porting heads

[Thenwhat85]

Okay mopar owners. I need some guidance, I purchased some promaxx 440 heads. Am going to port match the intake to my max wedge indy intake. And clean up the casting. My question is about the exhaust. I was reading in a mopar book that you don't want to port match the floor of the exhaust(okay to do the sides and top). This was on stock heads though. So is it safe to port match the exhaust on these aftermarket heads or stick with just doing the top and sides? Thanks any advise is appreciated. Pictures attached

 

[mguner]

Be very careful on the short side radius! It must have a nice rounded curve from the seat blending into the bottom of the port. Just some cleanup on the bowls and you should be rocking. Taking material from the bottom is a no-no unless it is just flashing or core error.

 

[moper]

I used to gasket match the top and sides - I no longer do that. Shape the bowl and smooth the transitions but I do not enlarge the port exit in any way anymore. Your heads are already realy good, and if you think the shape of that port really matters, you're overlooking the basic physics of a cylinder full of very high pressure gases that suddenly opens an escape route. It's much more important that the port be an extension of the header primary and not a larger volume leading to it.

 

[toolmanmike]

They look like real nice heads. I wouldn't mess with them too much. I would leave that to a professional.

 

[zac_F71]

I agree leave head porting to a pro..

 

[RustyRatRod]

Call ProMax and see what they say. Without knowing how the originals are cast, you are kinda in the dark.

 

[Thenwhat85]

I don't want to full out port them. Just clean any casting and end the turns a little better. I know not to mess with the floor with out a flow bench and practice heads. I wanted to know about the exhaust port. I the picture there's those shells in the corners of the port. Should I smooth those into a nice transition(remove the selfs) thanks for the help so far.

 

[moper]

If it were me, I would just blend the transitions on the sides and roof from the opening back to the throat cut in the bowl. Don't enlarge anything, don't alter the general shape of the port, don't mess with the guide, and don't touch the short turn. This can all be done with a sand roll and should take about 3 minutes per port.

 

[Breadburner]

You will likely do more harm than good....

 

[rumblefish360]

I doubt that. Over zealous work will though. At this current point in time, due to the lack of info, less is better and a blend from front to rear isn't a bad thing on the roof and sides. The 2 important areas.

 

[Thenwhat85]

Thanks guys I'll post up when I get my gaskets from hughes. I don't want to enlarge anything(well except the intake to match my max wedge intake) I just wanted to know if to remove those shells in the exhaust port and if you gasket match the exhaust floor. You have answered my questions. Supposedly promaxx is working on a cnc ported head. But they don't know when it's going to be done and i need to get this race car done this year.

 

[Thenwhat85]

Thanks guys I'll post up when I get my gaskets from hughes. I don't want to enlarge anything(well except the intake to match my max wedge intake) I just wanted to know if to remove those shells in the exhaust port and if you gasket match the exhaust floor. You have answered my questions. Supposedly promaxx is working on a cnc ported head. But they don't know when it's going to be done and i need to get this race car done this year.

 

[Marcohotrod]

what size header? and for example a 2" header is 2" outside diameter. the exhaust port does not get matched to the gasket, it gets matched to the header inside size, or slightly smaller than the header inside size

 

[Thenwhat85]

Yeah the plan it 2 in header. I know they go by od. Only thing is I'm going fender exit and my primary's will be about 26 inches long withe about 6 inch length collector. I will wait to get my header flange before I go off the gaskets

 

[bOb shingler]

yes take that shelf off all 4 corners of the exhaust port and that should do it. on. with the intakes, gasket match and blend in for a nice smooth transition to the stock walls as for in as you can reach.