Why an engine makes more power off a burr finish

[69434]

Or here

1254366598.jpg

[user-9274568]

Let's see a pic, every company I have looked at that make sheet metal manifolds don't have a burr finish, why is that?

You have to ask them. You were the one that sold my manifold before you even tried it. So, I'd sit back and listen.

One of those photos above IS a sheet metal.

[69434]

Let's see a pic, every company I have looked at that make sheet metal manifolds don't have a burr finish, why is that?

You have to ask them. You were the one that sold my manifold before you even tried it. So, I'd sit back and listen.

One of those photos above IS a sheet metal.

Exactly, sheet metal manifolds don't have a burr finish.

Another one, no burr.

intake11.jpg

[user-9274568]

Let's see a pic, every company I have looked at that make sheet metal manifolds don't have a burr finish, why is that?

You have to ask them. You were the one that sold my manifold before you even tried it. So, I'd sit back and listen.

One of those photos above IS a sheet metal.

Exactly, sheet metal manifolds don't have a burr finish.

Another one, no burr.

intake11.jpg

There is no written law what works and what doesn't. Your posting generic photos. How do you know what a Comp manifold or Pro Stock manifold looks like? You don't..

Your point is mute.

[69434]

There is no written law what works and what doesn't. Your posting generic photos. How do you know what a Comp manifold or Pro Stock manifold looks like? You don't..

Your point is mute.

Those companies post all kinds of manifolds for every application, so I've seen a lot of them.
Pro Stock manifolds do NOT have a burr finish, wow you gotta be kidding me.
There are a few guys running your heads at my track & after they saw what my car is capable of those heads are now sitting in my engine builders shop...Hmmm

Your are stuck in your own world, if I were you I would step out of that dark box & take a look around.

[CGT]

Be nice to get this thread on track... But I am always leery of anyone that says that anything works all the time. Title of the thread, is "Why". In my opinion it should be titled "If". I dont think Flowbench testing is going to answer that question personally.

I have swapped to different manifolds on a repeatable dyno, and seen differences within the dyno's margin of error. So seeing much from a texture on the same manifold would seem unlikely, although I can see on a highly developed piece there possibly being places and areas for it to be utilized.

[69434]

Don't know there name but he was advertising your company on his back windshield.
& it's none of my business between Steve & his customers. I only talk to him about my stuff.
Like always you do your shit & I'll do mine.
We are done here!

[user-9274568]

Be nice to get this thread on track... But I am always leery of anyone that says that anything works all the time. Title of the thread, is "Why". In my opinion it should be titled "If". I dont think Flowbench testing is going to answer that question personally.

I have swapped to different manifolds on a repeatable dyno, and seen differences within the dyno's margin of error. So seeing much from a texture on the same manifold would seem unlikely, although I can see on a highly developed piece there possibly being places and areas for it to be utilized.

You know Dave Adams at Adams Automotive in Wisconsin?

[SchmidtMotorWorks]

Let's see a pic, every company I have looked at that make sheet metal manifolds don't have a burr finish, why is that?

You have to ask them. You were the one that sold my manifold before you even tried it. So, I'd sit back and listen.

One of those photos above IS a sheet metal.

Exactly, sheet metal manifolds don't have a burr finish.

Another one, no burr.

intake11.jpg

It isn't really fair to say that rough ports do not work because some people don't use them.

1. It is a lot of unpleasant, difficult, work to make them rough.
2. Human nature makes us want things that are smooth and shiny.

[CGT]

You know Dave Adams at Adams Automotive in Wisconsin?

Be nice to get this thread on track... But I am always leery of anyone that says that anything works all the time. Title of the thread, is "Why". In my opinion it should be titled "If". I dont think Flowbench testing is going to answer that question personally.

I have swapped to different manifolds on a repeatable dyno, and seen differences within the dyno's margin of error. So seeing much from a texture on the same manifold would seem unlikely, although I can see on a highly developed piece there possibly being places and areas for it to be utilized.

You know Dave Adams at Adams Automotive in Wisconsin?

No, has he done some testing on this?

[user-9274568]

You know Dave Adams at Adams Automotive in Wisconsin?

Be nice to get this thread on track... But I am always leery of anyone that says that anything works all the time. Title of the thread, is "Why". In my opinion it should be titled "If". I dont think Flowbench testing is going to answer that question personally.

I have swapped to different manifolds on a repeatable dyno, and seen differences within the dyno's margin of error. So seeing much from a texture on the same manifold would seem unlikely, although I can see on a highly developed piece there possibly being places and areas for it to be utilized.

You know Dave Adams at Adams Automotive in Wisconsin?

No, has he done some testing on this?

Call him.

Mark Dalquest, 900HP, as well.

[Olefud]

For what it’s worth. Rough finishes have a significant influence on the boundary layer. A rather fine 300 mil roughness will thicken the laminar boundary layer which, in turn, aids cohesion of the main flow to the boundary layer and underlying flow channel. This may be useful in, for instance, short side flow.
Rougher finishes may function as vortex generators that develop vortices in the boundary layer, i.e. a turbulent boundary layer that also works against flow separation. That’s what those rows of little projections on plane wings do. A turbulent boundary layer also would aid in avoiding fuel wetting the wall.

On the other hand a thicker boundary layer sops up a bit of energy and a slightly diminishes the free flow X-section. If there’s not a problem with flow separation or fuel drop out, there may be no reason to roughen. As with most techniques it’s just a tool for specific problems.

[user-9274568]

For what it’s worth. Rough finishes have a significant influence on the boundary layer. A rather fine 300 mil roughness will thicken the laminar boundary layer which, in turn, aids cohesion of the main flow to the boundary layer and underlying flow channel. This may be useful in, for instance, short side flow.
Rougher finishes may function as vortex generators that develop vortices in the boundary layer, i.e. a turbulent boundary layer that also works against flow separation. That’s what those rows of little projections on plane wings do. A turbulent boundary layer also would aid in avoiding fuel wetting the wall.

On the other hand a thicker boundary layer sops up a bit of energy and a slightly diminishes the free flow X-section. If there’s not a problem with flow separation or fuel drop out, there may be no reason to roughen. As with most techniques it’s just a tool for specific problems.

What I have found is a cylinder head with the PROPER area, the PROPER shape, doesn't respond as well. That is not a benefit in many heads.

[henny496]

This summer in the heat I went to the track with a fully smooth ported manifold I had done. I took my tools and burr marked it out in his trailer after we got a base line. Put it back on the engine, AT THE TRACK, same day, and made more runs.

ALL of my manifolds are burr marked because it works.

Hi Chad
I am not sure if I missed this somewhere, but how big an improvement did it make with the burr finish over the smooth intake?
very interesting info here
Tom

[289nate]

It sounds like the difference depends on how good or bad the port or manifold is before texturing.