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I am gathering parts for my latest engine. Hi perf yet streetable 292 to go into a 53 chev. I acquired a side draft manifold that takes three Weber DCOE carbs. I have scrounged the internet and bought three 45 DCOE's in my price range. Two are matching and one isnt. What I need now is some good info on the basic tune for running these on a 292. Buying six of every part... everytime I make a change... to dial these carbs in can get pricey so having a good starting point is a must! These are the items I am looking for... Venturi size # Aux Venturi # Emultion tube # Main Jet # Air Corr Jet # Idle Jet # Pump Jet #
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The best place for that tech information may be Inglese Induction 866-450-8089 or http://www.inglese.com ,because there is more factors too like cam timing (you need a zero overlap). Since Mickey also sold Total Performance to Speedway I don't know how to contact him, he was a wealth of info on these carbs.
'45 Ford PU 66 Valiant wagon, leaning tower of power. 79 Chevy C10 w/250 02 PT Cruiser Convertable
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I really don't know anything about sidedrafts...but, welcome to Inliners!
And where in Wisconsin might you be?
Just curious...
-Sam.
1967 Chevy II, 2-door post. 250, 3-OTT.
1969 GMC 1/2-ton. 307, 3-OTT. DD.
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you need a zero overlap
Can you name an engine built since 1930 that has zero overlap?
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There have been a bunch of books written about tuning webers...there is a reason why they were (are) so widely used. Check a used book site like Alibris…these carbs can be tuned to handel almost any situation. Think of racing Ferrari's or 25 horse power tiny Fiats.
Leif
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Hi guys... thanks for the responce.
To clear up one point, I am building this engine for a good friend. I have been building HP engines since the early seventies... with everything from carbs to injection but except for one AC Cobra I have no experience with Webers.
I have read books on tuning DCOE's but none I found had a good starting point. Since the chev 6 has two intake ports sharing one carb I cant use any existing setups I found.... a example would be the Jag XKE, 4.2 litre six cyl but with out common intake ports.
My friend has a limited budget so I am hoping to find a good starting point.
Last edited by ottoman; 05/04/09 03:28 PM.
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find a jag inline that has similar displacement and use that as a starting point.
Tom I.I. #1475
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Since the chev 6 has two intake ports sharing one carb I cant use any existing setups I found.... I've used (3) sidedraft Webers on many 250 and 292 race engines before, and the siamese port configuration was never an issue with any of those engines. Several of the 292's were at the 550 HP level....
Class III CNC Machinist/Programmer
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I don't have a horse in this race, because I don't know Webers well enough to give you actual numbers. There's plenty of information on line about selecting these parts based on engine size, RPM, VE and throttle diameter. My 1st choice: http://www.teglerizer.com/dcoe/webertune.htmHowever, there's no way you can finalize the tune on these without the motor already done - that includes air cleaners, cam timed in place, ignition advance and curve, full exhaust system. All you're going to get from Clifford or anyone else is something good enough to start, idle, have some response and not do any damage. On that basis, Webers are worse than Holley 350s. They're not magic, it's the really precise tuning that develops the extra power. If you cannot, will not chase down that last flat spot you're throwing money away for something to tell the guy on the next bar stool.
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ottoman-
Choke 36 Emulsion tube F2 Main jet 140 Air Correction jet 190 Idle Jet #5559 Pump Jet 45 Accelerator pump circuit discharge valve 40
This is for 3 - 45DCOE carbs on a 292 with lump ports, cam, Pertronix.
Hope it helps.
Will Willis
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The F2 is pretty universal, many of the other sizes are functions of the choke size, of each other, or both. You could go larger than 36, but unless the head is done well it won't do much. A stylish air cleaner will throw the whole thing overboard - even some of the most expensive are worthless. You need a large filter area (square inches), but also the cover is way too close to the air-horn in many of them, should be at least 3" away for my taste (the usual rule is twice the air-horn ID; 45mm × 2 = 3.54"). Too close not only restricts air entry, but also causes a signal reflection off the cover that confuses the venturi and emulsion tube.
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Panic: A follow-on question.. Is it safe to assume the air cleaner applies to all carbs? For instance Carter YH's... Taller air cleaner is preferable?
Thanks: Paul...aka xerxes
Last edited by Xerxes; 05/06/09 02:13 PM.
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Yes, "pancake" simply does not work. The effect differs widely between carbs and between engines for different reasons, but to make the air cleaner housing transparent to the venturi (on/off has no effect) it should be big. There should also be radial space around the air-horn to about 2.5 × the ID (45mm needs 4.4") so that any wave pulse is completely exhausted inside the housing and doesn't echo off the inner walls.
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ottoman -
p.s. You might want to substitute a 150 main jet due to altitude.
Will Willis
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12 port SDS EFI
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ottoman-
Choke 36 Emulsion tube F2 Main jet 140 Air Correction jet 190 Idle Jet #5559 Pump Jet 45 Accelerator pump circuit discharge valve 40
This is for 3 - 45DCOE carbs on a 292 with lump ports, cam, Pertronix.
Hope it helps.
Will Willis Thanks.... Thats what I was looking for... a good starting point
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