Thus the reasons for my questions...

When you've gained big flow #'s while maintaining or even improving velocity, then you've done something...[img]i/expressions/face-icon-small-smile.gif[/img]

 

I had gotten afriend to pick me up one of TVI s head down in Oregon in sept. All I can say Holy Crap,What a difference in revs and power.Nice investment
If you dive in there and do you your own work, make sure you dont damage anything and good luck

 

i've had head work done on both of my ds's the stage two is port matched and cleaned up what little it could, wouldn't said it made a hugh difference, better but not hugh. went to the race head and that is where the zoom was very big it was a pami head but due to some water leakage gasser hooked me up with one of his and i'd say it works better, but at those power levels most people smile and can't tell the real difference. I know the price of the race heads concern people but the difference is hugh.

 

222 is right on the money! Large flow bench numbers dont allways mean large HP gains. If you are running stock valve seats, just clean it up so its smooth with no rapid transitions. Dont hog it out, or take much off anywhere. I believe best finish in the intake runners is beed or sand blasted. The slight texture helps atomize fuel better.

I also believe the exhaust runners should be more like a polished finish, so carbon cant cling to the runners.? Corect me here anyone?

As far as flow bench readings, there only true in the static world, as in, not changing. In reality, the intake valve opens and closes causing pulsations right at the valve bowl near the seat. The air flows like a fluid somewhat, but when the valve closes, the air somewhat compresses, or packs up near the valve, the air leaving the carb should see less of a pulsation as its velocity continues to flow and pack up towards the valve. The valve then opens and the velocity should have not stoped and the slight presure from the packing affect sort of blows into the head under slight presure. Free supercharged affect.! The design of the intake runner affects how much this packing affect works or hurts your dynamic flow. (Horse power)

I have cut open many dodge turbo 2.2L heads and practiced on them in my pursuit of my 21 PSI turbo 4 cylinder Omni GLH project. I worked wiith a local race shop and had oversized valves/seats and complete chamber and runner porting done. After wich i somewhat coppied on lesser heads with good results for other vehicles.

I do know that the intake runner should increase in cross section area just prior to the valve seat. This area i believe is called the bowl. The size of this bowl as compared to the rest of the runner, as well as how they blend into each other, and into the seat, affect how well it packs without loosing velicity.

What does this mean for the do it your selfer like my self? Dont go nuts untill you have looked at quite a few different good PROVEN porting jobs on various heads. Practice on a bum/junk head, even if its not a DS head. Jus to learn how to use the tools, and what kind if finish you get.

I plan on doing my DS, but will most likely just blend the manifolds to the head and take out the rough spots.

In my opinion, the best gains from a stock set of valves and seats, will come from just cleaning it up, or matching the ports and lightly smoothing then bead blasting. BUT! If bead blasted, Make sure you presure wash the crap out of it.!!!!! Those beads can stick in the little spots and kill your motor!!!

Keep it simple, dont remove much, you will be satisfied. If not, pay for larger valves and seats and get it done by a pro. Biggest ruel for beginners, dont change the shape of the runner, just smooth it a bit to blend it to the intake and header. Not looking for large changes here. Stick to this and you should be ok..

 

Very, very well said berksglh and 222.