Which head studs for a 964 rebuild?

[safe]

Originally Posted by Henry Schmidt

The 964 was never fitting with " plain steel" studs from the factory. In the late seventies Porsche committed to the Dilivar stud to deal with warranty issues [seeping on cool down]. They struggled with design after design and finally settled on the all-thread monstrosity. It was never designed for as a performance enhancement.

Mine was and my buddy's RS. Maybe a row vs us thing.

[winders]

Originally Posted by Henry Schmidt

In the late seventies Porsche committed to the Dilivar stud to deal with warranty issues [seeping on cool down]. They struggled with design after design and finally settled on the all-thread monstrosity. It was never designed for as a performance enhancement.

Yet the 993 Turbo "all-thread monstrosity" head studs are the predominant choice for use in high output high performance large displacement Porsche air-cooled engines.

Heck, even Singer uses them in their builds.

[Turbo_pro]

Originally Posted by winders

Yet the 993 Turbo "all-thread monstrosity" head studs are the predominant choice for use in high output high performance large displacement Porsche air-cooled engines.

Heck, even Singer uses them in their builds.

Cool more hero worship.....

I'm pretty sure every race car used biased ply tires until radials hit the scene.
Some still do......

[dannobee]

At the stealership level, we rarely if ever used aftermarket head studs and we cringed when replacing the broken studs because we'd all seen brand new, just out of the package Dilavar studs break right after torquing them up. Either a few minutes later, or the morning after. It left us with zero confidence in the product while having to wear a happy smile with the customer. The problem is "intergranular corrosion" if you care to look it up. It's a manufacturing/heat treating problem. And like Henry, we saw enough of the earlier ones go bad that we no longer cared what promises the latest iteration had, we just didn't trust them. From what I understand, the 993 turbo ones have fixed all of the problems. They might be the greatest thing since sliced bread. But once bitten, twice shy. Especially now that some aftermarket studs have seen zero failures.


Sort of off topic, but most of the "radials" that I've used in nascar weren't true radials, but more of a hybrid, being a belted tire with a smaller bias angle than the bias ply tires. If you ever see one dismounted, take a look inside and you'll see the bias angle.

It's tough to make a true radial tire that can withstand 200 mph continuous. Not to say that it hasn't or can't happen, but look at all of the tire problems in the current Cup cars.

[Neil Harvey]

Originally Posted by winders

Yet the 993 Turbo "all-thread monstrosity" head studs are the predominant choice for use in high output high performance large displacement Porsche air-cooled engines.

Heck, even Singer uses them in their builds.

That's a pretty bold statement. I don't use them but then again, I'm must not in the high performance business, I guess???? Even I don't know what others use. Just what we do and why.

There are advantages to head studs that have nothing to do with clamping the parts together. Anything that can be incorporated into a part to make its use better and easier to use. Why not??

To clear up a few issues, Singer do not build their own engines. Pinks did some. Pinks were never really in the Porsche business, so using anything aftermarket would be chosen on risk, I assume. Now Porsche builds the Singer engines here in the US and Porsche will always use their own parts.

An absolute sales pitch, what about our studs? We even supply Titanium Exhaust studs that will never fail due to the heat stress that the steel studs suffer from. We also offer the through bolts with the center dowel locking the case half's together.

[Jeff Alton]

^^^^^ Nice looking parts Neil. I assume the through bolt O-ring slides over the locating dowel section easily?

Cheers

[PeteKz]

Neil, thanks for making the titanium exhaust studs. I’ll differ in attributing exhaust stud failures to heat stress. It’s been my observation of not only several handfuls of Porsche studs, but also hundreds of studs in other engines that the exhaust studs fail primarily due to corrosion. However, your titanium studs would certainly help in that regard. Stainless steel studs also would be much more resistant.

[Henry Schmidt]

Originally Posted by PeteKz

Neil, thanks for making the titanium exhaust studs. I’ll differ in attributing exhaust stud failures to heat stress. It’s been my observation of not only several handfuls of Porsche studs, but also hundreds of studs in other engines that the exhaust studs fail primarily due to corrosion. However, your titanium studs would certainly help in that regard. Stainless steel studs also would be much more resistant.

We haven't really seen a heat issue with exhaust studs either with the caveat that turbos get crazy hot.
The only exhaust studs we found required something special were the turbo charger mounting studs. For that we made a 10 X 50mm hard anodized titanium stud. We found better longevity with the anodize process.
We enhance the body diameter to create a more precise hole fitment to reduce movement from excessive vibration.

[winders]

Originally Posted by winders

Yet the 993 Turbo "all-thread monstrosity" head studs are the predominant choice for use in high output high performance large displacement Porsche air-cooled engines.

Heck, even Singer uses them in their builds.

Originally Posted by Neil Harvey

That's a pretty bold statement. I don't use them but then again, I'm must not in the high performance business, I guess???? Even I don't know what others use. Just what we do and why.

There are advantages to head studs that have nothing to do with clamping the parts together. Anything that can be incorporated into a part to make its use better and easier to use. Why not??

To clear up a few issues, Singer do not build their own engines. Pinks did some. Pinks were never really in the Porsche business, so using anything aftermarket would be chosen on risk, I assume. Now Porsche builds the Singer engines here in the US and Porsche will always use their own parts.

Neil,

I guess you don't know what the word "predominate" means in the context I used it. It doesn't mean "all". It means "being most frequent or common".

I don't know what head studs you use. I've never heard your name mentioned when it comes to choices for building high output large displacement air-cooled race engines. I know who built the engines in all the fast air-cooled cars I have come across in my 12 years of racing and you have not architected/built any of them. So I don't know what level of performance you build to. Your engines might be the best or just okay. I have never come across one. I have come across competitive engines from Peter Dawe, Jeff Gamroth, Jae Lee, Kevin Roush, Sol Synderman, William Knight, and Mat Lowrance.

Singer would not choose an engine builder that used inferior parts in their engines. Period!

Scott

[Neil Harvey]

Originally Posted by winders

Neil,

I guess you don't know what the word "predominate" means in the context I used it. It doesn't mean "all". It means "being most frequent or common".

I don't know what head studs you use. I've never heard your name mentioned when it comes to choices for building high output large displacement air-cooled race engines. I know who built the engines in all the fast air-cooled cars I have come across in my 12 years of racing and you have not architected/built any of them. So I don't know what level of performance you build to. Your engines might be the best or just okay. I have never come across one. I have come across competitive engines from Peter Dawe, Jeff Gamroth, Jae Lee, Kevin Roush, Sol Synderman, William Knight, and Mat Lowrance.

Singer would not choose an engine builder that used inferior parts in their engines. Period!

Scott

Yes you are correct. I'm not well known in the Porsche world as I stay in the background supporting many of the shops you listed.

My background is not building Porsche engines like many of the shops you listed. My background was spending many years building engines for F1, Cosworth and BMW, then coming over here and building some Indy engines before working for Toyota building the IMSA 4 Cyl Turbo engine, V6 Offroad and the Toyota Atlantic engine. Then spending a few years working for Andial in the race engine dept., doing all the dyno testing on the 962C engines and some other Porsche race engines. After leaving Andial, I started PD continuing building 962C race engines, some air cooled turbo engines and when the water engines came in around 2000 developing many parts for those. A few years ago when we were asked to build high end high performance air cooled engines we set about designing and developing parts for the air cooled engines, many shown in my air cooled developments post on this site.

So, yes we are not well known in the air cooled "club" scene as we have been too busy designing and building slightly more developed engines.

I wonder, does that make me capable of building a less developed Porsche air cooled club engine? Don't know myself. That I will leave up to customers to come to me and ask.

BTW, I'm buried with work building engines with parts we developed and shown in my air cooled developed parts on this site.

I'm tired, I need to lie down and take nap.

[Neil Harvey]

Is this enough qualification to join the "club" race engine builders fraternity?




Same engine, different day.

But you are right, not many of these in the Porsche club scene. I can only wish I had the chance to built an air cooled large displacement engine instead of having been tasked to rebuild this engine.

Who wouldn't.

BTW, never have I seen any of the shops you list build any of these either. So that makes us all even.

[Axel84]

lol mic drop from neil

[KNIGHTRACE]

This forum is here to HELP people make good choices on there builds or find support.. I ran across this thread and hesitantly posted. I am willing to help anyone that reaches out to me and advise them for their application. I use 993tt on high Preformance builds and I am currently about to try some supertech studs.On the exhaust studs I use steel ones with "copper locking nuts" Never have problems removing them even 15 to 20 years later. Turbo-pro You mentioned my name above asking me to explain my "thought" process on delivar. I think more than most do.

[porschedude996]

Originally Posted by Henry Schmidt

We haven't really seen a heat issue with exhaust studs either with the caveat that turbos get crazy hot.
The only exhaust studs we found required something special were the turbo charger mounting studs. For that we made a 10 X 50mm hard anodized titanium stud. We found better longevity with the anodize process.
We enhance the body diameter to create a more precise hole fitment to reduce movement from excessive vibration.

Henry, please explain how you are getting the studs out without snapping them off. I tried mapp Gas, and i’m afraid to put too much heat into the with a Oxy/acetylene torch . Head’s are fully assembled.

[Helix8]

Neil,
Those who know you know. Thank you for your contributions to Motorsport.

[Henry Schmidt]

Originally Posted by porschedude996

Henry, please explain how you are getting the studs out without snapping them off. I tried mapp Gas, and i’m afraid to put too much heat into the with a Oxy/acetylene torch . Head’s are fully assembled.

If I understand you correctly, you are asking how to remove exhaust studs without breaking them. The answer is heat and patience but even with that, you may have some broken studs. That is why we always remove exhaust and intake studs prior to the rebuild process. During our process, we remove the studs that come out easily, then with the broken or stubborn ones we machine them out and clean the threads when appropriate and insert the threads that don't survive. This process is done in a simple knee mill so while the head is in the fixture we have the opportunity to resurface the exhaust flange.



The studs in the picture are for the turbo housing. Those studs rarely come out so we go straight to the machine process. As Neil has stated, plain steel is not your friend when it comes to hardware in extreme heat applications.

[Neil Harvey]

Originally Posted by Helix8

Neil,
Those who know you know. Thank you for your contributions to Motorsport.

Thank you. That's very kind.

I apologize if I came across as a dick. Sometimes, you need to make a point without actually replying to the question. Pictures often mean a lot more.

Anyway, its Friday and I have lots of work to do, "building high performance, large displacement air cooled engines".

They don't build themselves.

[Henry Schmidt]

Some of the custom hardware we've made over the years to make even our non-racing projects better.
If only I had a real engine architect to help us plan our projects.

[mepstein]

I love the fact that there are really great engine builders that contribute to this site but to assume someone doesn’t know their craft because they aren’t a big online contributor would be a mistake. Some of the top guys are just busy building engines. I’m lucky enough that we speak to Peter Dawe almost every other day but I doubt he has a pelican log in. And believe it or not, he has differing opinions on head studs to his peers. There’s multiple ways to skin the cat and learning why a particular part gets used is often as important as the actual endpoint.

[Turbo_pro]

Originally Posted by mepstein

I love the fact that there are really great engine builders that contribute to this site but to assume someone doesn’t know their craft because they aren’t a big online contributor would be a mistake. Some of the top guys are just busy building engines. I’m lucky enough that we speak to Peter Dawe almost every other day but I doubt he has a pelican log in. And believe it or not, he has differing opinions on head studs to his peers. There’s multiple ways to skin the cat and learning why a particular part gets used is often as important as the actual endpoint.

You are absolutely correct about assumptions based on website contributions.
That said, these are all just opinions and the expertise offered to assist DYI builders is priceless.
Questioning expertise based on some nebulous "racing" credentials is nothing more than an authority fallacy.
Assuming that an application suited for racing as selected by an expert must be the best for all applications because the expert is the best is simply not credible.