Gawd - another dilivar question
 

Do only lower row dilivar studs break, or is it that uppers would break too, it'sjust that Porsche seldom installed them there?

I ask because I'm building a 964. It has no broken studs now. Maybe a good compromise would be to leave the upper dilivars be, and replace the lower row with 993 dilivars

I wasn't aware Dilavar was ever used for the top studs but it wouldn't be the first time I was wrong!

Porsche ran full Dilivar stud on Turbo's and the 993

As best I can tell, my '91 964 has never been apart (unless it was very expertly modified to leak addtional oil :D ). The upper row studs are black painted, smooth, and non-magnetic. I assume this means dilivar.

I have seen broken Dilivar studs on 964's. I would replace all the Dilivar studs.

Were the broken ones upper or lower row? Were the uppers dilivar?

on a 964, they are all dilivar.
Bruce

My 964 engine had all steel, my friend 964rs likewise.

If I have interpreted right, PET implies that 964 may have been all steel for the M64.01/02/03

The turbo (m64.50) had steel upper and Dilivar Lower

PET has superseded all studs for the 964 to the 993 Dilivar.

I seem to remember that in the introduction of the 964 they had Dilivar installed originally, but the failure rate of the stud prompted Porsche to use the Steel studs ....Anybody recall this?

Dilavar is non-magnetic, but also a steel alloy.

FWIW, here's Pete Zimmerman's take on Dilavar:
Cylinder Head Studs - Porsche Wiki

Sherwood

964
 

Introducing Senor Valdez, possibly the most interesting (if not leakiest) 964 in the world. Upper and lower studs non-magneticNo evidence this engine has ever been apart until now. ~90k miles. Note ims bearing wear, which I find to be typical. Rod and mains are in great shape. This is to those who decide to just do a top end, not knowing what lurks inside.

http://forums.pelicanparts.com/uploa...1416086874.jpg


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