Maybe I should have given my rear world experience with them. a coworker had a "noisy" pete jackson timing gear on his MonteCarlo SS and thought it was cool but got tired of it after a few months. So all he did was switch it with a double roller timing chain from Summit Racing and his idle went up by about 200rpm. We had to bring his idle back down. Now he claims that the raised idle is from the reduction in friction from a roller timing chain and believes it was eating up about 30hp. It actually eats up only 1-2 hp. Like Mindgame said, it negligable.

The advantages of running one far out-weigh the 1 hp loss, more acurate valve timing plus they are more reliable. But with a 224/230 cam, why bother?

 

Mindgame: I didn't mean to imply that gear drives have no place anywhere. But we aren't talking Pro Stock here. We're talking about (from the context) a relatively mild LT1. In that context, I can't see it doing any good. Given the issues with the knock sensor, etc. I would stand by the idea that it wouldn't increase performance and may decrease it, provided the context is a mild LT1. Didn't really plan to debate it, and if someone credible like you said it gains acouple of hp (in this type of application) I wouldn't argue. But it still seems sort of like "aural rice" on a car that's not an all out race car.

Rich Krause

 

Delete the knock sensor in order to get a cool noise and reliable valve timing on a mild cam. Not worth it in my mind. What happens when there is real knock and theres nothin to hear it because there is a cool noise coming from the timing cover. Not tryin to be a ****, just my opinion, if you were running a solid roller 260/280 degree cam with over .650 lift I would look into a gear drive, but not until somewhere close to that point.

 

I run a gear drive in my 76 camaro---It is good for sustained high rpms only which you will not be doing in a relatively mild LT1; besides; even with an LT4 knock module you will notice an idle problem (due to the noise picked up as knock) and the sound will drive you crazy after a while believe me!! You are better off with a jesel belt drive or just a true roller, If you read all the fine print of the gear drives they put in bold letters not for use on an LT1 or computer controlled cars with knock sensors. Trust us when we say not to use it unless you are running serious power or no PCM.
I am ditching the gear drive for the jesel drive in my camaro since the noise from the drive-the noise from my valvetrain and the headers is making me deaf----what was that you said?

 

No arguements Rich.
I was just curious (knowing you have a friend with a shop) I thought maybe you had seen some dyno results. Always curious to see what other people are doing/seeing.
Much of what I've seen has of course been "race engine" tests. WJ and quite a few guys have said that they've seen losses of less than .5% with dual-idler jobs... a little less with single-idlers.... and here we're talking competition level stuff. In the context of this discussion, that'd mean a loss so small that you'd likely never know you lost anything.
I agree though, as I mentioned in my first response, I think it'd be more PITA than it'd be worth especially when you consider that a chain is durable enough for most everything.
The rest of it just comes down to accessability and tuning.... that's where the belts shine but that's another matter too.

-Mindgame

 

Jesel sells one, dont know for LT1s but it costs about 7 or 800. To put things a little in to perspective, that new Comp gear and chain set for non vented optis is about $600. So, if you got money to burn go for it. If not just send it my way

 

I ran a Pete Jackson "Noisy" gear drive in my 79 Malibu 468, 74 Z28 355, 67 Mustang Fastback 351 W, and 85 Olds 442 455 and never had any problems, nor did it ever become annoying to me. I doubt it can rob 30 HP, but I do agree steal 1-2 HP.
As for the "ricer" thing. Having a car once it goes in that runs 12.5xx and lower with stock heads is a "ricer" idea with a gear drive them I guess thats your call.

 

I think a belt is a great idea for getting the last couple of hp out an engine that is already optimized. But now we are really splitting hairs, when you talk about gaining a couple of hp. Winners in high level competition are made from getting a couple of hp here, a couple there. Optimizng things like cam drive, windage, crankcase pressure, etc. Some of these principles can be efficiently applied to a street motor, for sure.

But I am not convinced that a gear drive actually adds any hp. And to my ears, they are noisy and unpleasant. So you combine noisy and expensive with minimal power gain and it doesn't sound like a winner to me. Maybe in a very specialized application, but not on a street car.

Rich Krause

 

Rich buddy, we get the point.

Shaver-Wesmar..... real big with the dirt crowd for rock solid valvetrain. Even show gains but not cheap.

-Mindgame

 

How did I do that?

Rich Krause

 

I'm cheap, Cloyes double roller for me, works great. Belt drive is $599+ yeah, not for me.

 

Would a gear drive fit on a 93 without switching to the vented opti? If so it would be a lot cheaper then getting a double roller and doing the opti swap!

 

Dave Wendland (Dave W 396ci) used a Pete Jackson on his LT1 396 for a while, but he wasn't happy with it and took it off.

Dave W's Page

 

And to think back in the early 70's prostock ran nylon coated timing gears and stock chain set...