Special Supertec case through bolts?
 

I thought I remember Henry saying that Supertec offers a special case through bolt for use with hightly stressed mag case applications. I searched but couldn't find any threads to that effect. All I found is Henry's statement that he prefers the fine thread case through bolts from 78 and later 3.0, 3.2 and 3.3 engines.

Henry? Anyone?

I think you are confusing those with the head studs he sells.

No, see thread ID 193503 where he says he may produce the racing case through bolts. I know he sells the head studs, which I plan on purchasing.

He usually answers the phone...

I don't know if Henry has or is producing them, but according to ARP's 2006 catalog that I have (page 74-75), they offer an upgraded case through bolt kit for all the 2.0L - 3.3L 911/930 variants as well as the 964/993 3.6L-3.8L motors, but have never seen or used them...:)

Part number 204-5405 for your application....:)

Ralph

I have been considering making case through bolts. We haven't as of yet. I want them, it's just very expensive to do this kind of product development.
The late (78-88) through bolts are far superior to earlier versions mainly because they offer more consistent torque values from fine thread nuts.
The shank on the late studs is also thicker than the earlier versions.
Hummm: sounds a little like my head studs.
Do you need the upgraded studs? Only if you want your engine to have the best possibility for success.

Henry (and anyone else for that matter),
In what applications are you seeing failures of the Porsche thru-bolts, and what types of failures occur? This is one main engine component I haven't seen a lot of negative press on.

Dave, its not the case through bolts that fail. Better case through bolts help maintain the clamp load on the mains to prevent fretting of the case halves and leaks. It's all about the case.

Ah finally you've answered one of my two questions. Now, what about my other question? :D

Gotcha. What kind of build are you thinking on a mag case? Are you considering dowel pins also, especially if you can't find a beefier bolt?

This seems a little cryptic. "Do Do Do Do, Do Do Do Do":confused:
What question ?

Funny, a friend called ARP today and asked about them and was told "we don't make those yet, but we've listed them in our catalog for years." Nice work, ARP.

I do know there is at least 1 set in existence as it was offered to me for free by ARP for testing purposes when I built my 3.5L motor in late 2004.

I had no problem using their excellent head studs and rod bolts, but I didn't want to be a guinea pig for these since I don't plan on tearing the motor apart for 100K+ miles and the fact that the motor is simply a mellow, daily driver version I don't think that I would have been a good candidate for "testing/development" anyway...:)

This was almost 2 years ago when I started work on this motor, I would have thought that this would have been sorted out by now, especially with it being listed in their catalog and on their website...:rolleyes:

Ralph

What is the expansion rate of your studs?
Got it.
I guess I missed that question.
I am not an engineer so when I wanted a better head stud I went to a materials engineer and told him the perimeters we were working with. The cylinder and head materials, cylinder pressures and heat ranges. I left the expansion rate, stud diameter and thread pitch up to the guys who do this for a living. The results were the studs that I am so proud of. We tested 7 different stud designed before settling on the final product.
If you understand materials chart (I don't) you can read about the material characteristics at one of the links I have posted before.
Good luck.

ARP like most large companies is more interested in bottom line than innovative new products.
In the business world getting an "ever growing percentage of an ever shrinking market" is the best way to go broke. Large companies won't risk it for the love of a brand.
ARP will not produce the product until they think there is a reasonable bottom line.
At Supertec we're not that smart. We love the early Porsches and if it's in the cards for us to loose money making cool products, then so be it.

That is a great quote! Exactly how most of us feel about our "gold plated" cars. You should put it on your business card.

FYI, ARP followed through and the case bolts are now available for around $700.