Modifying stock iron intake manifold

I imagine the air can turn more effieciently, therefore creating a higher flow rate under a given vacuum. With a mild motor, I don't want to kill low end torque by dropping the center too much. I was thinking the notch would allow one side to pull from the other if needed.

 

All u need to know is in the above picture. Dont ask me any questions and I wont tell you any lies. Lol

 

You won't affect TQ, remember we have BigBlocks even if we did give up 10ftlbs you would gain more up top where it needs it more, the 350 guys have to be careful with plenum volume on the more mild builds. We need volume to add midrange and topend power.

The more volume you have the more time the mix has to atomize,straighten and get pulled in vs running into the intake floor then having to find its way to the valve, you want as much of a column of air/fuel as possible before it has to make its turn.

 

40 years ago, (man does that sound horrible). I removed the center divider on a cast iron 350 intake that had been match ported. This was way before TA Performance was even a thought. It was in the wagon, 4 speed car back then. Car was a 3 speed on the column originally. Anyway the car lost et. Came back home, welded in a divider, went back out and the car picked back up. The dual plane divider did not like being cut down to the first plenum floor. Still have that intake to remind me what not to do. Also I found that it like spacers under the carb. Tried a 2.0" open with a 1.0" adapter. Picked up up. Tried a 4 hole 2.0" on top of the open adapter picked up more. Went back to the open 2.0" lost. The 4 hole under the carb was the winner. I felt it gave the air passing through the carb more direction and reduced turbulence.
Engine is still here next door set up that way it was, only difference is it has a TA intake on it. Hasn't run since 1988

 

Got it roughed in with Angle grinder and sawz all. Now to finish with the carbide burrs and to take down the center a little. I didn't follow the curve by the divider on the secondaries.

This is kind of a hybrid between Jim and Ethan's intake. Close enough?

I'm a bit nervous about taking the center down too far. Would there be any advantage tontaking the middle divider down only in the back half adjacent to the secondaries?

 

Thoughts on something like this?

 

Tapered spacers generally always pick up power and TQ, I would at the very least knife edge or better yet bull nose the divider coupled with a spacer be it tapered,open or 4hole. I'm not aware of a Qjet tapered spacer tho

 

Round off this bottom edge of the roof of the intake where it turns out of the carb and into the runner?

 

For sure

 

FYI that spacer is upside down. And yes round off those edges.

 

Lol, good catch! I grabbed this picture off eBay.

 

Single vs. double carbide burrs?

Dang, every time I write burr, my autocorrect changes it to butt.

 

Double carbide butt for iron, single butt for aluminum

 

Two butts are better,...so I hear anyway

 

Or just call it a rotary file. More letters, less spell-check insanity.

 

Found 2 tapered :

 

That would be the way to go imo

 

My engine builder had a q-jet spacer like that, I think it was a wilson (it looked really cool), on the dyno in place of my cheap 1/2 open wood spacer it made no change in hp or torque.

Matt, cut the divider out and make a removable one in a couple of different heights, swap them out at the track and let us know what works best....

 

I have one like that but never found a difference. Maybe it's time to try my current combo.