Need Help with Hartman Dual Carburetor Linkage

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Jeff Troy
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Need Help with Hartman Dual Carburetor Linkage

Post by Jeff Troy » Fri Jun 29, 2007 10:32 pm

Hi, Guys,

I got one of those dual carb linkage sets from Mike on eBay. Looks like great stuff, but I'm not quite sure how it all goes together -- or even if it will go together with my two small-bore Tillies and a Reed Enineering Manifold, the one that puts one of the carbs on a slightly tilted back angle.

Can anyone refer me to a drawing of the installation, or send a link or drawing to jefftroy@aol.com, or perhaps fax a rough sketch to 717-293-1031?

I'd surely appreciate the help.

Thanks and warmest regards...
Jeff Troy
759 New Holland Ave.
Lancaster PA 17602
717-917-3670 (Leave message and I will return your call)
http://www.bradleygt.com
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ted johnson
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Re: Need Help with Hartman Dual Carburetor Linkage

Post by ted johnson » Fri Jun 29, 2007 11:23 pm

Jeff, I can tell you that the carbs need to be parallel, mounted on the same base plane, and the back-to-back spacing is the same as the GEM V-12 dual manifold top. Can't remember the numbers, and I don't have a V-12 top to measure.. The gears mount by tapping the existing holes on the throttle bellcranks to #5-40. Good luck! Ted

Rob Voska
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Re: Need Help with Hartman Dual Carburetor Linkage

Post by Rob Voska » Sat Jun 30, 2007 7:28 am

I don't think gear drive will work with this manifold. Get ahold of some old mags and I'm sure you can find a picture. Lots of times they pulled one carb with a short rod (coat hanger / welding rod) to pull the second carb.

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Dan Flanders
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Re: Need Help with Hartman Dual Carburetor Linkage

Post by Dan Flanders » Sat Jun 30, 2007 1:34 pm

Hi Jeff-
Here are some pics I took of Tom Smith's dual-carb set up... It is absolutely one of the cleanest I've seen, so much so I took about 25 pics to remind me how to set it up and what a good set-up looks like. Maybe you can get some ideas from this for your application. Post some pics with the results.

Dan
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Rob Voska
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Re: Need Help with Hartman Dual Carburetor Linkage

Post by Rob Voska » Sat Jun 30, 2007 7:51 pm

Wrong manifold but a variation should work for Jeff.

Jeff Troy
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Re: Need Help with Hartman Dual Carburetor Linkage

Post by Jeff Troy » Sun Jul 01, 2007 11:44 am

Thanks, Guys,

That picture will help me do a better job than I've been. Leave it to Tom to come with an effective solution for almost anything. Thanks, Dan (and Tom).

Also, thanks for letting me know that the Hartman linkage won't do my Reed manifold. Better to know before wasting hours trying to do what cannot be done.

The Blitz is still in the painted and ready-to-assemble stage. I'll post pics of the linkage and everything else when it's done.

See you in Fremont.

Thanks again, and warmest regards...
Jeff Troy
759 New Holland Ave.
Lancaster PA 17602
717-917-3670 (Leave message and I will return your call)
http://www.bradleygt.com
http://www.jefftroy.com (Under Construction)

Tom Smith
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Re: Need Help with Hartman Dual Carburetor Linkage

Post by Tom Smith » Sun Jul 01, 2007 4:17 pm

Jeff, That linkage configuration is what Mick Rupp used on his kart, I just replicated it for the reasons Dan pointed out.
I think the best feature is not having a flexable cable between the throtle arms.
I set the linkage making sure both butterflys fully close with the idle screw backed off. That way when you come off the throtle you get a good rich mix ingested. I also set the throtle stop on the pedal control rod so the butterflys are almost but not quite fully open when the pedal return sping coil binds.
BTW I've seen engines with more carburation than needed (Marios' Ford Cam Am engine for example) produce peak power at about 70% throtle opening instead of full throtle and at full throtle the excess fuel (standoff) just blows back out the intake stacks. Karts too, Tom

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Re: Need Help with Hartman Dual Carburetor Linkage

Post by Dean Seavers » Mon Jul 02, 2007 6:26 pm

Tom-

Does EC sell the long blank throttle shafts that you use on your setup, or did you have to fab those? Trick deal!

Thanks,
Dean

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Dan Flanders
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Re: Need Help with Hartman Dual Carburetor Linkage

Post by Dan Flanders » Sun Jul 08, 2007 10:01 pm

Here are some pics and commentary on the carb set up Tom forwarded....Great Stuff Tom! Thanks for sharing it.

"...here are a couple of pics of Big-Js' karts
with the same carb linkage I like to use. The 2 Purple
Lancers are '66 Lancer Team karts which at that time
were Rupp Lancers. Rupp built the karts and Big-J made
the engines and aftermarket stuff at that point. The
guy that looks half dead laying against the B-open
Lancer is Lancer Team driver
Ken Burden, the best C-open Lancer driver ever.
I love those brand new beautiful Big-J 820s on that
Chap. Talk about period correct? This was at the
nationals that year in Barnsville, GA."
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