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PostPosted: Mon Aug 13, 2012 2:16 pm 
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Turbo EFI
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Joined: Fri Dec 30, 2005 2:49 pm
Posts: 1152
Location: Houston, TX
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I've done some searching and there's been plenty of discussion on this carburetor, but very little mention of what size jets anyone is using (that I could find). I'd love to at least have a good starting point. Reading up on tuning these Webers is making my brain hurt.

The standard jet kits you see on the internet for 6-cylinder applications include the following:
Mains (150,155,160)
Primary Idle (75,80,85,90)
Secondary Idle (60,65)
Pump Jets (60)
Air Corrector (160,180,190) [or (180,190,200) from a different supplier]

What's the application, you might ask? Well, after my '64 Dart (225) sat for 3 years, it's finally being resurrected as a LeMons racecar. I'm sure some of you are familiar with this, but it's basically endurance racing for "cheap" cars. As such, I'm not really concerned about fuel mileage as I am about performance. That being said, it's endurance racing, not drag racing.

I'm really hoping that the jets I currently have in the carb are appropriate (or close), because the LeMons requirements drastically limit your budget and the jet kits are going for $60. I don't know what jets my carb has at the moment, but I suspect they are on the smallish side. IIRC, the previous owner was using it on a 4-cylinder. I'll be tearing the Weber apart this week to check if it needs a rebuild kit, so I can hopefully find that out as well.

I also found in my searching of this and other forums that I need a fuel regulator. That may have contributed to the problems I had with this Weber in the past.

Finally, what is the purpose of the "Power Valve"? Some folks on a different forum were talking about disabling it if you're not concerned about fuel mileage. I don't know if that would be worth the trouble or if it would just be really stupid in general.

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
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PostPosted: Mon Sep 10, 2012 8:25 am 
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Turbo EFI
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Joined: Fri Dec 30, 2005 2:49 pm
Posts: 1152
Location: Houston, TX
Car Model:
I've finished rebuilding the Weber, and what a mess it was. Varnish everywhere, fuel passages clogged, everything rubber reduced to garbage. Anyway, it's all cleaned out now with new accelerator pump, power valve, needle valve, gaskets, etc. I also checked my current jet sizes:

Main: 140/137
Air: 160/170

So it's definitely set up for a 4-cylinder. I don't know why the secondary main jet is smaller. In every case I've read on various websites, people have used a larger main jet for the larger secondary venturi. Upon further search, I actually did find one example of jet sizes posted on this forum from someone (I forget who) running a 32/36 DGV on a 225:

Main: 150/190
Air: 170/180

The good news is that the 225 fired right up after I got the bowl filled; the bad news is that it won't stay running. It will idle for about 2 seconds before cutting out, both hot and cold. It won't stay running at any constant RPM; the only way to keep it running is to continually goose the throttle. As a side note, the electric choke appears to be working, which is good news considering I didn't disassemble it.

I am confused by one thing: many years ago, I drove the car with no problems using this exact same carburetor and the same jets. The difference is that back then, I had it connected with one of those cheesy 2-into-1 adapters on top of the stock 1-bbl manifold. Now I have it connected to a proper Super Six manifold via a custom adapter plate.

My theory is that, when I was using the 2-into-1 adapter, I was restricting the airflow to an extent that the smaller fuel jets were acceptable. Now that I'm actually pulling the right amount of air through it, the jets can't put out enough fuel. Or is my understanding completely wrong?

Also, back when I first installed this carb on the super six intake (before the car sat for 4 years), I noticed that the engine actually ran well enough to drive (sort of) if I held the choke closed while the engine was hot. At the time, I thought this pointed to a vacuum leak somewhere, but now I'm thinking it was a result of the jets being too small. Either one of those problems would cause a lean condition, right?

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing


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PostPosted: Mon Sep 10, 2012 2:58 pm 
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Turbo EFI

Joined: Sat Feb 20, 2010 10:23 am
Posts: 1321
Location: N. Ga.
Car Model: 64 Valiant
Sounds lean if taking air away from it makes it run better. I have with Webers some, both sidedraft and these type you have.Put a bigger gas jet in it and see if that improvrs it.

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 Post subject: Weber 32/36
PostPosted: Sat Oct 20, 2012 1:41 pm 
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TBI Slant 6

Joined: Wed Feb 20, 2008 5:38 am
Posts: 202
Location: Medical Lake, WA
Car Model:
The 2 in 1 bbl adapter is pretty much worthless, spend a few $$ and get a super six setup and the adaptor. Having a smaller secondary main is ok since you should be moving much more air with the secondary open...however, a wideband O2 meter will tell you all you need to know. Plan on spending some money on jets and just take good notes as you rejet

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