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View Full Version : Adjustable cam gear issue.



86Shelby
01-11-2007, 07:26 PM
I have a pair of custom adjustable cam gears on my R/T. But I noticed while I've had it apart that the center portions of the cam gear were machined incorrectly and the keyway slot is off by approximately one tooth. When I compare the adjustable gears to a pair of stock gears the slot is not in the correct spot. I don't have a problem with the exhaust being off like that other than the fact I can't use an alignment tool when installing a timing belt.

The real question is what effect will the intake cam gear being out of time have on the spark and fuel timing. When the intake cam is centerlined correctly, the outside of the gear is effectively off one tooth. IIRC it's retarded one tooth.

I suppose if nothing else I'll dyno it with the adjustables on it and then swap over to stock gears and see just how much/what kind of a difference that will make.

Directconnection
01-11-2007, 07:31 PM
One tooth on a sohc gear is 9 degrees. Should be the same for a T-III. The gears I made had 12 degrees of adjustability, and the copies that followed were the same. That should be just enough to get you where you need to be even though you get only 3 degrees to play with.

Will Martin
01-11-2007, 08:05 PM
Steve....you avatar.....I'm dying laughing! lol

Directconnection
01-11-2007, 09:18 PM
I stole it from the famous srt-4 thread of 2 weeks ago (ie naked chick pics thread)

iTurbo
01-12-2007, 12:53 AM
Ray, I didn't have this problem with the adjustable cam gears I installed in my Spirit R/T recently. They are probably the same ones you have. Are you going to centerline them with a dial indicator and degree wheel? I did and found that I barely had to adjust them to achieve stock centerlines. IIRC, both sprockets ended up being advanced one has mark on the sprockets timing window.

I would also be a little wary of how this would affect your cam sensor timing reference. Even if you do dial the intake cam in, the outside of the gear will be off which is what the cam sensor reads. I don't think your spark timing will be affected but your fuel injector sync may be off. If you are sure they are made incorrectly, I'd send them back and get another set if you can.

iTurbo
01-12-2007, 01:03 AM
I just checked a second set of adjustable TIII cam sprockets I have with a spare set of stock cam gears. I tightened the centers down to the '0' mark and compared the keyways and they appear to be exactly on. Sounds like you got a bad apple.

86Shelby
01-12-2007, 02:18 PM
Yeah, I know they are off, I was finally able to confirm what the previous owner told me. There isn't enough adjustment to get the center line correctly. I'll just get ahold of the maker and see if I can exchange them or if I can get the center reproduced to have the proper alignment.

MOPAR2YA
01-18-2007, 12:07 AM
All you need to do is back it up a tooth. I had the same problem and informed the vendor (as I was the ginneau pig), and the gear has since been corrected.