Ive got an Idea



couldnt u welt two peices of metal to support the seal and make them flush with the housing wall, it would hurt flow but you could go alot wider and therefor increase the flow overall?

That's a gorgeous port!

i likey! be neat to see a pic of that next to a stocker

Very well said........I totally agree.









I don't think it hurts the midrange at all. My ports looked similar to the one Ted is showing here and that is using a TDO6H-20G #17 exhaust side. You can see the Dyno in this post.



Exhaust Ports



My midrange was excellent. The Shops here in Japan definatley use larger exhaust ports than people in America.......you would be suprised how big they go. They do however warn about going to wide.

Exhaust porting is very very sensative. I did the exact same exhaust port on 2 engines, except it was located slightly lower in one of the engines. The midrange and low end on the one with the lower exhaust port was much stronger, with no apparent loss in the top end. I was amazed at just how much of a difference it made in drivability.

thats just from less overlap, some is good but you can have too much (iHmo)

Thats an awesome looking port,.. I just measured with a caliper and a 2.25 inch wide exhaust port leaves almost exactly 1/2 inch on each side, so it looks like the i heard bout right...Anyone with a degree wheel know how many degrees per milimeter up or down it is?

Well, Ill have to disagree on the blanket statement that some is always good. For instance, F1 engines run zero overlap, and the redlines are creeping past 19K rpm. Many new production cars, most notably the newer hondas, including the S2000, run zero overlap, as well as the Renesis engine. Yes, I know those two examples are polar opposites, but its to make a point. In both cases, the advantages of overlap did not outweigh the disadvantages.



Now, take old school pushrod V8's. They need a lot of overlap to make power at higher rpms. But they lose a lot of low end from the overlap, and drivability as well.



I pretty much only port down. I take the top edge up to the top of the stock bevel, and then bevel that. I get enough extra overlap from the early open SP. Then I just port down and out.

Yeah, that's my Stage I exhaust port. https://www.nopistons.com/forums/pub...IR#>/smile.png

It widens significantly, but I don't drop the port too much - maybe 1/4" or so.



These are the Stage II exhaust ports - dropped almost 3/4". https://www.nopistons.com/forums/pub...#>/biggrin.png



http://fc3spro.com/TECH/MODS/ENGINE/...ING/s2ex01.jpg



http://fc3spro.com/TECH/MODS/ENGINE/...ING/s2ex03.jpg



Comparison to stock port https://www.nopistons.com/forums/pub...IR#>/smile.png





-Ted

Thats huge,.. I feel insipered....