79+80_rx-7

I mean a full bridgey!!!


With stock apex seals(is that ok?)


Rb exhaust, and holley carb, ontop of a RB intake...


This will be street driven, at least 3 times a week, about 10 miles....


Thanx! Laterz, Andrew

DriveFast7

iTrader: (1)

if built right, not revved over 8500rpm (and a full J-bridge's powerband is 7400-9400rpms) and you don't bake the motor it'll last a long time.

of course you'll need to rev that motor up to make power. . . . .

S2-13BT

It'll be fine for a long time as long as it's built right to begin with. A bridgy doesn't compromise the water jacket, which is where you start to get into problems.

Also, as long as it's built well, revving it up shouldn't be a problem, and with a bridgy that's precisely what you need to do to make power.

Good luck with it.

peejay

You can't do a J-bridge with stock seals. If you use the stock seals, you cannot relieve the rotor housing where the apex seal corner piece is or it will fall out.

79+80_rx-7

okay... Well, if I get a gasket set, carbon apex seals, and reuse old rotor seals, will it work???


I am just wondering, trying to save deniro...


And if the motor needs a E-shaft, will I have to get it all balanced?



Tell me the best route.. PLEASE.... might be getting a full bridgey.. and I am VERY ANXIOUS!!!

Zulu

The best/most reliable way is usually going to be the most expensive way. Don't skimp out, replace everything that looks in anyway worn.


On another note, peripheral port, you know you want to.
http://sk1llz.net/4rotor-2.mp3

79+80_rx-7

i guess I will just get the car, carbon seals, hardened stationarygears, carbon springs, gasket set, and I hope I will be set...


Well... THANX, LATERZ< Andrew


Anything else I should know?


will someone PLEASE look at the port, and tell me if it is correct...

S2-13BT

Looks okay to me. Did you use a template?

Just check that the seals don't fall out of the rotors. I'm sure port timing has something to do with it, but I'm absolutely no help there.

BadAssRX-7

didnt grind on the housing....... or so it looks so you arnt getting th full pot. of that port

79+80_rx-7

well after badass's advice, I have decided to buy the car that this comes with, and go to a street port...


I will find another set of plates, and street port them, and leave the center plate bridged...


Thanx, LAterz, Ansrew

WackyRotary

Who did your exhuast ports? The one in the pic looks very very large. Is that a mazdatrix mod'd one?

BTW, I see by that endplate its a '83-85 engine bridged. Hope you are converting to use a front mount oil cooler as I did. I drove mine with the water/oil cooler in december in MN, so temp was fairly cool and could keep up ~ok. But don't do that if you plan on driving it hard in 50F+ weather.

As for the ones in your pics look very simialer to my porting I did. I would suspect your power will fall off at 8500rpm. I never rev mine past 9000rpm, unless I were to miss a shift, there isn't any power up there anyway, just drops off, and carb jetting is not revealing any more gains up there for me. It peaks at ~8000-8200rpm. Depending on the exhuast, it will build more power. I gained much power after going to long tube equal length headers. But also lost 80% of the power below 4000rpm at the same time. Anyway they collect at ~120inches. That was the fastest gain in power WITHOUT DOUBT! Without a good exhuast, the bridgeport wasn't very quick.

Heres my little chat on that:Bridgeport Link

Some of that info is not completey up to date though. I will add more pics when I scan them.

REVHED

Is it just me or does it look like the inner edge of the main port has been ground out?

peejay

Andrew showed me thos pix over an AIM conversation. It looks that way to me too. If the inner edge WAS ground out, the outer oil seal will overlap the edge and the engine will burn oil. Dunno how much or how fast, but it wouldn't be any good.

I also don't like the way the closing edge of the main port is shaped... it has a sharp point where the closing edge and inner edge meet, I don't like to see that.

REVHED

Yep, after looking at those pics again it seems that the inner edge has been ground out quite a lot. It has a big kink in middle as opposed to the nice smooth curve that it should be. I'd stay well away from that engine...

S2-13BT

Wow, ya learn something new everyday.

So, the idea would be to keep everything nice and smooth, with generous curves (as much as possible)?

Also, does it look to be about the right size? I mean, not too far up or down. What kind of effect would going to far up or down have on the engine?

Thanks, this is quite interesting. As you can see I'm still new to this porting stuff, but would love to learn as much as possible.

peejay

My personal pet theory is to optimize the shape for the point where rotor speed is highest.

http://personal.riverusers.com/~yawpower/rotcyc.gif

What this entails basically is trying to shape the port to bias flow to where the number 3 is. That's basically where the center of the chamber is at the point of fastest chamber expansion (accord to Paul Yaw's site, and I trust him ) I did this with various methods involving gut instinct, as well as water and air streams. Not the most scientific way but a hell of a lot better than "let's hog it out real big-like".

My intake ports looked kinda like funky kidney beans. Definitely non-conventional to what you normally see.

MIKE-P-28

iTrader: (1)

Anything ground towards the E shaft is a trashed piece...

WackyRotary

I didn't notice that. I figured he cut outward towards the bridge. Also, even though my pics don't show transision very much, i did infact spend as much time cutting as I did making the edges smooth.