Why an engine makes more power off a burr finish

[BradH]

I would be happy to do more burr finishes it saves me so much time.

From what I've seen looking at pics of Larry M's and Chad S' work, there's a pretty big difference between what they're doing to apply a specific textured finish vs simply skipping using sanding rolls after leaving a basic cuttered surface.

I'd be interested in whether either of them consider what they're doing a "time saver"...

BTW, I did watch your video and found it very interesting. Are you planning on a series of them, or is it more a case of when something comes to mind that you think is worth the time to produce? Thx - Brad

[WeingartnerRacing]

I would be happy to do more burr finishes it saves me so much time.

From what I've seen looking at pics of Larry M's and Chad S' work, there's a pretty big difference between what they're doing to apply a specific textured finish vs simply skipping using sanding rolls after leaving a basic cuttered surface.

I'd be interested in whether either of them consider what they're doing a "time saver"...

BTW, I did watch your video and found it very interesting. Are you planning on a series of them, or is it more a case of when something comes to mind that you think is worth the time to produce? Thx - Brad

When things come to mind. I really don’t have a lot of time to do more extensive ones.

[SpeierRacingHeads]

I don't do it as a "time saver" That thinking is skewed.

People have no idea what others do in the name of power.

PS. 5hp..

But let me get this straight. One of the biggest talkers on burr finish just said 5hp, saves him 4 hours. 4 hours is money to the customer. And yet we are debating it. Saves money, and maybe worth 5 hp. And we are debating it. WOW.

Even if it makes 5 hp less.. 4 hours is money to the customer.

What EXACTLY is the problem? Some well known people defend it and it ruffles feathers. BINGO.

[1980RS]

Well after seeing some of the pictures of the burr work you do Chad, it inspired me to try that a couple of years ago and try it out for myself. Last year at the track I ran the intake and heads that I did on my peanut port engine and after the race I swapped out the intake for a dual plane (testing purpose only). I have to tell you, not only was I happy with the way it ran, the intake and ports were the cleanest looking ever with the burr finish. I really want to thank you for putting up pictures for all to see of the work that you do, it is much appreciated.

[ClassAct]

Well after seeing some of the pictures of the burr work you do Chad, it inspired me to try that a couple of years ago and try it out for myself. Last year at the track I ran the intake and heads that I did on my peanut port engine and after the race I swapped out the intake for a dual plane (testing purpose only). I have to tell you, not only was I happy with the way it ran, the intake and ports were the cleanest looking ever with the burr finish. I really want to thank you for putting up pictures for all to see of the work that you do, it is much appreciated.

Chad and Larry Meaux are the two biggest influences in my 10 year, on and off effort to develop the technique of a burr finish, and I *THINK* I’ve finally got it. And if it’s not exactly correct yet, I’m dang close.

We’re it not for those two, and Darin Morgan giving his thinking on it I’d have NEVER a considered a burr finish.

[SpeierRacingHeads]

You guys are dead on and it's never talked about. How clean the ports are and how clean it revs...

Glad I was some type of influence, that makes me happy! Makes some of the grief worth it.

THANKS!

[David Redszus]

You guys are dead on and it's never talked about. How clean the ports are and how clean it revs...

Glad I was some type of influence, that makes me happy! Makes some of the grief worth it.

THANKS!

Chad
Why do you think the ports are cleaner?
Does that apply to port injected engines as well?

[1980RS]

You guys are dead on and it's never talked about. How clean the ports are and how clean it revs...

Glad I was some type of influence, that makes me happy! Makes some of the grief worth it.

THANKS!

You're welcome.

[Leftcoaster]

Chad
Why do you think the ports are cleaner?
Does that apply to port injected engines as well?

Does the distance between intake manifold port injector and clean wall surface remain constant regardless of injector to intake valve distance - - and do the manifold runners and ports of direct injection engines remain clean throughout the tract?

[Erland Cox]

Direct injection engines usually clog the ports with sludge from EGR.
No fuel to wash that away.
Cleaner ports must mean more boundary layer action.
I have seen it in jetting and accelerator pump. The coarse finish needs less of both.
So there is less wall wetting with a coarse finish. And that should lead to less chances of wetting the plugs.

Erland

[SpeierRacingHeads]

Direct injection engines usually clog the ports with sludge from EGR.
No fuel to wash that away.
Cleaner ports must mean more boundary layer action.
I have seen it in jetting and accelerator pump. The coarse finish needs less of both.
So there is less wall wetting with a coarse finish. And that should lead to less chances of wetting the plugs.

Erland

Exactly what I have seen. Less jet and accelerator pump! Some guys are perplexed because they need to take jet out. But my though on that is most manifolds are restricted and you have to fatten them up to feed the restricted runners. Even ported I've seen some manifolds nasty inside, we all have.

I have seen no difference burr or smooth with an EFI engine. We did a lot of testing with the EMC engines. My personal street engine is EFI and I burr finished the manifold.

[SpeierRacingHeads]

I know it's just a video. This is my street engine. EFI with a elbow and 58mm TB. 44lb injectors with a Motown burr finished manifold.

https://www.youtube.com/watch?v=4R-Hvm7 ... PCU6K0upEg