Deves or Goetz?
 

Hi Folks,

I'm in the midst of a top end here on my 87 3.2, and (thank God) I have Nikasil Mahles which look good. I'll be reringing them and I've had people telling me conflicting things about which rings to use. Seems like everybody has a favorite. A local shop tells me that they always use Deves because they seem to seat better, but I've read here that people like the Goetz as well or better.

Any concensus on which type to use?

Also, I'm changing out all the studs. Short of going with ARP or Raceware, are the 993 steel studs the preferred choice these days? When I look for studs, I find two part #'s:

930 101 170 02S (listed as Dilavar)
993 101 170 51

Thanks for any insight,

ianc

Deves rings are crap. I wouldn't use them in a lawn mower.
4 piece oil ring is 50/50 at best in a new, round cylinder. Put that non sense in a used cylinder and you might as well draw to 7, 2 off suit.

Geotze or ProSeal from JE are the best choices.

As for head studs there is no question that Supertec head studs are the best.
Unique design, life time warranty and a great price for the quality. I keep waiting to hear one complaint about Supertec head studs.
Read this:
http://forums.pelicanparts.com/showthread.php?s=&threadid=235676&perpage=20&pagen umber=1
They are for sale from our host.

Re: Deves or Goetz?
 

The steel head studs are 993.101.172.02. They aren't listed in the Pelican catalog but they do sell them. Use the grey search box in the upper left hand corner of this page with this Porsche part # and you'll find it.
IMO, it's not really necessary to replace the steel upper studs that you have now, just the bottom ones.
-Chris

Hi Henry,

Thanks for the advice; I think I'll go ahead and grab the Goetze rings.

As for the studs, this is just a street car, so your studs, while works of art, are probably a little overkill for me. Heck, the factory studs still look good, but I'm anal...

Chris, thanks for the word also. I'm a little baffled as to the discrepancy in the part #'s. I asked a local shop and they just said use the 993 studs, which they said are threaded along their length.

When I look in IMC's database (and Worldpac's), they list a 993.101.170.51, but you mention 993.101.172.02. Any idea what the difference is? I'll probably be ordering from one of these two. Don't worry though, I ordered the G50 cross shaft update from our host. ;)

I assume the dilavar studs with the 930 part # are right out...

Hadn't thought of only doing the bottoms, but I'll have another look at the tops though...

Thanks guys,

ianc

Searched a little more and found the answer from our resident genius Bill V.

Thanks again guys,

ianc

Just to clarify, there seems to be some confusion.
The fully threaded studs ( what some people call 993 studs) are the evil Dilivar stud. The reason for threading the entire stud eludes me but they are definitely Dilivar.
The easy way to tell Dilivar from steel is with a magnet.

Dilivar studs are not magnetic. Steel stud are magnetic.

These are Evil, run for your life.:)
http://forums.pelicanparts.com/uploa...1152141975.jpg

I'm wondering about the whole dilivar thing now. Did they get dilivar perfected finally so that it was only the early studs that had troubles? Steve Weiner seemed to intimate that in a different thread. The 993 studs seem a popular choice... Just wondering.

ianc

Dilivar was a mistake from the start and was finally abandoned by Porsche and replaced with steel studs in the last air cooled engines.
The thing to remember was that Dilivar stud were never about performance. They were an ill faded attempt to prevent the heads from leaking after the engine was shut off. They (Porsche) got tired of warranty repairs for oil leaks so they sacrificed performance for peace of mind. In the end they realized like most of us that Porsche engines will be moist no matter what you do.
We build performance so we decided that making the heads seal during hard acceleration was far more important than what the engine did while it was resting.
For some of you, your Porsche car is always resting so Dilivar studs, Maguiar's and cup holders will work just fine.

Ian:

We've had really good luck using either steel or the Porsche Motorsport studs (Dilivar) in the majority of our motors with excellent success. The early, troublesome Dilivars get tossed in favor of the above depending on displacement and application.

ARP & Raceware's can be used as long as one keeps a close eye on head nut torque since they can loosen over time.

I've not tried Henry's yet so I cannot comment on how they might compare with the others.

All the steel 993 studs (993.101.172.02) I've purchased were not fully threaded. I think the first steel 993 studs I bought were in 2004 so maybe they changed the design before then?
-Chris

Thanks alot for the information guys, I appreciate it.

ianc

I replaced all with new steel (got rid of the Dilvars) not all threaded for the uppers and lowers..don't have the pn handy but I think EBS had a good price...something like $9/ea. Right now I don't see any leaks...but just doing some track days not racing. The word around here is that very few if any steels have broken.