1957 283/270hp dual quads drag testing on a 350

[wheezer]

Robert,
Yes the hesitation and/or bog are very evident early in the launch. Then it all clears when the acceleration decreases and high gear is reached. I'll give an update after performing the changes the forum has suggested.
I don't really think this problem could have been solved without the help from all the CLASSRACER responders. Thanks.
Tom
And oh yes,
Allan,
I have ordered the wedge plates thanks to your information and tonight I milled some wood to a 5 degree angle to install for Sunday's race to get me going. Hope to get them on tomorrow, Saturday. The metal wedges will be to late for Sunday.
thanks to all,
Tom

[55 Chevy]

Tom

Good luck with the testing & keep us updated.

Allan

[wheezer]

Update as of Sunday PM; 20 Sep 09.
Installed wedges under the carbs made of wood I milled (Moroso wedges were back ordered). Was rained out last weekend.
Today the motor ran quite poorly very much worse than before the wedges. The car launches okay then really starts running bad. This time observers told me it was puffing black smoke during the early part of the accelleration. To me, at the wheel, it almost started to miss but simply stumbled. After the acceleration slows it starts running okay at the top end about the time it is shifted into high gear.
I'm thinking the carb wedges screwed up the float/fuel level geomtery in both carbs such that something is flooding under the acceleration phase of the run. I may need to reset the floats for the wedges. Any ideas?
Oh yes I blew the rear end gears today. At least 2 weeks maybe 3 to get back testing again.

[myron ramey]

Tom,

how much wedge did you have? some manifolds have about 3 degrees made in them, it has been my experience I had to drop the float level if the angle got to steep. What intake manifold do you use ? I
also had different results with different manifolds,

Myron

[wheezer]

The tested wooden wedges are 4 degrees. The manifold is a factory stock original 1957 283CID/270HP. I don't yet know the gasket surface angle of the stock manifold.
Moroso 5 degree wedges are back ordered.

So....how much float level drop is workable?

[myron ramey]

TOM,
that manifold has no angle, and those open moroso open wedges will not work right on that manifold, I have the float settings in my notes, I will look those up, feel free to call 765-342-9746

Myron

[wheezer]

Originally Posted by myron ramey

TOM,
that manifold has no angle, and those open moroso open wedges will not work right on that manifold, I have the float settings in my notes, I will look those up, feel free to call 765-342-9746

Myron

Myron.
Not having much success contacting you by phone. Any chance you could send me a personal message with the requested help.

Also you are correct; the Moroso angle plates overhang the old manifold base giving a giant leak point. They would need to be modified to work.
Thanks

As a matter of information on the subject. A local GT class racer, Tony Cowell, advised me to reverse the front to rear bowl float settings as a starting point for my problem's solution and consider raising the fuel pressure higher than the current 4 psig I'm running.