These got buried in another header drama post, And I thought they looked interesting.

These are made by http://www.prospecracing.com/ . Looks like they use a pin to lock the gear at a certain setting to prevent slippage.




St Corsa (www.stcorsa.com) makes them too, in a little bit diferent style. Vtecvoodoo has them and seems to like them.



Any thoughts?

 

thses look a little stronger than the first set. kinda decent idea for those who cannot line up 2 little lines.... i am actually suprised someone came out with those.

 

They look user friendly unlike some other gears that rub out and cant line up exactly!!

 

On the contrary, I'm surprised we haven't seen more of this type of design. The locking pin basically removes any possibility of the pulleys slipping once the desired timing has been set. I don't think this is a "dumbed-down" cam pulley, but rather a design improvement. I'm sure some will say that properly torqued pulleys won't slip, etc. etc., but I would personally rather be certain that they can't slip. A very good idea IMO.

EDIT: The one potential flaw that I can see is a balance problem, considering the proximity of the locking pin to the edge of the pulley. Depending on how much the pin weighs, the problem might not be an issue at all.


[Modified by Padawan, 12:38 PM 1/31/2003]

 

good thinking. nice idea with the locking pin, yet I wonder if these weigh more than "conventional" camgears, plus the question of an unbalanced rotating cam assembly makes me not like the idea...

 

The ST Corsa cam gears look really nice. Good idea with the locking pin.

 

I'd rather drill holes through the bolt heads and safety wire them rather than add another bolt to the cam gear.

 

I'm not sure I'm picturing this correctly, as I fail to see how a cotter pin through the bolt head would prevent motion of the cam gear.

I also fail to see how that locking pin works without limiting the range of adjustability of the gear.

For myself, I'll stick with my boring, non-adjustable, stock cam gears for the time being...


[Modified by MK Ultra, 1:41 PM 1/31/2003]

 

 

Safety wire locks all of the bolt heads together.

They effectively hold each other on.

 

i bet those cam gears aren't balanced.....

 

Ah, I think I see.

This would prevent the bolts from backing out, as opposed to a pin that locks the two pieces together.

 

Yes, sir.

 

I've always been kind of uneasy about the cam gears that rely solely on the friction generated by the torqued-down adjustment bolts to keep them in place. So something like this would make me feel a lot more comfortable.

The unbalancing may or may not be a problem. After all, the cams only turn at half of the crank rate, the locking bolt probably doesn't weigh much, and it isn't very far from the center of rotation. Altering the design so that you always have two sets of holes that line up on opposite sides of the center would solve it if it really is a problem.

A billion years ago, when air-cooled VWs were my thing, there were a couple outfits who made adjustable cam gears where the bolts went through a shim that fitted in an oval recess. The outside of the shim was the same size and shape as the recess, and there was a round hole in the shim that the bolt went through. By varying the location of the round hole, the cam timing could be changed. You would just buy a set of shims with the specific timing you wanted to use.

Here's a picture of what I'm talking about:


It isn't a very good picture, but the little round, multi-colored washer-like things in the bag at the top are the shims I'm talking about.

The benefit of these types of systems is that they give you positive placement, with no chance of slippage. The down-side is that they limit you to finite timing values, which may or may not be optimal.

 

That's an excellent idea, but it still won't totally prevent slippage, especially if the bolts weren't torqued down enough to start with.

 

Sweet!

I always wanted an EMPI timing gear for my '74 Ghia. Was going to put it in with the Engle 110.

 

The Pro Spec pulleys are +/- 5 degrees like Spoon and Toda, while the ST Corsa's are +/- 10 degrees. Only "problem" is that the increments are 1 degree, rather than infinite with conventional pulleys. The upside I see with the ST Corsa's is that an extended range of adjustablity can be offered without the potential for valve/piston contact as long as the clearances are known. In other words, +/- 5 degrees may potentially be limiting, but is intended to prevent damage if a conventional pulley ever slipped while running high lift/duration cams. Since the ST Corsa's can't slip, no such limit is needed, and a greater adjustment range can be offered.

 

I think 1 degree steps are good enough for us. How much power could possibly be hiding between degrees?

 

.....the toda gen 2 camgears can go as much as 20 degrees. I've done it before.

 

I was referring to the original Toda/Spoon pulleys. Why Toda chose a design with such a large range of adjustment is beyond me, but I would be even more concerned about slippage with so much movement possible.

 

Any other companies make this? I'm looking for one for the H22A

 

looks like a good set of sprockets, safe too

 

Link does not work for me, what do these run?

 

I have a set of ST Corsa cam gears lying around waiting to be installed, I like the design of them, looks to be well thought out. The locking pin is a little specially made Allen head bolt. Overall quality of machining and fit and finish is good, and so is the price, i got mine for 169.99$ from http://www.hogens.com
I can take some detailed pics tomorrow if any one is interested.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99ITR#3715 &raquo;</TD></TR><TR><TD CLASS="quote">I have a set of ST Corsa cam gears lying around waiting to be installed, I like the design of them, looks to be well thought out. The locking pin is a little specially made Allen head bolt. Overall quality of machining and fit and finish is good, and so is the price, i got mine for 169.99$ from http://www.hogens.com
I can take some detailed pics tomorrow if any one is interested.</TD></TR></TABLE>
James i also the nicest guy I have ever met... Definitly hit him up for these..
Hogens.com or message Tweakmeister on this board for them. He is the NE supplier for them.