.

Best Regards,

Alex