Ive got a 1990 n/a. the motor has been rebuilt by the last owner and now has about 25, 000kms on it. I am re vampingthe entire car and pulling the engine in order to re paint the engine bay. I am thinking about getting a port job done to the motor while it is out, keep in mind that the motor already has a very very mild street port. I hear that a bridge port will be failry unstable but i would like a better idea of how unstable. For example, what is an average # of kms clocked on a bported motor? or will i get better gains from a new intake and exhaust setup?

 

I've never seen a bridgeport get more than 10K Miles or what 16K Km....

Don't Do it!!!

 

i wouldn't pull the motor apart until you have to. no sense in paying for rebuild for a miniscule amount of power.

i supposedly got a stage 2 streetport on my Atkins motor, but hardly noticed any difference with my stock intake and exhaust on. needless to say, i was pissed and expected more from a large streetport.

 

understandable, i mean after all the motor can only breathe as good as its smallest piece, what kind of horsepower returns would i get on an aftermarket or modifided i/m setup with a head pipe (since ive already got 2 3/4" cat backs)

but either way does anyone know what kind of power you could muster from a bridge port, just for curiosity sake

 

Thats not entirely true. They do need partial rebuilds every 10-15k miles, or so, but its to replace the seals. The way bridge ports are made, they end up compromising the integrity of the water and maybe oil seals, so they have to be replaced about that often. Its not a full rebuild. If you have another car to drive while your working on the 7, and you are comfortable working on the engine, then you might be ok. If you dont have a daily driver, you prob shouldnt even get a bridge port anyway. They have very rough idles and even worse gas milage than normal rotaries. Search around and you should be able to find more comprohensive descriptions, as well as links.

 

Also, what exactly is done to your car? Depending on what you have, there are other things you can do to get power that are much more practical than taking the engine apart to port it.
Here's a link about porting. http://www.mazdarotary.net/porting.htm
He says you can get up to 260-280 hp, but thats with major intake and exhaust work.

 

the car has 2 3/4" catbacks and a cone filter, basically no mods.
what would an extend port run me in $?