Name that stud...

[CBRacerX]

I have these studs in the garage from a former race engine that supposedly had a "962 case". I don't know about _that_ but the case was well prepped for the 3.2 race engine that was built. Too bad the builder did not properly torque the rod big ends, but that is a whole 'nuther story.

So what are these? Vintage 1993 or so, and they are not magnetic. ARP or Raceware (likely) or ???? studs? Would like to use them in my 3.8 build.







And just for fun, here are the case studs and some internal studs removed from the engine:

[Jeff Alton]

Hmmmmm, the ARP studs that I just got today are not magnetic, nut they have a rounded "nose" on the head end of the stud...

Cheers

[Henry Schmidt]

Factory race stud.
I found a set in a 935.

It's almost as nice as my studs.

[CBRacerX]

Thanks Henry, any special requirements when installing these?

Chris

[MBruns]

The studs are Titanium,the cyl studs usually are not but are bright in finish and about 5 mm longer than normal 911 cyl. studs
if they are 935/962 because of the longer cylinders.
Mike Bruns JBRacing.com

[Henry Schmidt]

These studs are the studs we used to design the Supertec heads studs.
We copied the diameter and material then changed the head nut end to a more efficient design. (fine threads)
now the secret is out.
Of coarse there are very few true secrets when it comes to building a quality 911 engine.
The magic is in the quality control.

[blue72s]

Originally posted by Henry Schmidt
These studs are the studs we used to design the Supertec heads studs.
We copied the diameter and material then changed the head nut end to a more efficient design. (fine threads)

1. Hard to see in the photo but is the shank diameter reduced to slightly less than the minor diameter of the threads?


2. What is the material?

[Henry Schmidt]

Here goes.
Remembering that I am a mechanic not an engineer the specifics are as follows:
17-4ph HCR 38-42 4hrs @ Temp 1025
http://www.latitudemanufacturing.com/174PHPrint.html

[CBRacerX]

Thanks again Henry for the detail. Does the installation and torque up process on these differ from the steel versions? For example, should these have anti-sieze in the case vs. locktite?

Thanks,

Chris

[Henry Schmidt]

Blue locTite on the case end anti sieze on the nut and washer end.

[Jim Sims]

Are you using the sintered/heat treated stock (98.5% dense) or the wrought stock to make the studs?

[Henry Schmidt]

Like I said before "I am a mechanic not an engineer"
I knew it would be a mistake to post the material cart.
Someone always takes the discussion in the direction of unimportant minutia.
I have no idea which material was used. I have a complete material certification but I have no idea how to read it.
Here it is , read it and post your findings.

[shbop]

This started out kinda interesting. OK, now I got a headache!

[CBRacerX]

I'm still interested, since the details of materials and process for these "simple parts" are things that some of us take for granted. The facts are that there is a LOT of brain power applied to every aspect of engine design, and those folks who have a "better idea", like Henry's custom studs, need to be very careful that the fix/upgrade doesn't cause more harm than benefit. I applaud companies like Supertec who take the time to "do it right"! It would be great if ALL vendors of engine components and services had such a quality commitment.

Chris

[Jim Sims]

The ASTM A484-D5 on the certification papers indicates it is wrought (think "forged") material. The "cert papers" indicate very good material. Sorry if my question came across as minutiae; the earlier link also showed a compacted powder version of the 17-4ph alloy and I was curious if someone had figured out a method of making powder metallurgical high strength fastener material.

By the way it appears that at least for a while the Porsche 911 engine timing chain sprockets (chain wheels) were made via a compressed metal powder method.

Cheers, Jim