I wanted to see if any body has seen a 13b iron on the rear and a 20b iron for the front iron. This is how my motor is. I wanted to see if anybody has done something like this and how it would be for power. My motor is a two rotor and it came out of my parts car that I bought then sold but keep the motor. I have not fired it up yet but I am going to keep it.

 

The rear 13B has been done on a 20B but you can't use the front 20B on a 13B.

 

pictures?

 

I will post some pictures of my motor. I was looking at it tonight and the front iron is a 20B and the rear iron is a 13B

 

So did you plug all the tension bolt hole in the front iron? The FD front iron is much stronger around the oil gallery why do it?

 

May as well mention that two of those bolt holes are over-sized. The porting is also drastically larger on the 20b intake runners then the 13b-rew

Here is a 20B front iron, just so you have something to compare your engine to.

 

I did not build the motor the guy that I got the car from told me that the rx7 store here in Ohio built the motor with spare parts that they had laying around the shop.

 

Here is a picture of the motor

 

That is not the front iron, it is a rotor housing. There are a few differences between the 13B and 20B housings. Exhaust sleeves being one of the large ones, but that can be swapped for a 13b. There will also be some oversized tension bolt holes.

 

who was the name of the guy i can look it up for you

 

Thanks banzai for letting me know that would be called the rotor housing. I have only be in to the rotary engines for almost two years still trying to learn all the parts names. I was wanting to know if you guys know what kind of power it would have compared to having to 13b. And for zayrx7 I will look up the guys name that had the car and let you know. I know the year and color of rx7, 1988 and it was red with a sunroof.

 

Having a 20B rotor housing will not make any difference in power output as long as the exhaust sleeve was swapped. Otherwise the flow would be more restricted on the 20B front housing.

20B sleeve vs 13b-rew

 

if its a 13b-re housing then it would have the same exhaust insert as the 20b

 

it has 13b exhaust sleves in it

 

Do you know if there was any thing else done to that motor? I am trying to decide to keep it or sell it.