Cast iron intake/exhaust manifold porting??

Turboomni

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Maybe a long shot but was wondering if this has been done with any real success .
Not just port matching which is easy enough but actually opening up the interior a bit. In some searches I have seen Extrude honing and acid being poured into the manifold but I think the latter was mostly for cast iron exhaust manifolds. Both techniques are rather indiscriminate in where they remove material. Did Mopar ever have templates like for the cast iron heads for intake and exhaust manifolds? Pondering for my stroker build.
 
No experience here, but the extrude hone process intrigues me. I don't know how much material it does or can remove, but it flows under pressure like a fluid through the entire piece, so it only makes sense to me that the extrude hone process will flow through the piece similar to air/fuel thus following a somewhat "natural" path. Just my thoughts.
 
The extrude hone will only polish not really remove material. Radius the turns and the sharp edges under the carb. Beyond that your really better off with a performer RPM painted to match
 
650 bucks to extrude hone a cast iron intake. No way Jose....
 
I'm sure there's a purist somewhere that would consider it an option.
It's a very expensive way to gain very little power.

The basic internal "flow" design is an engineering compromise from the start due to cost, underhood packaging, strength/resistant to expansion cracking, etc. Maximum performance was not the real goal, thus the advent of aftermarket intakes and headers.

Can't polish a turd...
 
It really only helps on a dry intake(port injected) OEM stuff and exhaust manifolds. Our old wet intake usually do better with some roughness to keep the fuel suspended.
 
I think it's mostly only the guys running in the F.A.S.T. series that will spend the coin for this.
 
I think it's mostly only the guys running in the F.A.S.T. series that will spend the coin for this.

Even those guys are using Eddie manifolds and grinding off all the ID markers and painting them.
 
If extrude honing a cast iron intake was 300 instead of 650 I would maybe take a shot at it.
 
Beyond port/gasket matching and cleaning up the carb ports, you would probably be wasting your money at $650. You can buy a free flowing intake in you preference for less money that will work better. On the exhaust side, again port matching to insure a good fit. Keep in mind that with a stroker build you are increasing the displacement of the engine significantly. This in turn increases the exhaust flow and the heat generated by the increased flow. That is why a lot of folks wind up with cracks in their high performance exhaust manifolds without any modifications. Any metal you take off the exhaust manifolds leaves them weaker and more prone to cracking. If this a maximum output build, you should probably consider a set of headers.

Dave
 
I'm telling you the stock intake is not horrible. The Mopar performance M1 dual plane was a aluminum version of the stock 73 up spread bore intake. Round some corners, get rid of the sharp edges and port matched the intake and it will pull to 5500-6000 on a strong 440.
 
I'm telling you the stock intake is not horrible. The Mopar performance M1 dual plane was a aluminum version of the stock 73 up spread bore intake. Round some corners, get rid of the sharp edges and port matched the intake and it will pull to 5500-6000 on a strong 440.

I can agree with that....but then you still have the exhaust logs to deal with.
 
I can agree with that....but then you still have the exhaust logs to deal with.
I'm not dipping my toe in that hot water again. All these guys want to run 800 HP through exhaust manifold because they look correct, and headers are only for race cars, and I'm not going to rev my 800 hp engine over 4200 rpm, and so on. They have more excuses to run the manifolds than you can possibly argue against, nope I'm done.
 
They have more excuses to run the manifolds than you can possibly argue against, nope I'm done.

Don't you realize that 55+ years ago, Chrysler engineers KNEW that someday guys would be building 572-inch, 6000 rpm motors and they took that into consideration when they did their flow calcs? :poke:
 
Keep in mind that with a stroker build you are increasing the displacement of the engine significantly. This in turn increases the exhaust flow and the heat generated by the increased flow. That is why a lot of folks wind up with cracks in their high performance exhaust manifolds without any modifications. Any metal you take off the exhaust manifolds leaves them weaker and more prone to cracking. If this a maximum output build, you should probably consider a set of headers.

Thanks Dave so what are you saying, stock manifolds crack or modified crack or they both crack?
 
I'm telling you the stock intake is not horrible. The Mopar performance M1 dual plane was a aluminum version of the stock 73 up spread bore intake. Round some corners, get rid of the sharp edges and port matched the intake and it will pull to 5500-6000 on a strong 440.

Then maybe I will round a few corners and port match for a start. I can alway get a different manifold later if I want.
 
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