Air/Fuel experts please help

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Apr 20, 2006 | 08:12 PM

#21

MotorHead

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From: Who says "Nothing is impossible" ? I've been doing nothing for years.

I took the cap of the gas tank last night and there was no change. There is no stumble, hesitation, or miss, the power comes on from as low as 2000RPM's if I floor it with no hesitation. Even if there was a fuel delivery problem, there should be enough gas in the bowls to momentarily pull the A/F low, it goes high as soon as I go WOT.

THe car is scary fast, I don't think it is down on power. I might try different air bleeds or maybe get a pair of 100 jets for the secondary and see if that changes anything. DD dyno says I should have made close to 600HP so maybe the carb or some parts of it are too small ?

Apr 20, 2006 | 08:39 PM

#22

evil herbavore

Burning Brakes

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Im just saying if your engine is really that lean at WOT, it may be no laughing matter.

Apr 20, 2006 | 08:54 PM

#23

norvalwilhelm

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From: Waterloo ontario Canada

You talk about getting 100 jets so why not just drop the power valves in and they will automatically give you about 10 sizes bigger jetting???
Have you tried the power valves in the back?? My 850 double pumper 4 corner idle carbs came stock with 4 power valves and #82 jets all around.
Other then leaning out the idle I ended up after testing alot right back at the factory jetting.

Apr 20, 2006 | 09:21 PM

#24

MotorHead

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From: Who says "Nothing is impossible" ? I've been doing nothing for years.

FOr some reason the second power valve is not included in the two carbs I have recently purchased. They simply put in jets about 8 sizes bigger in the secondary.

The Race Demon I have, setup from the factory for drag racing only has the one power valve in the primary metering block and came with 76 primary and 84 secondary jets. It also has the progressive linkage so the secondary doesn't even open until you really have you foot in it.

I am willing to try anything, I might spend some money on a dyno tune, pretty pathetic when you think about it as I bought the LM-1 so I wouldn't have to take it to someone to set up the carb.

Apr 20, 2006 | 11:12 PM

#25

Brettmc

Safety Car

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From: St Louis MO

Keep on tinkering with it. Don't let it beat you....

Brett

Apr 21, 2006 | 09:38 PM

#26

baddZ06

2nd Gear

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http://forums.corvetteforum.com/show....php?t=1371454

Newer fuel may cause it to run a little leaner. My car seems to like 4 jets up on the front and back with an 850DP holley with a PV front and back.

Apr 21, 2006 | 11:11 PM

#27

MotorHead

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From: Who says "Nothing is impossible" ? I've been doing nothing for years.

Interesting, the Sunoco 94 I use is 10% ethanol. Someone mentioned high speed air bleeds, I might fool around with those a little

Apr 22, 2006 | 06:26 AM

#28

BigBlockk

Drifting

Joined: Sep 2004

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From: North Bend Ohio

Quote:

Originally Posted by MotorHead

Interesting, the Sunoco 94 I use is 10% ethanol. Someone mentioned high speed air bleeds, I might fool around with those a little

Air is used as a break on fuel flow. If it didn't have air bleeds the mixture would get richer and richer as air flow through the carburetor went up. Tunable air bleeds can make a carburetor a very accurate fuel mixer. The Holley design needs all the help it can get.

BigBlockk

Later.....

Last edited by BigBlockk; Apr 23, 2006 at 05:59 AM.