Extrusive Honing on Cast Manifolds

[VANDAN]

I'm putting together an engine using Cast Exhaust Manifolds, Max Wedge to be precise, as I want the build to have that look. I know I could get better flow with a set of headers, but was wondering if anyone has tried "extrusion honing" on a set of these ? I was hoping to smooth and increase the flow somewhat, and possibly lighten them weight-wise also. Any F.A.S.T. Racers, or anyone elses input is welcome...Thanks

 

[gkent]

I've heard filling them with muriatic acid is a hot trick used by FAST guys. Extrude hone would probably be a very expensive proposition.

I think the trick would be to block the head flanges and fill with water and measure the volume. Then do the acid thing and then compare.

Even if you don't do the acid method, it would be beneficial to measure the volume before and after

 

[EARLY B]

I'm putting together an engine using Cast Exhaust Manifolds, Max Wedge to be precise, as I want the build to have that look. I know I could get better flow with a set of headers, but was wondering if anyone has tried "extrusion honing" on a set of these ? I was hoping to smooth and increase the flow somewhat, and possibly lighten them weight-wise also. Any F.A.S.T. Racers, or anyone elses input is welcome...Thanks

Someone was selling the manifolds cast out of aluminum, saw them on Ebag.

 

[62MAX]

I'm putting together an engine using Cast Exhaust Manifolds, Max Wedge to be precise, as I want the build to have that look. I know I could get better flow with a set of headers, but was wondering if anyone has tried "extrusion honing" on a set of these ? I was hoping to smooth and increase the flow somewhat, and possibly lighten them weight-wise also. Any F.A.S.T. Racers, or anyone elses input is welcome...Thanks

Do a search on Moparts and you will find many responses,most agree that results are minimal for what it takes to do them.

 

[Photon440]

A FAQ page from Extrudehone http://www.extrudehoneafm.com/faqs/faq-automotive/

 

[big_shmoop]

I was thinking the same, but my research lead me to find most found little to no difference. In the end it's just not worth the cost.