Found this on a site was just wondering if any ones used it or seen any thing like it hmm

Looks like one of several variants of porting that get around rulebook bans on bridgeporting, by having only one port but still going into that area.

how does that effect sealing / lifespan though?

that looks like a seal grater to me

Ports like that is why the SCCA Porting rule is written the way it is

Lifespan doesn't matter as long as it makes more power than a side port, while still meeting the letter of poorly-written rules banning bridge ports.



Funny how rules intended to keep costs down often end up making things a lot more expensive, eh?

Not as bad as a bridge port. Everything is supported all of the time. Very good idea, but hard to do well.

Notice a mill was used on this one.





Lynn E. Hanover

Correct have a read through this and it mite explain it a lil better

http://ausrotary.dntinternet.com/forums/vi...&highlight=port

Sorry bout the doble post but i thought i'd put up the main points in how this port came about

Posted: 1010111105050505 Post subject:



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I can tell you exactly how this port arrived.



In the Late '70's there was a Aussie 3 litre production racing class. Primarily Capri & RX-3's. The Mastertons, Bo Seton (Yep Glenn's old man) and Peter Williamson in a very hot twin cam Celica were all part of this.



I worked for Barry Jones in those days and he was kicking Capri ass running bridgeport engines. Anyway the powers that be - the ARDC (and CAMS) decided that the bridgeport was equivalent to opening up a new port in the motor and banned it (read he was too fast).



Barry developed the new port to give him more port opening without creating a "new port". He went to his mate Chris Dowd (in Woolongong - ex Honda Australia race mechanic) and they cooked up this new port.



You should have seen the faces on the race scruitineers when he proceeded to kick some more Capri Ass and they proceeded to pull the motor down. Yep 100% in the rules as the tooth was just an extension of the existing port.



We used to call it a "tooth port" for obvious reasons. It didn't (if I recall) eat corner seals but there was limit to how wide you could make the "slots".











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The way the rules were written in the Group C days were not very kind to the Rotary engines as far as porting modifications go.



The rules stipulated you could change the shape of the port but you could not have more ports. Bridge porting is by definition adding four more ports to the engine so Barry figured that if you used a finger style port you still only have a single port, but with similar characteristics to a bridge port.



Ultimately it is not quite as durable but with a race engine which you check every few races it's not an issue.



Once the rules were relaxed to allow bridge porting and then peripheral porting this form of porting was no longer needed.



It goes to show though that a clever person will always find a way to get around certain rules

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