993 head studs

[pjh69911]

does anyone know if the 993 head stud has a coeficient of expansion similar to aluminum(like the dilivars?) and if they would work in a 2.7 motor? TIA Paul.

[yelcab1]

993 head studs are supposed to be the cure for that dilavar stuff.

[Bill Verburg]

Originally Posted by pjh69911

does anyone know if the 993 head stud has a coeficient of expansion similar to aluminum(like the dilivars?) and if they would work in a 2.7 motor? TIA Paul.

as yelcab1, yes, the fully threaded 993 suds can be used on all 911/964/993 and is a very reasonably priced quality part. For a little more the 993tt/RS studs are a little better.

[Wayne 962]

Yup, what Bill said. You can use the 993 ones. You can also use the original steel ones - they work very well, and are nearly impossible to break. Porsche was trying to apparently solve a problem that didn't really exist when they used Dilavar on the shanked studs. The 993 ones are not shanked, and are not made of steel, but made of a Dilavar, or Dilavar-like material...

-Wayne

[Schwarzeritter]

As Wayne mentioned above, the 993's are good items.
from my own research I found that the 993TT's were a excellent part, and that some have
had issues with the ARP pieces. I personally have never had a issue on other applications using ARP parts. But I heard that the 993TT pieces good. I cant vouch for the RS, as I am not 100% on the difference between the two pieces alloy or design wise.

Best of luck~

[ChrisBennet]

Originally Posted by Wayne at Pelican Parts

Yup, what Bill said. You can use the 993 ones. You can also use the original steel ones - they work very well, and are nearly impossible to break. Porsche was trying to apparently solve a problem that didn't really exist when they used Dilavar on the shanked studs. The 993 ones are not shanked, and are not made of steel, but made of a Dilavar, or Dilavar-like material...

-Wayne

I think you missed where he said he had a 2.7...
You don't want to be using steel studs on one of those.
-Chris

[911pcars]

Dilavar is a non-magnetic steel alloy with the same approx. coefficient of expansion as aluminum.

Dilavar Ni13 contains 13% Nickel, 5-6% manganese, 3-4% chromium + other alloys. As spec'd by Porsche, ultimate tensile strength is 180 ksi. *

Expansion coefficient,
Dilavar, 11.3
Al alloy, 10.7-13
Mag, 14
Mild steel, 6.33
Grade 4 Ti (6Al-4V), 4.6

AFAIK, the 993 fully-threaded heads studs are also Dilavar, but so far, this version don't have a history of breaking.

Sherwood

* Metals, Fibers and Materials, F. Aird, 1994