4412 best/worst intakes , carbs , heads etc

[mike pettit]

vdl fuel systems

[CamKing]

Many 4412 packages are designed to close the power valve at high rpm. This is done to pull out fuel and keep the carburetor from getting too rich on top yet still have enough fuel to make proper torque at lower rpm. This happens because as the engine revs against the restriction of the carburetor manifold vacuum can increase to a fairly high value and higher than the rating of the power valve which most of the time is around a 4.5. This can help power in the last few hundred rpm of operation beyond peak but it doesn't have much of an effect at the horsepower peak itself which will happen at or around 6200rpm on a 350 inch engine.

This is what we found also.
We would dyno the engine with a vacuum gauge, and look at the vacuum at the RPM the carb starts going fat on the top end, then put in a power valve to match the vacuum(3.5" vacuum=3.5 power valve)., we would then go back and re tune the carb.

As for manifolds for the 4412, the two I Like working with the most, are the Vic Jr, and the Vic Jr 2bbl.

[stockcar5]

vdl fuel systems

X2

[DaveMcLain]

Worst intake I've tested with a 4412? Weiand "tall" Xcellerator. Looks cool, runs awful.

[BigBro74]

when i wrote this i had one guy that was running the "short" 7547 weiand xcellerator on a 355. with a 1" spacer and 2bbl adapter. car seemed to run pretty well. it was in the same rule catagory as the op, probably UMP/Dirtcar SS. pretty open rules.

[raceman14]

As far as carbs go you can't beat the product and service you get from Joe and the boys at BLP. I like their and run it on a lot of applications. I like thier timing covers and a lot of their small parts.

Vanderley stuff is pretty good, I like Taco's if you can get them thru tech, and daMBest are great if you get on a development program with him. Like I have said many times before... the key to making a carburetor good is matching the fuel curve of the fuel you are running to the acceleration curve of the engine. There is 15-25RWHP in any carb if you go thru that process properly
( especially one out of the box ).

As far as manifold my preference is the Torq-Link, if they are legal it is hard to beat the killer torque and top end they make. Might be hard to find but worth it if you get your hands on one. I used them on 7448 engines with big success until they were outlawed as a non-commercially available manifold.

I also like the Super Victor with the right cam and head combination, you might give up a little on the bottom but it is tough to beat from 5000-7500rpm.

For small heads the 2B Edelbrock is a great choice and makes great torque up to 5500 and then starts falling off gradually.

I am not sure if they still make them but I had pretty good success with 2 stage power valves. I have a tool box full of the numbers I use, so I have not purchased any in 10 years or more.