Gear drive settings.
Thread Starter
Drifting
Joined: May 1999
Posts: 1,610
Likes: 3
From: Goulburn, Australia NSW
Gear drive settings.
While I'm replacing my 350 sb harmonic balancer, I thought that while I'm at it I might as well put the Pete Jackson gear drive in as well. This motor will only be in the car until next year so I thought I'd find out now whether I like the gear drive or not now.
Anyhow the question I have is regarding the offset buttons that install into the cam drive. The engine and cam are I presume completely standard so which degreed offset button should go in..... 0-2-4-6-8? Anything else I should be aware of while putting this together?
Any help would be greatly appreciated Thanks.
Bob
Anyhow the question I have is regarding the offset buttons that install into the cam drive. The engine and cam are I presume completely standard so which degreed offset button should go in..... 0-2-4-6-8? Anything else I should be aware of while putting this together?
Any help would be greatly appreciated Thanks.
Bob
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: Gear drive settings. (Brutus)
Zero, keeps you where you are supposed to be. You will never know for sure unless you degree the cam, both before and after. Generally, advancing the cam shifts the torque peak to slightly lower rpms. Retarding ing it raises the point of the peak. Actually, the peaks aren't likely to change, but the curve will rotate around the peak point, "fattening" the area under the curve either above the peak or below it, as outlined above. If that isn't explained, clearly, just remember that advancing the cam "favors" lower speed performance, while retarding augments at higher rpms. With no more details, *I* wouldn't deviate more than 4*, one way or the other. Good luck, and...
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Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Gear drive settings. (CFI-EFI)
I have not setup a Pete jackson myself. But the local Sprint cars all use gear drive single idler units. When you install any gear drive one of your concerns is the gear slop or lash. Those numbers are used to insure accurate cam & dist/Mag timing.
So if you were to set the crank at Zero and cam at Zero timing. The gear drive might have to be at say 2 or 4 degrees because of the slop in the gears meshing. :) Bob don't quote me because I only saw it done. With the cam installed at Zero and held ridged The gear drive in place at it's Zero setting and a degree wheel on the crank shaft. Rotate the crank and see how far it moves when it takes out the systems slop.
With time the gears also ware and you might have to put in addition advance. That's why it goes clear up to 8
So if you were to set the crank at Zero and cam at Zero timing. The gear drive might have to be at say 2 or 4 degrees because of the slop in the gears meshing. :) Bob don't quote me because I only saw it done. With the cam installed at Zero and held ridged The gear drive in place at it's Zero setting and a degree wheel on the crank shaft. Rotate the crank and see how far it moves when it takes out the systems slop.
With time the gears also ware and you might have to put in addition advance. That's why it goes clear up to 8
Thread Starter
Drifting
Joined: May 1999
Posts: 1,610
Likes: 3
From: Goulburn, Australia NSW
Re: Gear drive settings. (WashingtonRacer)
v
I've decided to go with the 2 deg button so hopefully this won't give me any problems. So far, so good. Just getting the crankshaft gear off now.
Bob
Thread Starter
Drifting
Joined: May 1999
Posts: 1,610
Likes: 3
From: Goulburn, Australia NSW
Re: Gear drive settings. (Brutus)
Well it's all come to a screaming halt! :mad The idler gears just wont go on! The only way I can get them to fit is to remove the degree buttons altogether which I don't think would be a good way to run the engine somehow. :rolleyes:
Of course there's a little note in the instructions that says if there's not enough clearance in the reverse idler gear then just give them a call about an undersized idler gear. Big Deal!!..... that's no bloody help to me all the way over this side of the pond. My only recourse now is to take everything off and put a timing chain back on. The only fortunate part is that I have a new set laying around here, but that still doesn't ease my anguish. :mad :rant:
Thanks for everyones help anyhow. It was good while It lasted.
Bob
Of course there's a little note in the instructions that says if there's not enough clearance in the reverse idler gear then just give them a call about an undersized idler gear. Big Deal!!..... that's no bloody help to me all the way over this side of the pond. My only recourse now is to take everything off and put a timing chain back on. The only fortunate part is that I have a new set laying around here, but that still doesn't ease my anguish. :mad :rant:
Thanks for everyones help anyhow. It was good while It lasted.
Bob
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: Gear drive settings. (Brutus)
Now, that's a bite in the... Don't you just love modifying things? Has the block ever been line bored? There are even "special" timing spocket and chain sets, for just that situation. Are you going to have them send the right parts for later, or do you plan to stick with the chain? Good luck, and...
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Drifting
Joined: Jul 2001
Posts: 1,897
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From: La Fontaine Indiana
Re: Gear drive settings. (Brutus)
I have never used the gear drive but we have an automotive machine shop near me that builds engines for sprint cars and drag cars and they will not install the Pete Jackson gears they just refuse to do it.
Thread Starter
Drifting
Joined: May 1999
Posts: 1,610
Likes: 3
From: Goulburn, Australia NSW
Re: Gear drive settings. (black bart)
I have never used the gear drive but we have an automotive machine shop near me that builds engines for sprint cars and drag cars and they will not install the Pete Jackson gears they just refuse to do it.
Race Director
Joined: Nov 2000
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From: Waterloo ontario Canada
Re: Gear drive settings. (Brutus)
Brutus I did a peter jackson gear drive on my mustang 3 or 4 years ago and there was a problem but it didn't take that much to correct. The trouble was I can't remember what the problem was.
I just remember it needed something. I will talk to my son tomorrow and hopefully his mind is better then mine but it was something simple to make it fit.
Don't give up yet. I ran the noisy one and it sounds like a blower under the hood.
I just remember it needed something. I will talk to my son tomorrow and hopefully his mind is better then mine but it was something simple to make it fit.
Don't give up yet. I ran the noisy one and it sounds like a blower under the hood.
Thread Starter
Drifting
Joined: May 1999
Posts: 1,610
Likes: 3
From: Goulburn, Australia NSW
Re: Gear drive settings. (norvalwilhelm)
Thanks Norval. I have managed to finally get the gears fitted now at long last, but you wouldn't believe it......after all this effort I forgot to install the cam button! :rolleyes: Now I have to go back in there and put the button onto the end of the cam gear. The sheer relief at getting the gears to fit made me overlook the button. I'm hoping I can just unbolt the timing cover and slip it in place without having to remove the harmonic balancer again.
Btw I got the noisey one too. If I can't have a blower just yet, I'll settle for the sound of one.
Bob
Btw I got the noisey one too. If I can't have a blower just yet, I'll settle for the sound of one.
Bob
Race Director
Joined: Nov 2000
Posts: 11,872
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From: Waterloo ontario Canada
Re: Gear drive settings. (Brutus)
I'm glad you got it to fit. Like I said it didn't just fall in for me either but with a little help it fit fine and continues to give that blower whine.
Have a nice day Brutus and good luck on installing the cam button.
Have a nice day Brutus and good luck on installing the cam button.
Le Mans Master
Joined: Apr 2000
Posts: 7,562
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From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Re: Gear drive settings. (Brutus)
I've heard that some people shy away from gear drives because they can create harmonics that can fatigue other engine parts. Has anyone else here heard this :confused: .
