12 or 24 new head studs?

[tom.langborg]

Hi
Should i replace 12 or all off my head studs?
The car is 3,0 sc -83 only street racing.
Two off them are broken.

/tom

[88-diamondblue]

The intake (top studs) are steel. You should only need to replace the bottoms studs. If you upgrade to Supertech or ARP studs then all 24 need to be replaced. I replaced just the twelve lower studs with steel studs on my rebuild @ about $10/stud.

[tom.langborg]

Thanks
Just what i was thinking.
But i have to ask.

/tom

[Roslin]

Mine broke 6 of the lower studs, 1 in each cylinder..

I bought 12 new all threaded 993 Dilavar studs, so the plan was only to replace the lower one's..

I know many people don't like these studs, but if they work fine in the 993 ? - then you should get the same efekt as when the engine was new.. my car is std. and are only used in summer for road, an Nürburgring one or two times a year - i hope they will last.

Regards Roslin.

[afterburn 549]

Its a bummer when one breaks....... I would ( did ) go with all new

[911pcars]

...which brings me to ask this question related to replacing 12 or 24.

If the upper 12 are steel, why can't they stay and just replace the lower 12 with ARP, Supertec or just factory studs? If the upper studs are worthy of being reused, why must one use all 24 of the expensive versions?

just curious,
Sherwood

[Jeff Alton]

I either replace the bottom with Steel or replace all 24 with the same material. I don't know if it makes a difference or not, but I like them to all be of the same material. Just makes my happy I guess!!

Cheers

[88-diamondblue]

Sherwood,

The Supertech or ARP will have a higher clamping load than what steel has. I would not mix and I'm not sure you can buy them as singles, just sets of 24. I am with Jeff on the all one type. I would have used Supertech if the budget had allowed.

Also Carrera dilivar studs were epoxy coated to prevent corrosion, didn't help and the broken studs in Carrera's are on the rise. My car was stored winters all if it's life. JMHO but all dilivar studs will eventually break. It used to be rare to hear about broken head studs in Carrera's, not any more.

[Jeff Alton]

On the last few 3.0/3.2 motors I have done I went with steel lower studs for a similar expansion rate/clamp force. To my simple mind it seemed like a good idea My 3.4 is my first motor with ARP studs. I would be willing to try Henry's studs on my next motor as well.

Cheers

[ChrisBennet]

The top 12 will never break. I'd just replace the lower 12 with the 993 steel studs, part # 993.101.172.02, Pelican part # OEM-99310117202.
-Chris