ptuomov

How about including some contact information so people can send you offers for those or similar cams? I know many people are not interested in doing that publicly.

ROG100

For the record --- GT Cams

928 105 274 01 = No Stock
928 105 273 01 = 21 in Germany
928 105 271 01 = 21 in Germany
928 105 272 01 = 16 in Germany

$1122 each

Carl Fausett

I can help. Our cams profiles and selections are published here:
http://www.928motorsports.com/parts/camshafts.php

When the GT cams started to get scarce (several years ago) we started having them made for us using S4 cams as cores. A lot simpler than trying to find a used set in good condition.

I would recommend you replace them in pairs, however.

ptuomov

Is it really true that you can change the S4 lobe center angles to GT lobe center angles? That's a whole lot of grinding and welding...

Jim Morton

Tuomo:

It's not as much material as you would think. There is still the issue of weld / hard face quality and getting a good interface between the chilled cast iron and the weld is still in the "mix" of quality assurance, making billet blanks a wonderful thing !

For a cost effective repair, a modified S3 exhaust cam is really hard to beat.

$0.02

pritz

Hi guys, thanx a lot for all valuable inputs. I am not convinced that S3 will fit GT as acording to Porsche, GT has all camshafts different to S3 or S4 and shared them only with ClubSport. But probably you are much more better experts than I am (knowing just theory and configurator).
I would like to restore it to original shape so thinking about "replacement" is really at the end. And I have found one in the UK.
Seems this forum is very valuable and responding pretty quickly.
BTW new one costs 1 000 EUR here...
Thanx and take care.
Petr

Carl Fausett

There will always be that issue. No matter who makes them or what they are made from. Even "new" billet cams can have inclusions and bad grinds, just like everybody else. Buy from a reputable manufacturer that fully warrants their product, and who has made them before.

We have not had any camshaft warranty claims nor any fail in the field. And I use them myself on my own car too.

pritz

Carl, your pictures look great!!!
I will try to source the one from the UK as best price/performance due to shipping costs as I am based in the EU. If the one will look bad I will try yours!
Petr

ptuomov

I was under the impression that the 928MS / Webcam camshafts would inherit the LCA of the core. Perhaps I am mistaken, vaguely recall having an email conversation about this though.

Carl Fausett

No, your memory is right. We can alter the offset angles a bit, but not a lot. To compensate, our GT cam is slightly more aggresive than the factory GT cam Intake lift/duration of .393/214, Exhaust lift/duration of .353/200). Seems to work very well. But, these are reasons why we only sell them in pairs and want to see them installed in pairs....

RyanPerrella

How long have you been selling these cams Carl? How many sets have you sold that are actually in running, driving cars?

I'm not saying that what you posted above isnt true, but is it not perhaps a little to early to be making the statement at all?

Carl Fausett

I have been working with Webcam and selling the cams they make for us since 2008. In addition, Webcam has been grinding, rewelding and remanufacturing cams for 20 years before that.

I would be the first to agree that if a manufacturing process is not carefully controlled, the product will be poor. I can say that about anything and anybody's cams, however.

When cam grinding and re-welding has gotten a bad reputation it has been in embrittlement and inclusions. Embrittlement is caused by not carefully controlling the cool-down period after the weld allowing the cam to cool to rapidly, and inclusions can be added if the field is not properly purged with shielding gas during the weld.

I find WebCam to be a quality manufacturer that controls their processes very well, and our product has enjoyed a high success rate. Attached is a photo I just went and took for you of our cams after they have been run in a race engine.

Remember cam grinding and welding has been going on for about 100 years now. Its a well-accepted process, but it has to be done right.

Are they as good as new billet cams? Argueably. If you can GET new billet cams, if the manufacturer is good, and if the lobes can harden before they are ruined (new cams are "soft" and must be hardened via heat-cycling and special break-in procedures. This is especially challenging on race engines where spring rates and lifts are high).

When working with a re-ground camshaft, the cores have already been heat-cycled many times and taken their set. The resulting camshaft is not as soft as a new cam, and less prone to damage during the break-in.

Imo000

The part number between the S4 and the GT is different but they are 100% interchangable. The S4 cams are a direct fit into the GT heads. The only difference is maybe 10 horsepower and even the S4 has more than 300 hp, you will not notice the difference. Go with a nice useds set of S4s and save yourself all agrivation and a bit of money too.

Cosmo Kramer

Isn't there a modification that has to be made to a S3 cam to make it work in a S4 and up engine?

Mike Simard

I can help with new billet cams. I've been making camshaft cores and having another shop grind lobes but now am setup to handle everything in house. It's a lifetime dream coming together and the first sets are being worked on now.
My specialties are uncommon engines and 928s of course!
If you ever want to offer billet cams let me know.

There's alot to say about heat treating and materials and I would babble on if started.
Some trivia: Race cams at high rpms have an easier life than street cams!
Idling is what kills cams, being stuck in a traffic jam on a hot day is more harsh than a race. This is also the reason F1 cars idle at 4000 rpms.