Hi everyone, I beleive I read somewhere there are 20b's shorter than 26inches of the normal length. Does anyone know of the post? I'm also told there are shorter "E" shafts that one could use a 13b parts. Also anyone know of a book of tape on high performancing the 20b?
fvercher@charter.net

 

If it is, it's NOT called a "20B".


-Ted

 

Let me make sure I understand your question..
26 inches shorter than normal 20B short block?? Have you even looked at a 3 rotor engine? 26 inches (2 ft 2 inches) shorter will make it one rotor engine.
2 rotor engine might be 26 inches long.

 

Okay, what you are talking about is a 3rotor using 13b parts it's call'd a short block 20b. I have seen pics of some, they are mostly done in Austraila but a custom E-shaft is need'd and if I'm not mistaken it costs more than just buying a 20b.

 

What?? Most of the 20B parts are similar to 13B parts. Except E shaft and one "special" plate.
So, I'm confused to what you are saying?? Also, 26 inches is alot.

 

20b's have a much different front plate, center and rear, a 13b-rew can be "mod" to work as a rear plate, then the counter weights are different front and rear, 20b long tension bolts. Not to mention the special stationary gear in the thick iron. Do a search and see what I mean. a "13b" 20b short block you speak of, would be about 2" shorter and 15-18 lbs lighter, which isnt much for the extra cost and weaker design.

 

There is a website www.evil7.com or .net that had a 3rd gen being fitt'd with a 20b short block motor that was shorter than the factory 20b and made by putting 13b irons and housings together with a custom E-shaft. I tried to pull up the site but I can't find it. I'll keep trying

 

sorry for the cross post, but read my reply's here. its too much for me to retype here
http://www.nopistons.com/forums/inde...pic=54730&st=0

 

some excerpts from other thread:

jeff bruce makes custom 2, 3, and 4 rotor e shafts and modifies center plates for the building of these engines. you can orger the 3 and 4 rotor shafts in short or long config. guru and kiwi re sell kits made my jeff bruce
and his precision engineering company

hers a quote from hitmans site:


Custom made 3-rotor based on RX4/5 13B components, Custom made Crankshaft, 12A RX7 centreplates with one modified to take a stationary gear, RX-5 end-plates and rotor housings. Custom parts made by Jeff Bruce.

heres a link to the engine specs
http://www.hitman.hm/engine.htm

heres a link to the car buildup. again notice that this 'short 20B' was built over 6 years ago.

http://www.hitman.hm/rx7.htm

jeff bruce's contact info is on that page too, im sure its changed since then, but you can buy the stuff from guru or kiwi now

 

Okay I found the site of the shop that built the evil7 car. I was alittle off on what parts are used. You know on a factory 20b, the iron that seperates rotors 1 and 2 is thicker than the iron that seperates rotors 2 and 3, which makes the exhaust manifold look off center. Now go to www.cityperformancecentre.com click on customer, then street cars, then Allistair's RX-7, I think it's the 10th photo down counting across, but you can cleary see that the irons are the same width, which leads me to believe that instead of using factory front iron they used 2 factory 20b rear irons, which would make it shorter than a stock 20b. There is also a pic of the custom E-shaft and manifold. Check it out.

 

This is the company/person who makes the "short" 20B http://www.kiwi-re.com/ front and rear irons are stock and the two center irons are just intermediates. They get rid of the stock 20B intermediate the one between the first and second rotor which is really wide and replace it with an intermediate plate like the one between the second and third rotor which is thinner. And it will no longer be side intake as changing the thicker intermediate to a thinner one would throw the ports off. So the motors are periferal ported. This is the engine that Siquel/Major League RX8 are currently running and have ran 6.81@200mph with.

 

Hello everyone, thanks for your response. I am not a rotary mechanic, but I choose the three rotor as my platform. I'm told the engine is 26 inches long, but I really don't konw this as a fact. This engine will go into a VW, with mods done to the interior behind the back seat. Because of the length the three rotor is, I will have some fitment issues. But cutting and grinding anything can be made to fit. I know the 13b will fit with some room to spare. I have just seen the overhauling the 13b for Atkins Rotary. So now I know somwatt how it ticks. If I may be allowed from time to time ask questions I feel are note worthy please be patient

 

It's blasphemy to call anything other than the Cosmo 3 rotor a "20B".
If it's not out of a Cosmo, it can't be a "20B".

Yes, it's a "3 rotor", but not a 20B!

Mazda made a racing 3 rotor called a 13G.
We do not call this 13G = 20B. :P


-Ted

 

I agree!!

SO, does this hybrid short 3 rotor have 2 piece or one piece E-shaft?? I'm guessing one piece. I've heard 2 piece shafts are stronger than 1 piece.. I'm I wrong?

 

I think kiwi-re can make them in one or two piece.

 

I e-mailed Kiwi-re, but no response. I quess they get pumped for inor all the time. I'm not sure if I but the "E" shaft and get other parts for a start. Or plan two if to buy a engine from a engine core junk yard. from what I can tell in Los Angeles I have found one for 3300$ with out the turbos. So which is the best way to go?