It made perfect sense to me.

 

Tooo Thhhhheeeee Ttttoooooooooooop!

 

Is this seriously all the information that this forum has on bridgeport 13b's?

 

how much r gene bergs 56 ida running

 

your stage 3 oil mods are here:

http://pineappleracing.com/PricelistSvcs.html

it'll also need hardened stationary gears, highrpm clearancing of rotors and e-shaft, balancing, carbon seals, etc..

more good info here:

http://mazdatrix.com/r-20.htm just replace the word peripheral with bridge

 

awesome!

 

I have some info on how my j-bridge was built at home, i'll see if I can dig it up and hopefully copy - paste. one thing that no one wants to hear is that new housings and rotors have zero wear and therefore better compression, make more power. guess who got a whole new block and rotors.

mazdacomp is your new engine price friend

 

Looked at my motor quote, only thing to add to the above:

Don't need set screws in the rotor bearings, if a bearing
starts to spin, the set screw rolls and locks up the
engine, maybe crashing the car. Rotors are cheap in
comparison. Don't need snap ringed rotor gears, people have had trouble with the snap ring exploding.

Go for it.

 

Have you dyno'd your j bridge? And I love the pics of your car on the Hywy. It looks just awesome!

 

I see the problems other than the rotor housings haha. From what I understand (and have been vaguely told) 12A irons dont fit to 13B housings due to the locations of the seals on both engines being different in design. They can fit, they just require ALOT of modification to the irons.

HOWEVER:

If that is incorrect information, and 12A Irons can be used in the build of a 13B motor, I would highly recommend the usage of the 12a centerplate instead of an SE centerplate. If anyone has ever seen an SE centerplate next to a 12A centerplate - theres no question port-wise of which one you would pick to work with.


I recommend EFI, even though Im a carby guy.

Just my 2 cents.

 

Were you planning on building this engine, or having someone build it for you? Someone here posted on some parts they were using in their 13b rebuild and they were planning on using the Renesis bearings but were only able to get the front beaing (used a 3 window race bearing for the rear). If you are keeping it NA it seems like rx-8 bearings and rotors are a good choice. If I had an endless budget or NA 2 rotor I would go with half-bridge, clearanced where needed, 4 port, race and hardend bearings and gears, S5 rotors and housings, OEM 2mm apex seals, replace oil jets in e-shaft (weber jet mod), baffled oil pan (Moroso makes one I believe), high volume oil pump and higher pressure oil regulator. For fuel I would inject it using Megasquirt (injection could be made very simple if you used the center plate from 13b, Turbo II maybe?). I believe if you went with that method for injection you could use the rest of the stock S5 intake components (intake, throttle body, sensors, etc.). For exhaust I would go with the racingbeat's streetport exhaust system

If I am wrong with any of those ideas or suggestions please do not hesitate to correct me. After all, i do not want to be spreading false information.

 

yes, 12a j bridge put 205hp to the ground @8800rpms, 30*L timing memory serving me. 42mm chokes in dellorto. good exhaust system too.

 

you heard wrong. 12a locate the water seal in the rotor housing just as the 74-85 13b did. Then in 86 Mazda changed the location of the water seal to the side housings. So therefore 86 and later 13b's and all 12'a will not be compatable w/o lots of work....

 

wow only 42mm chokes! and a side draft. With a 51 IDA and some 44mm chokes you might be able to hit 220 whp, but those IDA's are sodamned expensive! Good news though Weber is finally of of their 3 year strike and production has begun again so we shouldstart to see the prices of webers fall again...

 

check e-bay. My bro got lucky and picked up 2 48 IDA's for $600 as in "Buy it Now". Now we got 4 48 IDA's in our junk collection, err display case.

 

42 give better torque and wider powerband than 44. It's not only about peak HP. I was told to only use 44 on a horsepower track like willow springs, 2.5miles 9 turns. 2mm more choke would not add 15hp. the IDA would add mabye 5 more hp from everyone i have talked to with experience *and* dynotime with both setups. Not worth the $$$. BUT it will narrow the powerband a hair and push peak HP up another 200-300 rpms which means the motor gets that much more wear. But thanks for the input. Brad.

 

LOL good response, but my key word was might... I was just shocked because people were telling me that 40mm chokes on a medium to small bridge wouldn't get me any where near 200 to the wheels. I like my carb and would hate it to be a waste, so you my friend, give me some hope.

 

remember, i have a 12a motor i'm talkin about. B motors get more choke. who will port your motor? a good 13b jbridge will make 280-300 at the fly.

 

i will be doing the porting...

 

So in your oppinion what could I expect if I ran 40mm chokes in a 45 dcoe with a medium bridge? I was told from other sources that I could just run the carb choke less and it would be okay. I'm pretty good with the dremmell also so I was thinking or porting out my chokes to 42mm just so there is some choke. The biggest chokes available for the 45 are 40mm and I have a few extra chokes around incase I mess things up.

 

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