Weber Carb Gears

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John Vardanian
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Weber Carb Gears

Post by John Vardanian »

I have a broken shaft gear on my 36DCL. This is the quarter gear that meshes the two throttles. Any idea of a good source for these? Thanks.

john
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DWR46
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Re: Weber Carb Gears

Post by DWR46 »

John: Start with Mike Pierce. I does seem like somebody remade these sector gears at some time.
Dyke
John Vardanian
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Re: Weber Carb Gears

Post by John Vardanian »

Thanks Dyke. I found out these vary from DCL to DCS. On the DCS the gear rides directly on the shaft, whereas on the DCL the gear rides on an eccentric bronze bushing. Why eccentric? It's so you can adjust the gap between the two gears.

Image

john
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kare
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Re: Weber Carb Gears

Post by kare »

What material is that? Zamac? It might be possible to weld it back together with Alutight or an equivivalent. Haven't tried it on Zamac yet but they say it works. How does that piece connect to a shaft? Is there a collar that ties it down? Does it do its job as is or is there a functional problem with a broken lip? Should I come up with more questions?
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tyang
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Re: Weber Carb Gears

Post by tyang »

weberdcz6_2.jpg
weberdcz6_2.jpg (185.07 KiB) Viewed 11960 times
Here's a picture of the clamp that secures the shaft to the gear. it ties the two throttle plates together to synchronize the two barrels of the carb.

Sorry about all the arrows, but I'm working on an article on how to strip a DCZ6 for general service and cleaning.

Tom
'63 330 America #5053
John Vardanian
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Re: Weber Carb Gears

Post by John Vardanian »

Thanks Tom. Which type is that? Also, who do you use for rebuilding Webers.

Can someone tell me whether the 36DCL body should be black or unfinished? Thanks.

john
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DWR46
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Re: Weber Carb Gears

Post by DWR46 »

DCL's were originally painted Black by Weber. They are made of an aluminum alloy, and not the later (and cheaper) Zamac alloy used in the DCZ.
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Re: Weber Carb Gears

Post by Steve Meltzer »

I'm not sure who else is expert in rebuilding these, but the name that always comes up is Mike Pierce at Pierce Manifolds (408-842-6667). The previous owner of my GTC had them rebuild the DCZs on the car. Since then, my dealings with them has always been first rate: they're very knowledgeable, have all the parts and are very friendly. I've talked to Mike on a number of occasions and he's always been happy to answer my questions, even when there was no purchase involved. (I always end up buying something however!) Best of luck. steve
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tyang
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Re: Weber Carb Gears

Post by tyang »

Pierce seems to be the best place to send your carbs if they need a complete rebuild which would include new throttle shafts and straightened base plates. Both of these processes that Pierce offers are pretty involved, and is probably best left to them since that's all they do, however, many times a carburetor only needs a thorough cleaning to show great improvement in performance. The residues left in the bowls (as Steve has struggled with in the form of rust) can clog up passageways internally that can be cleaned out yourself. The biggest problem we've found is a white residue from evaporated gasoline that can easily clog a small orifice. Disassembling the carb, cleaning it in carb cleaner, washing everything out thoroughly, and reassembling is something that can be done without a complete rebuild. I'm working on a description of my process, and will try to get it posted soon. It'll be a good addition to how to tune the carbs once they're cleaned and assembled.

Tom
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John Vardanian
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Re: Weber Carb Gears

Post by John Vardanian »

Dyke, Tom and others in the know, one of my carbs has too much gear lash. It is the adjustable kind (36DCL) and I got the adjustment to the point where at full throttle I have some miniscule binding, and even then there is too much lash at the bottom range. If I pick up the lash any more, there will be more biding at increased throttle and may result in breaking one of the gears. I verified this condition by having a pair of suction meters on the carb and upon opening the throttle, I can see the marked delay in the secondary. I called pierce, Weber America and a few lesser shops and these sector gears are no longer available. Any thoughts, or interim remedies? Thanks.

Has anyone tried cutting a close enough pair of spur gear and making their own sector gears?

Oh, and the bottoms are quite straight and there is zero warping.

john
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Re: Weber Carb Gears

Post by DWR46 »

John: Your lash adjustment seems about right. You want to be as tight as possible without any binding. What I think you are not doing correctly is synchronizing the carbs.

1. Get all three primary barrels synched (the ones with the linkage rod attached).

2. Synch the secondary barrels ( the ones with the sector gear and clamp) to the primaries. Tighten the clamp and then loosen the idle speed screw on the secondary barrel until it no longer touches the carb throttle shaft (Ijust back it off one turn). This takes all the "play" out of the sector gears. You will probably find that the secondary barrel has "gone out of synch" by the amount of the play and it will show lesser air flow than the primary barrel.

3. Now screw the idle speed screw for the secondary back in the one turn, loosen the clamp and then raise the secondary barrel a small amount (enough to compensate for the "play" in the sector gears. Then tighten the clamp, back off the idle speed screw the one turn and see how close your synchronization is. It will usually take two or three trys to get each secondary barrel synched to the primary barrel with the secondary idle screw backed out the one turn. However, when you are done, the secondary barrel will open in perfect unison with the primary barrel (as the "play" will be eliminated) and they will also be synched together.

4. When you are completed, the engine idle speed is controlled with the primary idle Speed screw only. In other words, on a three carb car, only the screws on one side of the engine are used to set the final idle speed.

If this is confusing, find me at the Monterey Historic Races either weekend. Look for the gray and black transporter with TAM on it.
John Vardanian
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Re: Weber Carb Gears

Post by John Vardanian »

Dyke, as always, thanks. I have followed your 1970's article but I think there may be something in you #3 paragraph (above) that I have overlooked. I will confirm again tomorrow.

Hope to see you in Monterey at Tom's party. Will you be at the track during the weekend prior to the main event, the "prehistorics". I'm going to come by in my PF coupe on Sunday (8/12), and if I get to park in the paddocks, I'll have you look at my beauty.

john
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kare
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Re: Weber Carb Gears

Post by kare »

John Vardanian wrote:Has anyone tried cutting a close enough pair of spur gear and making their own sector gears?
Do you wish to repair the damaged one or remake a whole set? How about drilling and inserting a brass insert?
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Re: Weber Carb Gears

Post by 330GT »

John Vardanian wrote:... I called pierce, Weber America and a few lesser shops and these sector gears are no longer available. Any thoughts, or interim remedies? Thanks...

john
You might try http://www.dellorto.co.uk. They had the sector gears for the 40DCL carbs in my PF coupe. Mike Pierce only had 2 and they were NLA from Weber. I also looked into having some cast and Mike was interested in buying some if I had gone that route.
Regards, Kerry
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DWR46
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Re: Weber Carb Gears

Post by DWR46 »

John: As to my current carb tuning methods, my level of knowledge is a work in progress. I know a lot more now than I did 35 years ago. What I wrote then reflected my level of expertise at that time. Since then I constantly learn more with each car I work on, and exposure to different marques also brings new solutions to old problems.
My book then may not have addressed the issue of taking the "lash" out of the gears.
We will be at the Pre-Reunion.
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