adjustable cam sprockets for 91-95 belt

[Kohburn]

OK i've finally gotten around to designing the adjustable cam sprockets and pricing them - the current design uses the stock sprocket - removes the center section and adds in a two part machined aluminum core that ajusts the same as al the other aftermarket cogs for other cars..

i am going to price out one more design that doesn't require using the stock cogs as it may possibly reduce the cost of the cores required ..

current design pricing is looking like 250$ +$100 core charge for the stock sprockets..(30$ a pop from gm parts direct)

if there are 10 people willing to lay down money and can let me know how many will have a set of 91-93 stock sprockets to send me then i can move forward with production.

Everyone have a Merry Christmas - i'll post an update next week

[Juglenaut]

Somehow I doubt just any aluminum will work. Remember aluminum lightly bonds to steel under pressure, 2 different metals with different metallurgy properties especially a hard steel alloy against even most grades of aluminum. Steel on aluminum equals will not last.

There is a rather good amount of tension on the cogs and aluminum is not very strong with applied torsional force, coupled with applied tension.

[HayesPerformance]

Hey kohburn,

If you want a good example of a Adjustable Cam Gears take a look at a set of AEM Tru-Time Adjustable Cam Gears. There great in seeing what you have involed in making them.

Regards,
David Hayes
President of
HAYES PERFORMANCE PLUS

[dohcfiend]

can you possibly copy a stock set? if so can you get me a quote for a 96-97 set made out of 7075 aluminum? you also have a pm.

[dohcfiend]

also another tip, stick to 94-95. 91-93 are a PITA to remove.

[Juglenaut]

7075 aluminum should hold up if the whole cog is fab'ed out of it and slightly larger at the stress areas. I still doupt it will hold up if is a two piece this is not a chain driven cog where just enough tension is applied to keep the teeth in the groove.

Belts are tensioned in a way to not only keep the teeth in the groove but also allow it to stay alined on the cog.

If the whole inner part of the cog consists of the adjustment system and somehow the outer is fab'ed to the cog and the assembly that makes up the adjustment part fab'ed to fit directly to the cam. Kind of like a lockable clutch system with 3 degrees every stop. this clutch would have to prevent the cog from reversing like a one way bearing.

[HayesPerformance]

Here is a picture to help

Hi to all,

Here is a picture to help.
Regards,
David

[HayesPerformance]

That Pic should help for designing it.
Automotive Performance is what I do for a living. If you need some of the parts made let me know.

Regards,
David

[Kohburn]

yes that pic pretty much summed it up - the design is simple - no need to overcomplicate it because that just makes it even more expensive to fabricate.

also another tip, stick to 94-95. 91-93 are a PITA to remove.

they have to remove them to install these - and if they have an extra set they can get a core charge for them before i start fabricating the cogs.

All i need to know right now is if enough people are willing to pay the money - or if its a waste of time

(oh if only 5 people are interested the price would be +$60 per set)

[HayesPerformance]

Set meaning 2 or 4?
I would buy a set if I like the look of the finished product. Do you have a set done?

Let me know.

If you wanta E-mail me its: hayesuniversal@shaw.ca
Regards,
David

[HayesPerformance]

By the way, are all the cam gears for all the years the same size? I never looked.

[Kohburn]

cam cogs are the same size for 91-95 , 96-97 uses a different belt - these could be used on a 96-97 by replacing the belt , drive gear, idler pulleys, and tensioner pulley with one form a 95

i have some good news - the price has come down and no core will be necessary - i got a price on having the two peices of each adjustable cog FORGED!! from 2024 aluminum (better than 6061 and 7075 for this application anyways) - they will of course be hard anodized black and be assembled with stainless steel hardware, unlike the cam tool the degree marks will be engraved.

a set would be all 4 replacement cogs - currently looking like i can provide them for only 215$ per set

[Juglenaut]

2024 is an alloy, but will work nicely.

I don't have a DOHC as of yet so I don't need any. However I do have cogs.


However take a look here about this alloy:

http://www.suppliersonline.com/propertypages/2024.asp

http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA2024T4

A hardened steel alloy (carbon steels) will have higher working temps. It might be better off for longevity if you used hardened steel alloy, since the cogs that will be replaced is a hardened steel. Also steel has alot more cycles.

[Kohburn]

2024 is an alloy, but will work nicely.

A hardened steel alloy will have higher working temps. It might be better off for longevity if you used hardened steel alloy, since the cogs that will be replaced is a hardened steel. Also steel has alot more cycles.

an alloy? you don't say...

I'm more than familiar with material properties, thanks - hardness is a non-issue with a rubber belt - but incase you were wondering 2024 is harder than many steel alloys - as for longevity? its a pulley with teeth, not suspension part that is going to take repeated shock loading - the forces on a cog are very uniform.

I'm not going to make them out of steel because it is unnecessary, would add extra weight, and increase the cost - which so far nobody wants to pay anyways.

[dohcfiend]

2024 is an alloy, but will work nicely.

A hardened steel alloy will have higher working temps. It might be better off for longevity if you used hardened steel alloy, since the cogs that will be replaced is a hardened steel. Also steel has alot more cycles.

an alloy? you don't say...

I'm more than familiar with material properties, thanks - hardness is a non-issue with a rubber belt - but incase you were wondering 2024 is harder than many steel alloys - as for longevity? its a pulley with teeth, not suspension part that is going to take repeated shock loading - the forces on a cog are very uniform.

I'm not going to make them out of steel because it is unnecessary, would add extra weight, and increase the cost - which so far nobody wants to pay anyways.

your idea is great, but your timing sux. but IMO nobody is going to be rolling in dough right after xmas. wait until tax time then you may get more of a response.

i know i am spent right now .