How to port factory iron heads?

[Benjamin Nelson]

Hey everyone, I am rebuilding the 440 that is going into my challenger and am wanting to port the heads a bit. It is a race car and I am shooting for 600 horsepower or around there. I have factory 915 heads from 1967 and am wondering how I can go about porting them and doing some bowl work. Any help is appreciated.

Thanks

 

[Juan Veldez]

First thing is to select the intake and exhaust gaskets you plan to use. Use them as a template on the faces of the intake and heads. Use a sharpie or metal scribe around the gasket openings. This shows how much needs to be ground away to align the ports. It is easy cheap horsepower without major work, but remember that your trying to create a smooth even transition without creating larger versus smaller port areas along the way. Intake ports should be a little rough, exhaust ports whould be shiny and smooth. Anything beyond that, you should send them to an expert as they really start to change the angles of the flow, are very exact on port sizing, etc. If money is available, I'd go with aluminum heads as all that work just mentioned is super easy, and they start out making more HP than factory.

 

[gtxno1]

Drop them off at a speed shop that knows mopar that old gasket trick will not get you much a real professional will get them to flow properly but the priced paid will be alot go aluminum

 

[moparleo]

Completely agree with gtxno1, Like anything else, to be competent takes years of practice and the proper tools.
You won't know what you have without a flow bench. Port matching and bowl work won't get you there.
Pay someone else for their experience.
Most engine builders have someone who specializes in head work to do it for them.

 

[moparlifer]

Back in the day (mid 80s to early '90s) Direct - connection sold a clear plastic porting template for about $15 that you could cut out and stick into the valve-stem hole at every 15 or 22.5 degrees and grind straight down from the bottom margin of the valve seat to blend the bowl. you just grind with stones and porting cones on a drill or Dremel tool.
I spent a god 40 hours, if not more, getting mine ported and polished to match the template. Most porters also recommend grinding down the underside of the valve itself to take off any excess margin under the last angle of the valve job to the beginning of the transition from seat to stem.
The template was developed and flow-tested by Ma Mopar engineers or partners to get the max flow out of the 906 and DC Stage 4 and maybe stage 5 heads if I recall correctly. Should work on the 915 heads, but not sure. -I think I ran across them a week or so ago sorting out all my ancient stuff. PM me if you want me to provide further detail.
FYI-I bought a set of hogged out 915 heads before I got the 906s and templates and it ran way worse than stock so don't gasket match and call it good. My 2c

 

[gtxno1]

At best you can do the bowls only porting is left to someone that can flow

 

[Chryco Psycho]

I spent years doing this & figuring it out , If I had not lost 14 computers in the last 2 years I would have good pictures but they are gone ..
SO most people believe air flows straight so they make a large straight port , But air acts just like a fluid , ever watch water flow down a drain ?? Swirl is key , you want to turn the air into the port & through it , you need to make the valve guides just like a wing with a long & short side , curved on the leading edge & knife edged at the rear , you also want the air to flow into the rear of the valve at a 30* angle or better not slam straight into the rear of the valve . I have proven all of this on flow benches BTW .

 

[Mopar Nut]

Go with Trick Flow 270 heads or maybe 240. Less headache, with a better flowing head. Lighter for a race car anyway. I thought about having my iron heads rebuilt, ported and hardened seats installed too. It was going to cost close to new Aluminium heads.

 

[Daves69]

Back in the day (mid 80s to early '90s) Direct - connection sold a clear plastic porting template for about $15 that you could cut out and stick into the valve-stem hole at every 15 or 22.5 degrees and grind straight down from the bottom margin of the valve seat to blend the bowl.

Just for reference on the template cutouts.............

 

[Benjamin Nelson]

Hey thanks everyone. Yes moparlifer I am interested in the templates, I will send you a message.