i have started to build my new engine and was looking at doing a p-port but didn't like the poor idle and no bottom end power i have put alot of thought in this and i am going to use my 6port ends with a p-port housing, but unlike most p-ports i am not going to block the old intake ports off. I am going to have the old ports as a primary and put the p-ports of a secondary so they don't have any flow until the rpm and/or throttle opens enough!


On that note has anyone heard of any engine being build remotely similar to what I'm doing????

 

Havent looked much into porting, but isnt your concept the same as a semi P-port?

 

First of all even if this was "your" great idea, how is what you described going to NOT have the "ill" effects of a full Pport'd engine? The Pport is still going to open and close at the same timing whether you have a smaller side port next to it or not. Overlap will STILL be occurring.....

Yes there is a way to accomplish what you are trying to do, but this is NOT how. Also you might want to do A LOT more home work if Y O U are going to be building this *revolutionary* wankle engine you speak of...... A LOT more.....

And p.s. this is known as a semi Pport (as stated above) and has been around since the dinosaurs .

-J

 

the idea is the same as a semi p-port yes but the difference is that i was thinking if you could use a smaller p-port only 1 or 1.5 inches and a sliding throttle plate right before the housing to eliminate all air/fuel flow at idle/low rpm/low load times it would get rid of most of the overlap but still provide more air as needed!


Its just an idea but i will be trying it out when i can get the pieces together, i figure any idea is worth trying.

 

The more experimenting the better. Check for a thread in the 20b section. GTO Rx7 has been in the development stages of this very same project for the past 3yrs on his 20b.

 

thank! i looked but didnt see it do you have a link?

 

If you would have searched the name I gave you, you would have found it. Here it is anyways.
https://www.rx7club.com/20b-forum-95/my-rx-7-done-cup-holders-3-rotor-semi-p-port-n-setup-stock-subframe-454580/

 

may have spelled it wrong when i searched, sorry

 

thanks for the link

 

It's been done before... Not a big deal. They've also had minimal overlap but IMO it's WAY TOO EXPENSIVE and honestly retarded. Go with a large streetport or go with a straight up P-Port and make the power. Regardless, I want to know what power you "WANT" to make... So lets hear it so we can all recommend a better setup.

 

I don't know why everyone says pports idle bad and have no low end. That is totally false!

 

well mono im really just building it to see what can be done! i just like to tinker alot, i know someone with a machine shop and i love to fabricate everything

 

i have had a few(2) p-port engines and both ran like crap under 4k and idled at 1900 but i guess it depends on the size and timing of the intake port because i have seen 1 or 2 that are good at low rpm(not the best) and don't idle as high

 

Can it idle at 700 rpm with the a/c on? Nope. Do they make good low end power when not under load? Nope. Don't think in terms of rpm. Think in terms of rpm AND load. That's what matters.

 

You can't eliminate overlap on a p-port at all. Not even on a semi p-port that closes off the runners completely. The reason is quite simple. When the apex seals cross the peripheral intake ports air can move from one side around the seal to the other.

 

im really just trying to minimalize the overlap effects not get rid of them as you said it will always be there

 

my revision of the idea is to have the p-port higher on the housing and divided by a bridge that would be timed to coincide with the timing of the side intake ports so it would be 96% overlap free the slide type throttle would still open as rpm/load/throttle position needed to get more air/fuel in to get more power but when closed almost no flow would happen between the two sides of the p-port


pic#1 the bridge

pic#2 the blue arrow is the bridge the red arrow is the slide throttle plate


keep in mind right now its only a brainstorm!

 

it may not work put its something new i am willing to try

 

Sooooo... Le tme get this right...

All you guys are saying it wont work?

WHat if the p-port is 100% closed till 6,000rpms+?????

Think of the p-port acting like a 6th port. ONly air comming in the engine is the stock primary ports. SHouldnt it idle really close to stock?

 

thats my idea but the small opening of the port even when closed will flow some air/fuel around the apex seal that is why i thought off the bridge to help stop that flow and flow still means some overlap

 

YOu cant clompletely close it?.. And let the engine run on the original ports... and then open the full P-port late in the rpms?

 

I dont know **** about this... BUt I guesstimating hehe. in theory

if you can keep the P-port 100% closed. NO air comming through at all.!

WHIle running of the stock ports... it should idle like stock... or close to it.

AS the rpms increase the p-port could slowly be opened...


does this make sence?

 

refer to pic one

the air goes around the apex

pic 2 and 3 the bridge greatly reduces the effect

red is the throttle plate the green is the air bypassing the apex

 

it can only be truly closed off if the throttle plate is even with the rotor housing and that is almost imposible

 

anyone got any ideas or suggestions to add??????