I want to bridgeport some secondary plates that were allready streetported for early opening and I do not want to compromise the oring. This means this new hole could not be more than 4 (maybe 4.5) mm wide.
I want to know is it worth it?
Attached is a picture of the port.

 

I'm watching you Mo

 

Here are two picks comparing a stock port and the street port along with a 1/4 " bur.

 

In my opinion you would be better off getting a stock plate to bridge. By the looks of the picture, the streetport is pretty large. The size of bridgeport you would be able to put in would be small, plus the actual bridge would probably need to be pretty narrow, which means it will crack or deteriorate sooner.

I think you should get stock ported plates, put a good sized bridgeport on them, but try to keep the bridge a decent size so it is strong enough not to crack and will allow your engine to last longer.

 

I concur with Bridgeported: best to start with stock plates.

Get a Racing Beat template and lay it over the plates. You'll be able to see what can go, and what needs to stay. Templates are cheap. Plates are not so cheap.

bridge porting pics here . When you hit the water jacket, that's when you stop

 

Those plates are a bit far gone for a reliable bridge to be added. Maybe you should look to a partial PP if you want to keep those end plates ?

 

I guess I could not get away with a 4mm hole.
qwck10th, Your ports look close to mine. You original port was brought towards the oring. You just went a little too high on the port to create the bridge.Thanks for showing. What did you ever end up doing with that that plate?
RICE RACING, would partial PP would need a special intake manifold? What kind of work to the rotor housings would be needed? The plates I have are from a series 5 plates.

Bridgeported, your port pictures are sweet. I did not want to go spend money for some plates. The stock plate was borrowed for the picture.

Any sugestions on going into the the oring?
There is a guy an hour from me who says he has been running an oring bridgeport for three years without a leaking problem. Plan to go pay him a visit this week.
I am running a centrifugal supercharger. It comes on strong above 5500rpm with the curent gearing and i will not run it past 8500 because the impeller may come part.

 

originally posted by mospeed
Hey thanks. The first port picture in my sig is of Soul Assassin's engine if I remember correctly. The second picture I grabbed from www.fc3s-pro.com (awesome site!). The last pic is from a Sevenstock 4 collection.

 

It can range from mild to wild (manifold) The ones I have done and seen you simply need to get a machine shop to weld up some extra runners to intercept the secondary runners on the lower intake manifold do a little machining and there is your manifold.

For the rotor housings you need to get some devcon or other good aluminium epoxy bore a hole throught the water jacket hole through the rotor housing and get "Creative with the die grinder"

I can send you some pics of the housings after being modified, one forum member (sorry name escapes me now) posted some pics of his manifold he modified to do the job after deciding to go the partial PP route......from memory he liked it.

 

I was looking at my series4 lower intake manifold and noticed that the two round spots to mate flat with each rotor housing no larger than and inch. Sounds interesting. I would not have to cut an oring but I will need to spend some money on the manifold. I allready have a lb of devcon for aluminun(Part#10610)..
Pete, I would apreciate these pictures.

 

Those ports follow the Racing Beat templates. The oring is not compromised - though the rotor housing has a matching notch. Turns out porting into the water jacket is ok, and pretty common. There is barely any metal there. I was just blending the port into the bridge - nothing wild. With some good advice from Judge Ito, and JB Weld... that motor is now sitting on a 5 gallon bucket in the kitchen floor - half stacked - finish it this weekend

Cheers.
s

 

Glad to be of help to another rotary engine brother like you..

 

Hi Moe. I would agree with most of the bunch. The streetport is ported a little to large. Going bridgeported would not be the more reliable way to port (does) plates. Now a nice semi P-Port would not be a bad Idea. Jay Tech that use to sell intake manifolds is back in business selling his manifolds. I know we makes turbo II and FD manifolds with the semi p-port runners already built in. I have his new phone # in my shop and Ill post it if your intrested...

 

I'm going to suggest something here. For the serious bridgeported engines. I would recommend, anybody that is going to really try and blend a nice flow into the ports, before you even start porting, take your time and sandblast or clean the back of the port(the side of the port that is on the water jacket side) Carb cleaner works fine too. I mean clean it really good. Then just blend some JB Weld together and lay the weld across the back of the ports, Don't be shy when doing this use a decent amount of epoxy. This way you could port with all the confidence in the world and not worry about the water jacket so much. After that start your porting and flow into your bridgeport opening.

By the way I personally use a nice fat straw and run the epoxy well into the straw, then position the straw in the strategic points and a little air pressure. After is done, it looks like that epoxy was born there..

 

WOW. Between Thanksgiving here in the US, PC issues plus this Forum having issues, I am just getting back.
Judge Ito, Thanks for the info.. I like the straw trick. I went to look for John (alias Bridge) up in Bardonia NY. He is making me a believer in going into the oring with the bridge. He personally does not like the height of my original ports(the lateness of their closing). He says Oring bridgeports can stay together for years. He gave me some tips with the epoxy and also gave me some ingredients (PYRO putty) to help get the job done. Just got to figure out how to build a port to build the best power between 4700 - 8300 rpm. He also hooked me up with a scattershield a month ago for my turboII bell housing. It came from Roberto out of Philly(good Machinist).
qwck10th, I knew you were going to use them there plates. Happy motoring.