Ok, so, im at Rosaurs looking through car magazines and one of them had an article on Jesus Padilla and his 9-second all motor 85 rx7 with a 20b 2-rotor engine.

Is this a typo? I thought that a 20b was a 3-rotor engine?

 

typo

 

that 9 second car does indeed have a 13B though.

I dont think he ever fully rant the car when it had the 20B in it because he was scared of getting banned. WHOOPS, they banned the 20B anyway

Jesus never broke into the 9s with the 20B

 

hmmm...thats funny...i was just reading the v8/rx7/convertible thread and somebody else mentioned Jesus' 20b 2-rotor engine...must be a bad rumor?

 

I dream of a 20B based 2 rotor engine.

Just think of it... the front rotor and rear rotor of a 20B. THREE bearings. E-shaft whip a thing of the past (or at least minimized a good deal) Two sets of tension bolts. With a peripheral port the difference in intake ports (the rear would have two large ports instead of one large and one small) wouldn't matter because they'd be filled in anyway, as it should be.

The custom E-shaft would be a tad bit of a bitch, and for the bother there are three-bearing conversions that you could probably set up more cheaply.

But man, the fangle factor would be *killer*.

 

I know Jesus Padilla(trying not to brag), everyone in me & my fathers circle of friends and those who are hispanic know him as Kilo. to clarify this, Kilo's motor was based on the 20B using the housings and rotors. which is why i can see that those who looked at his motor see the 20B inscription but then also see theres only 2 housings. he's gonna hook me up with some new u joints for $30 that he also used in his Datsun race car and his 85' GSL-SE racer. but he did used to run a true 20B and as everyone knows didn't crack her open so he could be competitive(err...dominating) but with his "2-rotor 20B" he runs faster than his 3-rotor. but what an upset this past summer was when his tranny broke in two. if that didn't happen he wouldve still been #1 in points

 

he tunes here in orlando at CFT (central florida turbo), rolo is his tuner....never met him or seen his ride but its a 2 rotor 13b...

 

Please explain.

I've never seen a diagram or a torn down 20B, however from Jeff20B's old avatar (Side view of a 20B) I'm assuming that it's a plain 13B with a wonky eccentric shaft that puts the two rotors 120 deg outta phase rather than 180 like the standard 13B... Then there's an extra rotor slapped on the *** end and short tension bolts that attach that one rotor housing and actual rear end plate to the 13B's rear plate.

That mid/rear plate between rotors 2 and 3 always looked funny compared to the plate between rotors 1 and 2...

Dual stage tension bolts would be kinda nice... You could rebuild the rear rotor independant of the front...

Perhaps a two rotor with the threads in the center plate and tension bolts through either end could work...

You wouldnt be able to tell it's *** from it's face... Weird.

 

The "wide" side housing (with all the tension bolt threads and the bearing/stat gear assembly) is between 1 and 2, not 2 and 3.

So the extra rotor is slapped on the front end, not the back. The front rotor has stubby little tension bolts that go in through the frontmost side housing.

If ya think about it, that kinda makes sense. The slide-on eccentric should go as far forwards as possible so the rest of the engine doesn't have to power through it.

 

thanks all for the clarification...i can now see why they would call it a 20b 2-rotor...even though there's no such thing...

 

This is my desktop background. It may help you Pele.

 

I don't know if you guys knew but he has two identical RX-7's. One is the old 20b one that he used to run before being banned and the other with the 13b. I didn't know until he brought both of them out to the lakeland track when I was visiting a friend down there.

 

I belive there was such a 2.0L 2-Rotor Engine. It was designated as a 20A if I remember correctly.

 

you dream of a 20b 2-rotor? The rotors would be such fast bastards it would probably only rev out to 6k. I do want to see if the rumors are true about the 16g maybe going into the new RX-7. stock 300hp I believe.

 

I bet it was a 4 rotor 10A.

 

Mazda probably wont put anything different into their 'new' rotary powered cars. The costs of making all the parts would be too great. Thats why we never really saw anything more than a 12A, 13B and 20B. There were tons of other Rotaries, but their runs were limited due to the costs of manufacture.

 

I read that the plan for the 4th generation Rx-7 is to be another twin-turbo'd 13b and they will be looking for 350hp stock. Their main goal is to make the engine last longer, so they are doing a lot of research and development on the longevity of the moving parts in the engine.

 

My goodness, this seems to be the thread of "I heard this" and "I think this" and "I know a guy who knows a guy whose uncle's mechanic's gay hairdresser's dog's groomer's friend knows something about this and I think I heard it this way..."....

Jon

 

The "big block" twin-rotor engine was actually the 21A and was rated at 180hp. There was also a 15A engine that was to be an option in the Rx-4 and Rx-5 (Cosmo) but unfortunately both these engines were scrapped.

 

Don't forget the 10A.

 

Duurrr, daarrr, read again...

 

Ya thats the one Im thinking of the 21A. Thanks.

4th Gen RX-7 13BTT? I suspect it will be an evolution of our new found friend the renesis engine. I still dont have a clear idea on how this Side Port exhaust system is supposed to work. Mind you I havent really looked it up much since the chances of me owning one are the same chances of me winning the lotto.

 

Guru motorsports makes a 2 piece eccentric shaft for 12a's and 13b's. It allows you to rev (with the other neccessary mods like apex seals, hardened stationary gears, race clearencing, dynamic balance) to around 13,000rpm. I think they were making roughly 350 hp on a N/A 13b.