I did a search on this but couldn't find anything so here goes...

Can you directly swap in RX-8 rotors into the 20B? What are the RX-8 rotors compression ratio as well?

I don't want to do any machining or modifying/clearancing, etc, I just want to put them in like the 86-91 NA and Turbo rotors.

What about the 93-95's? Thought those would work as well.

Just asking because I have the motor apart and am exploring options.

 

the rx8 rotors do fit in the 13b, the only problem with the 20b is that theres no balance weights for a 3 rotor renisis. on a 13b you can use the rx8 rotors and cw's and be done, but you cant on a 20b. the alternative are the 89-91 na rotors, as they have the same balance wieght as the stock 20b rotors

 

WHY???


-Ted

 

Why???

Well, the theory was lighter rotors & thus less mass, higher compression and 40% less cost each than 20B rotors (per the Mazdacomp costing I get). Good enough for ya?

No big deal, I'll just go with the S5 NA rotors like I was planning.

 

On a side note, the 20B rotors are the same weight and compression as the 13brew, right?

 

89-2002 is the same balance wieght.

 

Cool, that's what I thought. Just figured I'd make sure while we were on the subject.

 

Do you think you could redrill and rebalance a Renensis rear counterweight? It may not be a good idea due to there being two key slots at that point. I guess you could fill one of them in? Same for the front counterwight. Do you guys understand what I'm talking about?

 

May be easier/safer to mill out your own piece instead of trying to fill a slot in with weld, then get the piece heat treated after. Problem would be trying to find out what process they were using (T6, T7, etc) for that alloy.

 

I called Mazdacomp today and they gave me the name/number of a factory Mazda rotary engine builder who can supposed answer all these questions and has done this kind of thing for years. I am having my local shop/engine builder call him so they can work out the details. Will post if anything interesting.

 

Has anyone had problems with the big metal plate cracking.the one were you fill the oil into the engine on a 20B?what can i do to resolve this problem?I got a 20B on my s-10 blazer and this weekend it happened to me.

 

The intermediate plate? That's not good.

 

I know it aint good but need to find out what to do if i should pin the engine or what?

 

Jose, what series engine do you have?

 

pinning the engine is defenetly a good idea

 

Depending on how its cracked, the engine coolant might have frozen

 

Don't see how this has to do with changing rotors in the motor, get your own thread...

On a side note, my 1st and 2nd intermediate housings both cracked from water expanding over the winter... i.e., why the friggin' thing is apart now.

 

sorry to hear that , oh yes and sorry bout hyjacking the tread