Does any one make a 7.5 degree advance cam gear in metal either steel, brass, or alum? I have checked all my vendors catalogs and haven't found any. I don't trust the plastic ones.Bob
The "plastic" (nylon) ones are all to often confused with the plastic teeth GM put on their gears years ago to suppress gear noise. It was a poor choice due to running against a chain. I would have no problem running one mated to a new steel crank gear and a new steel generator gear.
I don't think an advanced gear is readily available however it isn't hard to set up your own. If you have an original steel gear you can make a drill guide and using the dowel pin holes from the original, drill you new ones. All you need to do is set it up with a 1/2 tooth offset and clamp them together. My drill guide has a shaft brazed to it so to ensure it is concentric.
Once it is drilled, looking at the front of the gear, make your new timing mark which is now only 1 1/2 teeth from the centerline of the dowel pins as opposed to 2. Engrave both the timing mark and the dowel pin holes so you don't mix them up.
If I am not mistaken doesn't 1 tooth on the cam gear amount to about 7.5 degrees
Jeff,
One full tooth on the cam gear is 15 degrees on the crankshaft. Too much advance. Look at this thread for a photo:
http://www.mtfca.com/discus/messages/257047/318200.html?1351568346
Jim
Well I did make offset dowel pins for a cam gear one time, that must be what I am remembering. I wasn't overly impressed with the results as I recall.
The folks that make the Stipe 280 cam make an adjustable cam gear that I have seen and it looks to be good quality.
I have two nylon advanced cam gears in two cars and have had no problems with either on. Mine come from White's machine shop in PA, and not only do the cars have a lot more power, they are great folks to deal with. I highly recommend these folks and the product too.
The Stipe cam gear is aluminum. Sorry, I forgot that part.
Stipe's adjustable cam gear is aluminum, and it's very pricey. The advanced nylon ones are available from Lang's for a reasonable price, and they work very well. Dean Yoder has 18,000 miles on one, and he says it looks like new.
Isn't the stipe 280 advanced 4 deb? How would that cam work with a cam gear that is advanced 7.5 deg? Wouldn't that be 11.5 deg advance? Would you sacrifice much on top end?
I can supply a cam gear with any advance or retard you want.
dmcgears@yahoo.com
Robbie, Advancing a cam is relative to where the intake valve opens on a particular cam. The Stipe cam opens at 10 deg ATDC. Advancing it 7.5 deg shoulden't hurt. Our cam is already advanced and the intake valve opens at 2 deg ATDC. Advancing it would hurt performance. You have to know what you have and what your doing or you may make things worse than they are.
Gary Tillstrom is right about the GM timing gears. They had nylon teeth on an aluminum hub(silent chain type). As the chain wore, it placed strain between the teeth until they started popping off of the hub. Then they landed in the oil pan and would plug up the oil pump pickup. Don't ask how I know this('72 Chevelle SS454 with spun rod bearing). Not a good idea. The all nylon(or whatever they are made out of)gears should be just fine, although I have not had any experience with them myself. I just use the old original gears, noise or not. I can't hear any gear noise above all of the other racket in my T's anyway. JMHO. Dave
Ford used nylon teeth on the large pot metal cam timing gear on all engines built from the early 1960's through the 1980's. This on every size engine fronm low performance 289-2V to the 428 Cobra Jet. They are notorious for falling apart from age in low mileage cars causing all sorts of carnage.