Gregg K

Well, I've just pulled off my cam cover for my first peek, and my cam gear is the worst I've seen. I'll be watching this thread for any updates on where we are going with new gears.

Gregg K

A couple of comments. I share the sentiment with someone up the thread regarding different and significant sprocket weight. At half of engine speed, it may not be an issue, but resonant vibrations can be very problematic. I'd be a little worried if the part were significantly heavier. Having said that, the forces that the cams place on the rotation of the camshaft is probably far more than anything the added weight of a heavier sprocket could induce.

Also, a combination part whereby an inner alloy sprocket is effectively glued or fit to an outer good wearing part could be a bad situation if for any reason separation were to occur. And with combined cycles and heat and force, I wouldn't want a part that has that configuration.

Also, I'm in immediate need of these parts, as are others. I can mothball the car for several months, but two less gears will be in demand if it takes much longer than that.

ROG100

As far as 928sRus is concerened we are making a one piece gear machined from solid.
Gear will weight about the same as the original or the latest iteration - 13 to 16 oz.
Gear will be anodized or hardened in a way to stop wear as per the latest Porsche gear.
Programs have been written and prototypes are being made.

fraggle

All this sure isn't going to make 928s more common at porsche events, that's for sure.

I'm up for two replacements when the details are worked out. I'll stock 'em for my next belt job. I swapped my very used ones for less used ones last time around. I'm sure they'll be cooked by next time.

ROG100

I have a number of the earlier HTD cam gears 928 105 545 10 for $110 each.
These fit the 83 to 86 16v cars.

Gregg K

OK, I've just submitted this to the best place I know.

http://www.practicalmachinist.com/vb...1/#post1478997


Edit- Whoops! I underestimated the degree of seriousness in pursuing the problem. Thanks Russ. I'll just see what the machinists say, but if your sprocket/gear is done in the relatively near future, I'll be taking several.

Gregg K

First manufacturing solution has come in. Extrusion. I don't know why I didn't think of this.

Extrude out of 6061-T6, then hard anodize. But that last step does alter dimensions somewhat. The extrusion die is 2-3K in cost.

I'll post more as they come in. And the thread url for anyone interested.

Dave928S

Put me down for two ... and I'm sure I can think of a few other things to fill a flat rate box.

Thought I should do my bit for the Tyson Xmas fund ...

Gregg K

HELLO!!!!

I got an interesting reply here- There are premanufactured extruded blanks that can be simply hogged down to proper dimensions.

Here's one supplier- http://www.gatesmectrol.com/mectrol/...cation_id=6019


There's more at this link- http://www.practicalmachinist.com/vb...1/#post1479069

Gregg K

More comments.

This guy does timing belt sprocket work. And he's highly knowledgeable in the field, evidently.

http://www.vermontel.net/~gwi/

Another forum member says he should be able to pull off these sprockets for under $100. That's probably before anodizing.

danglerb

I know many will want close to factory, but I hope some option exists for the raw gear so other coatings can be explored like DLC or WPC.

ROG100

Gregg K,
I have already been down those same roads and I am sure Greg Brown has as well.
We have already chosen the most cost effective way to produce the gear and also the material and finish. Lots of companies out there who can make gears - not an issue.
Roger

Landseer

Thanks Roger.

M. Requin

Roger, you might consider this proprietary, but when you have these ready for sale I hope you can give us the specs on alloy and surface treatment. Your progress on this project has been impressive!

blown 87

One thing I hope every body keeps in mind that who ever makes these gears, Roger, Greg Brown, or who ever is going to have them made is going to have them made is going to have to make money on them.

This is not a hobby to them.

Four hundred on a gear that cost 100 to make is excessive, but IMHO 130 is not enough profit for any body to do this.