ok, here's my experience with gear drives. This is a very disputed topic on alot of other message boards as well.
Pros of gear drive
Absolutely no chain stretch
more reliable in VERY high HP
It sounds like you have a blown car...
Cons of gear drive
More expensive than a good double roller
up to 7% loss in hp due to frictional loss (dyno proven)
Not really meant for a vehicle that gets driven a fair amount of time
Even the quiet ones get annoying!!!
they can cause a "jitter" in your distributor which throws your spark out of wack
Many times when you use gear drive it wears your cam bearings out faster on the top side (the gears try to spread)
did I mention they get REAL annoying? To the point where if you are driving for a longer amount of time say an hour or more you WILL have a headache!
Alot of people who have had gear drive for any amount of time will tell you to use a double roller or a silent gear drive at a minimum. The noisy sets will just plain drive you insane! Most of the people who stand firm on gear drive as a great product, haven't had it long or use it in a car that is in essence a race only car.
IMHO a double roller timing set is hands down the best option. Why pay $150+ for a gear drive when a double roller can be as low as $32 and that's for a comp cams, not a no name. Without knowing what engine you plan to put this in... This is, IMO, one of the best options
http://www.naparts.com/ProductDetail.cfm?ProductId=2052 And still about $50 cheaper than your lowest price gear drive.
Here's a good reference about the matter which came from the reher-morrison engine building manual
Josh
WOW, sorry about the big picture!!!! Contact a local engine builder and ask him what his experiences are when tearing down a motor that had gear drive. They almost always say the cam bearings were badly worn.
In the defense of the gear drive wearing on the upper part of the bearing, wouldn't the same hold true to the chain but on the bottom?
Bagram AF Afghanistan
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