Smooth barrel for intake

[Leatherneck]

Is it worth smoothing out the lip (1/16th) on the intake manifold where it meets the carb on a single carb setup? There is a bit of a step. Just wondering.

[Ol'fogasaurus]

Leather, I am not sure what the current thinking it but as far as port matching goes: if the intake is bigger than the head then it is the smooth fairing, up to an ~1" (or less) out fairing rule.

This is where I am not sure if I am up-to-date or not: if the intake is smaller than the intake ports on the head (up to a point) then the step is probably OK and things should flow smooth. Some (use to) like a small step to get some potential mixing benefits but again, I've not kept up-to-date with it.

Check the butterfly on the carb to the port on the intake to make sure that there is proper clearance.

Lee

[Leatherneck]

Intake and carb holes are same size. just when they matched the flange to the manifold they weren't spot on so it is off a bit. Could disrupt air flow but at my level would it be noticed?

[Ol'fogasaurus]

You would know!

Are you saying that the mounting stud's vs the holes in the carb are a tad off?

If you have to adjust then try to keep the carb and manifold in alignment. Use a small ballpeen hammer and a piece of heavy paper make a template of the carb bottom.

Put the paper on the base of the carb or manifold, which ever you are going to modify, then use the ball end of the hammer and lightly tap on the edge of the perimeter and the holes so that the paper is gut to shape. You don't have to hit hard but maybe several light hits to cut the paper.

hen adjust that before you go after removing any material.

Lee

[Leatherneck]

I suck at communicating I guess. Here, look down manifold.

intake gap.JPG

[Ol'fogasaurus]

Pictures do make things clearer.

I looked at it and saw tubes but after t was pointed out that I was lookng up then I dont
't think there is much, if any of a problem. That is the miss-match I had talked about being probably OK.

If that were the tubes of the manifyld (and I have seen them done this way before then the tubes, might be flaired out but on a second look they are not tubes.

I agree, I wouldn't worry about it as long as the butterflies are not hitting.

Lee

[sideshow]

It is larger than your venturi, I don't see how it could matter. If it was so small the butterfly was hitting it...then maybe.

[Ol'fogasaurus]

If you were going to be anal about it, if there was any problem with the side that is on the short side e.g. where they align pretty well, that is there is no step between the carb and the manifold then leave it alone. Where the mismatch is you could have some welding build up done then match things all around and fair things in smooth.

For a street rig I don't think I would worry that much. If it turned out to be a problem you could come back and fix it after it is running as well as you can get it.

Lee

[Leatherneck]

I have been running it for years like this. Just trying to get things the way they should be. Thank you for your input guys.