Tom M'Guinn

Does anyone know if there is a spec for the install height of factory or Raceware head studs?

I was getting ready to put my head back on, and tried to tighten down my Raceware studs (by hand as per Raceware) and I noticed that the seemingly tight studs range in height from 66 to 72mm above the deck. (Fluid may have gotten under some I imagine.)

I cannot find a spec in the spec book, but may be missing it. Absent a spec, does anyone have their head off with untouched factory studs available for measuring?

jwl

Our spare block with factory studs measures 72-73 mm form the deck to the top of the studs. Chase the threads with a bottom tap and install the Raceware studs with Teflon pipe paste.

Tom M'Guinn

Thanks Jim. I pulled one of the taller studs and confirmed there was oil under them. The Raceware studs seem to be about 66mm from the deck when fully bottomed out (as per Raceware's instructions). I guess the factory studs have a bit more sticking out above the nuts?

Sam Lin

You need to make sure the stud holes are completely clean and dry before installing. Otherwise, it's a good way to crack the block.

Sam

adrial

ARP gave a spec for amount protruding with the head installed and no HG...I dont remember what it was off hand though.

Tom M'Guinn

I just spent some time drying out one of the stud holes. I made a chaser by cutting a grove in an old stud, but it did not do much and suspect I'll be better off getting a real bottoming tap. Anyone have a good source for that?

adrial

I didn't need a bottoming tap when I installed the ARP's, so long as there is no loctite or any crap built up in the bottom of the hole... I wouldn't imagine the raceware's would be very different.

Tom M'Guinn

I'm guessing there is....

in several holes, the studs spin freely until the last few mm's and then get tight. I imagine gunk has built up in the thread below that point.

adrial

I turned the block upside down on the stand and just poked away with something point (in my case a piece of broken metal) and watched all the crap fall out...

Ski

Raceware install with pipe compound as Jim said and they recommend factory height. ARP, protrude the head 17mm - even with this, your going to be about 71-72mm.

Raceware suggest a retorque after the first heat cycle. ARP - install head gasket, torque to 50#, sit overnight, then back off half a turn(180°), back to 50#, then to 65# final torque

Sam Lin

McMaster is your source for a bottoming tap quick.

Sam

Tom M'Guinn

Well, on a whim, I just called raceware. I expected to a receptionist who would dump me into to sales support voicemail after not being able to understand my questions. Instead, the guy who answered the phone was great. When I asked him the install height for Raceware 951 studs, he was able to answer without even looking it up -- 73mm above the deck. He said Raceware nuts are a bit thicker than stock, so the 73mm spec gives you a few mm's higher than stock. He said they have seen variations in the depth of the factory threads, so you can't really expect to install the studs all the way into the holes everytime and get a workable stud height. He also said that the teflon sealer is used solely to keep the stud from turning when being torqued, without creating all the hassles of removing loctited studs. Thought I'd pass that along for the record...

JDeitz951

This is just to confirm what you aleady found out. I remember the height of my factory studs was 2-15/16 inches (2.94"). Multilpy by 25.4 to get millimeters. Around 73 mm. The new studs screwed in way past that, so bottoming out is not the way to go.

Tom M'Guinn

Can someone educate me about teflon pipe sealant. The stuff I have stays soft and acts more like a lubricant than something to keep the studs from turning. Do they make teflon pipe sealant that hardens up? The raceware guy told me the only point of using the stuff was to keep the stud from spinning when torquing the nuts (without the hassles of loctite on removal).