Bridgeport Much?
 

So I've been looking around for Bridgeport templates, which can be found here: http://www.rotaryshack.com/portingtemplates.html

My question is what is the difference between standard bridgeport, j-bridgeport
and D-port bridgeport?

J bridge goes into the inside water jacket, freaking huge

not sure what a d port is

G'day,
Here in aus our J-port is just like a bridge port. Where the 'eyebrow' gets cutout above the standard port(to make a bridge) this 'eyebrow' shape gets lengthened out further to make it almost look like a "J"(funny enough)... I never heard of a "D" BP...?

As mentioned above the J-port will interfere with you water seals which will sacrifice lifespan.. Bridge is probably the biggest port you can do before engine longetivity and low-rpm drivability will be an issue.

Depends what your using ya car for, Street/Race/Drag/Drift etc. And then go from there. Have a good one.

i might be mistaken, but i think this is the general idea behind the D-port.

https://www.rx7club.com/showpost.php...2&postcount=13

autoX

"AutoX". Is that some sort of 'motorkhana' or something like that??

Pretty much if you are gona use it everyday to get around i would suggest go no bigger than a standard bridgeport, but if its gona be used for events(one a week or a few times a month) then what ever port workx the best for your set-up, go for it.

The idea being to save money.....You dont want a J-port daily that you might have to rebuild every few years so build your engine depending on what you plan to do with the car.

Holy SHIT!!! Thats massive!!! Almost like a monster-port.
Good to know tho, so thanx for that..

well, hold your horses for now and wait until someone more experienced with different bridgeys can confirm it. some of the ports have more than one name (whether it's for real or simply because misinformation got passed on) and i think i saw something similar to this shown as a D-port in the past. however, i'm not 100% positive. :) i guess the simplest solution would be to ask Robert, himself. i think i will when i get a minute to send a PM.

Here in aus we keep our porting templates pretty simple. With all the diffrent types only really varing depending on the workshop. Over there you guys have sooo many diffrent names an types/variations to 'em that it's a little confusing...
Over here we don't have 'streetports' or 'D-bridbeports'... Wouldn't mind learning about it tho...

well, i think our streetport is essentially what you guys call the extended port, and of course there are varying sizes of them.

the bridges are where things seem to get confusing very quickly. i plan to familiarize myself with the different bridges though. that's one of my goals for 2008. :)

Ok, for auto-X you need to think about more than just the bridgeport. I personally like the BP, but in this situation you mightfind you are biting off more than you can chew.

The port timing for a BP induces a lot of port overlap which will cause a dirtier intake charge and make the engine run like absolute ass ~ 750 RPM, so you are gonna have to increase the idle to allow it to run. It is also going to lope a little but if you don't care about sounding like a badass when you roll up anywhere then it shouldn't be a problem.

Here is the problem,the BP allows the engine to breathe a LOT more air, thus, you are going to have some boost issues if you pick to small of a turbo. You motor will literally eat more boost than a smaller turbo can push at it, the obvious answer to this is to get a bigger turbo, but for auto-x, this will cause a few issues.

1) unless you drop some money on a very nice turbo that spools well, you are going to have lag, which means when you are coming out of a corner in the lower RPM's you are going to have to wait for power which is going to piss you off in an unbelievable manner.

2) if you do go ahead and spend money on a good larger turbo that spools well and can keep up with the motor's air demand, then you are going to have (if the car is tuned well) a very very very steep powerband that comes on like a bat out of hell which means you are really going to have to re-learn throttle modulation in a corner. (trust me though, it is a blast once you get everything down.)

3) power, with a standard bridgeport and a good turbo, say, a 40R (bout as small as I would go with a BP) your potential power output is going to be retarded, go buy good tires now and keep spares in stock.

You basically have to match turbo, port, and fuel demands to build a good auto-x car. It might be a bitch to race at first, but once you get the hang of it you are going to be having fun like no other.

As far as bridges go, there is a full bridge and a half bridge. The half bridge is a BP only on the secondary intake ports (or is it primary, sorry I am tired) which is supposedly more streetable. It's supposed to be a compromise between a street port and a bridge port. Then there is the full bridge port (my personal favorite) and there is even a finger port but those are rare and only used in situations where a Bridge port is not allowed by the rules. Don't even worry about the finger port though as they are INCREDIBLY rare and I don't think I have ever seen a thread referring to one on this entire board. And the D bridge is regoddamndiculous. It is basically a Peripheral port and the motor is only expected to last once race. IMHO, if you want a streetable car that can drag race and auto-x and you have big balls, go with the bridge. If noise or idle / light throttle response is extremely important to you, stay the hell away from it.

If you want to see a site with good info on ports and what they are used for, check out www.rotaryengineillustrated.com. They have pics and explanations for each and basicinfo on expected powerband and usages.

Hope that helps you out some.

-Maniac

^^^ Good info, san q.