Ported and or extrude honed HP exhaust manifolds

[Toolmanmike]

Was that one extruded? It looks a little too smooth to be a hand port.

Yes, that one was extruded.

 

[Stephen Richins]

Don't tighten the hell out of the collectors, and use the factory studs and don't overtighten them either.
I know your not overtightening them, so only tighten half of your "not overtightening".
If your headers are leaking you did it wrong......period.
Extrude hone is good money after bad.
Manifolds suck.

Not sure how this turned in to a please talk me into headers thread when my OP was asking questions about extrude honing & or porting of exhaust manifolds. I dont want headers on my car, Yes I understand headers have more power potential than anything I can do to manifolds but I don't care I'm not trying to build a race car it's a land yacht. I want the clean look & no frills of exhaust manifolds I just want to get the most out of them. So any discussion about headers on this thread is 100% pointless.

 

[Stephen Richins]

@MEV ran mid 12's in his 4 door 3700 pound NewYorker with HP's and I don't believe the manifolds were ported. What I have read on FBBO 500 hp is very doable but higher 500 hp and 600 and up is tough with HP manifolds.

that's good to know thanks

 

[Stephen Richins]

Not a V8, but still! Read: Exhaust Manifold Mod

was thinking of maybe doing extrude honing & opening up the ports & etc like in that thread it would be nice if someone did & before & after dyno test so I could decide if it's worth the effort or just leave em alone

 

[Toolmanmike]

Extrude hone video. Just the first one on the list. There's more I'm sure.

 

[70bigblockdodge]

Not sure how this turned in to a please talk me into headers thread when my OP was asking questions about extrude honing & or porting of exhaust manifolds. I dont want headers on my car, Yes I understand headers have more power potential than anything I can do to manifolds but I don't care I'm not trying to build a race car it's a land yacht. I want the clean look & no frills of exhaust manifolds I just want to get the most out of them. So any discussion about headers on this thread is 100% pointless.

I get that, but the constant bashing of headers because people gorilla tighten a 3/8" or 5/16" bolts, along the same lines tightening lug nuts up with a impact and then calling the wheels junk.
About 15-20 minutes with a die grinder with a quality bit/bits you can open up the exhaust pipe flange and smooth it and match exhaust ports to gasket will do more than extrude hone for way less money.
There is a bigger diameter exhaust flange on HP manifolds which accounts for the extra flow numbers everyone thinks they are getting from HP manifolds. Think hot gasses need more volume to escape.
There is my 2 cents take it or leave it.

 

[furious70]

You should do what he says and be done with it.

 

[CBODY67]

When I first heard of extrude honing, it was new and innovative. It also posibly put a kink in Brezinski's profits (as they were hole-sawing small block Chevy intakes and exhaust manifolds to hog them out internally, then welding it all back together to look factory, for the dirt track "factory parts" classes.

Extrude honing only follows the shapes that are already there, just makes them bigger and smoother (or to a desired smoothness). There are various grits for that purpose, just like sand paper. Key thing is that all of the internal surfaces are done, not just the easier ones to get to (which explains why Brezinski hole-sawed them to get to those places).

Past simple gasket matching, use a bore scope to look for any other internal casting flash areas that might need attention. Then determine how to get to them, as needed.

Enjoy!
CBODY67

 

[Stephen Richins]

When I first heard of extrude honing, it was new and innovative. It also posibly put a kink in Brezinski's profits (as they were hole-sawing small block Chevy intakes and exhaust manifolds to hog them out internally, then welding it all back together to look factory, for the dirt track "factory parts" classes.

Extrude honing only follows the shapes that are already there, just makes them bigger and smoother (or to a desired smoothness). There are various grits for that purpose, just like sand paper. Key thing is that all of the internal surfaces are done, not just the easier ones to get to (which explains why Brezinski hole-sawed them to get to those places).

Past simple gasket matching, use a bore scope to look for any other internal casting flash areas that might need attention. Then determine how to get to them, as needed.

Enjoy!
CBODY67

Good info thanks