i just picked a spare head from the junkyard and will be prepping it to go on with the 4bbl. it will get new valves, seats and a port and polish.

does any body have any tips on porting this head? i have a comp cams 252S cam and clifford shorty headers. the carb will be a holley 390 cfm vac. sec. there is four speed bolted to the engine.

this car is mostly street driven and my focus is cleaning up the head for efficency not so much maximum flow. also if anyone has a recommendation for parts.

any help and previous exp. is greatly appreciated.

zedpapa

_________________
1970 dodge dart w/225 /6 bored .040" over, holley 390cfm w/vac. sec., compcams 252s, clifford shorty headers w/2.5" exhaust w/flowmaster, f-body 11" front discs, aluminum A-833OD, 8 1/4 w/3.21 SG
soon to have 5 gears!!!

As I tell everybody, do a search on here, there have been some good topics and replies on this subject.
It's called, "doing your homework"! I'm kinda in the process of doing the same with my head, and one of these years will put in the same cam of one of my own custom grinds from the Comp catalog. Good Luck

Sure!! Tip number 1......disassemble the head, take the casting to your local machine shop, have it hot-tanked and crack-checked. This way, if it's junk, you don't invest too much time and money into it, and you've also got a practice casting to learn on. If it's good, then it's nice and clean to work on.

Roger

Tip 2: Work slowly and check often. It's easier to take metal off than it is to put it back on.

http://www.sa-motorsports.com/diyport.shtm

_________________
"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Do all of the above. I would lay a intake gasket on both the head and intake manifold and match the ports. Then grind all the rough castings under the valve seat but don't get to carried away.

Dave M

i planned on port matching the intake and the exhaust to the head. i was also planning on doing some blending work on the transition from the valve seat to the port runnner, just smooth things out and then polish the exhaust until i can see myself in it.

zedpapa

_________________
1970 dodge dart w/225 /6 bored .040" over, holley 390cfm w/vac. sec., compcams 252s, clifford shorty headers w/2.5" exhaust w/flowmaster, f-body 11" front discs, aluminum A-833OD, 8 1/4 w/3.21 SG
soon to have 5 gears!!!

Plan on spending at least an hour per port and wear safety goggles.

That's not a wink, it's me trying to get the metal shaving out of my eye.

One of the heads I inspected had odd pieces sticking out the sides of the walls of several of the ports. It looked like those things that hang off the roof of a cave. I believe it was leftover from the origional casting process. I think removing those are good for a couple of CFM.

_________________
1980 Aspen 225 super six

I spent about 3 hours working over a used head. I'm half way done (6 ports 3 intake, 3 exhaust), a much better balance than last attempt when I put 4 hours into 2 ports. They were beautiful, but I was never gonna find time to finish them all that perfectly, but good experience.

This head needed new valve seals anyways, so I broke out my new die grinder and gave it a go. The die grinder was much easier and faster than the drill I was using in my previous attempts.

I put most of my attention at removing irregular material below the valve seats, smoothing the short side radius, and flattening/removing the valve boss.

Compared to those areas, port matching and polishing doesn't look all that important. There is a great deal of irregular material and it varies greatly from port to port on the examples that I've worked. Partially removing the valve boss is the hardest part because it's not easy to reach from either angle, but appears to be the biggest restriction in my minds eye.

I wish I had a flow bench so I could put some numbers to it, but I trust my judgement and the suggestions that I've collected from this site.

This will be my second (completed) ported head. The first was done by someone else and will be temporarily decommissioned in a few weeks (when I do the motor swap). I am eager to take it apart and have a more experienced look at what work has been done to it.

This is the most fun I can have until money allows for the purchase of some more interesting racing upgrades.

_________________
1980 Aspen 225 super six

what kind of cutter are you using? i have a small selection of carbide burrs and they seem to work well. however they are 6" long and can be difficult to control sometimes. i was thinking of getting some 3" or 4" long ones but no time and money prevents that.

zedpapa

_________________
1970 dodge dart w/225 /6 bored .040" over, holley 390cfm w/vac. sec., compcams 252s, clifford shorty headers w/2.5" exhaust w/flowmaster, f-body 11" front discs, aluminum A-833OD, 8 1/4 w/3.21 SG
soon to have 5 gears!!!

6" long is too long for the heavy tooling. They might be nice if you want to get really polished on the last 10%.

I'm going for a milder, "remove the big ugly stuff quick"



This is working pretty well. The longer stone is about an inch and a half. It started life closer to 2.5 inches (a little long), but was broken off and now ground down to a nice rounded end.(from working bosses off with the tip) It's working pretty good, but getting a little hard to reach the boss from the manifold side.

The other little cone shaped stone is good for along side the flattened boss and blending it into the bowl area.

My biggest headache is getting enough light to actually see what I'm doing without having the light right in my way.

I'm don't profess to be an expert and I don't have any flow numbers to back up my methods, but for raw material removal, this is working well.

_________________
1980 Aspen 225 super six