17 years, maybe 20 k miles on painted all thread head studs??

[chrismorse]

Hi Guys,

Is it "prudent" to continue using these head studs, or should i be "wise" and go with something like the Supertech studs???

In 2005 my dad had the top end done on his 74 2.7, since there has been 14K, maybe 20K miles, (funky odometer). Inserts were done back in 82 with a full rebuild then. All of the inserts still look to be close to flush with the block and the painted finish on the studs, looks fairly good. Before i pulled the engine for tranny work, i put a torque wrench on all of the head studs and none were loose, (and appear not to have been rusted solid)

The part number is: " 930.101.170.02 OE ", as shown on Schneider ********'s receipt from april 2005.

I am very apprehensive about splitting the case since in 82, the case was linebored, and i fear that these were the dreaded oversize, (now likely unobtanium) bearings.

A little more background, (or maybe foreground), The plan is to continue with the MS/PMO ITB build, 10.5 CR CP pistons, 92mm bored and plated cylinders, Crank fired EDIS twin plug, RSR wheel and KEP all alum clutch for a responsive, fun car doing a few DEs.

Should i risk F*ing up the threaded inserts to replace the head studs. Are these studs likely to be durable enough for the intended purpose or is there a significant risk of failure.

I'd appreciate any/all advice from the cognoscenti, (geez, i can't even spell).
Thanks,
chris

[chrismorse]

Stud pics, easy guys, :-)
chris

[chrismorse]

[Flat6pac]

Those are the 993 dilvars
History writes them as excellent longevity unlike the 911 dilvars that can’t be retorqued
Last time I looked they were about $45 each so too expensive to use in a street car.
Bruce

[chrismorse]

Thanks Bruce,

They look good, and I feel better about leaving them in place.

They cost $25 each in 2005 - a few years ago.

Lord knows, there are enough other parts that need upgrading.

Thanks again,
chris

[proporsche]

yup, as Bruce said leave them alone;-)

Ivan

[Focker]

It all depends on who you ask.

If you ask Porsche Motorsports North America, Singer, Rothsport, Guntherwerks, William Knight among some builders, they will tell you that they use these studs extensively.

If you ask Henry Schmidt, owner of Supertec, he'll tell you these studs are a monstrosity and shouldn't be used even in a generator and that the Supertec studs have superior metallurgy.

As they say, opinions are like @ssholes. There's at least 286,963 posts and threads on here arguing various points. With your own research I think you will find that there is a consistent theme among all those posts and threads.