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RyanUpdike70

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i have a 2200 stall and 355 gears backing my 340 471 471 lift cam and when i stall it out and lauch it just fall on it face and then takes off. What is wrong .
 
Could be any number of things Ryan, such as, when does your distributor go to full advance, should be around 2000 -2400 rpm. What carb., size and type (vacuum secondaries or mechanical) and intake manifold are you running? It could also be a fuel delivery problem. What fuel pump (electric or mechanical) are you running? By the way damn nice looking car you got there.

Need some more info. Ryan :hello2:
 
RyanUpdike70 said:
Stock intake and has a stock fuel pump and has 800cfm quadrajet vacum secodanies thanks for the you got a nice car to
Click to expand...

Right off the bat I'd say you got way to much carb on that 340 for the stall and rear gears you're running and she's going full lean when you punch it. I'd try a 650-725cfm. Lets see what the other guys think.

Terry
 
As Demon says, make sure your timing is all in at 2400 rpm @ 34- 36 degrees total. Make sure you don't have any vacuum leaks (leaky pcv hose, intake manifold gaskets, etc.) or an old wobbly distributor. Make sure none of your spark plugs are cracked, it's easy to do with headers. Check your fuel filter.

When did this start to happen? Just out of the blue? After a change? Is it a brand new engine? What do the plugs look like (and I'm talking about the insulator around the center electrode). Is it white, tan or black?

IMO a 650-750 double pumper of the Holley or Demon type would get you rolling quite nicely, but I'm a total Holley guy. I know some that can make a Carter work well, but I can't.
 
I am not much of a tec but I remember some old guys putting a vacuum box to store vacuum for that lauch problem .:eye:

Back in the old days.:drunken: But I could be mistaken :eek:ops:
 
I still think that your carb is to big for that lower stall converter. The engine is trying to come on earlier when the velocities through the carb are lower and with a large carb like the one you're running the symptons will be more pronounced than with a higher stall converter. You may also want to look a better flowing intake manifold. Also, I can't picture the operating mechanism for the secondaries on a quadrajet but trying rigging them so they can't open at all and then see if the engine still boggs off the line. They could be opening to early and if it was a Holley or a Demon it's a simple spring replace.JMO

Terry
 
I also agree with Demonseed, 800 cfm for your combination is too much carb. Your cam is just a step up from stock. A higher stall converter and a smaller carb (around 650) would be an excellent match for your 355 gears. You didn`t mention your ignition, but I would make sure you`re running a quality ignition with the timing set properly, perhaps 34* total (initial and mechanical, no vacuum included). If you want to drive the car on the street and you value your gas mileage then keep your vacuum advance. If your only concern is performance then plug your vacuum advance and get your mechanical advance set up to completely come in by 2400 rpm. Is this a 68-71 340?
 
Just an FYI, the less power or IE torque the less the convertor will flash. Even though a convertor says 2200 it may be tight and only flash to say 2k or with a lot of torque maybe 2500 or so, also they have differant ratios in the convertors too. It sounds like you may need a little more convertor or a looser one.

Good reas on this topic;
http://www.carcraft.com/techarticles/selecting_right_torque_converter/index.html

http://www.turboaction.com/conv_techtalk.html

Hope this helps? Also I would stay in the 625 AVS or AFB carb size and they the rods are easy to tune for better low end, too much air= less air speed thus= bogging at low rpms.

my 2 cents.

Good luck Ryan!
 
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