haha, thats sweet

I have to step over my 20B just to get to the 13B stuff. I hurt my knee the other day when I accidentally rammed it into the thermostat water outlet on the 20B. Darn thing jumped out at me.

you should put that thing on a leash or something, Jeff..

what would you need to make a 20b out of FC or FD housing? i think this might be a cheaper way to have 3 rotors. if at all possible...



refer to photo...

it's possible, but it isnt really any cheaper as it has been cover numrous times.... you will need a custom e-shaft, center plate with stationary gear, intake, exhaust and oil pan.....ect

no, its more expensive.

I plan on doing this exact same project over the next five years. I have an 86 non turbo 13b that I will rebuild and I would like to replace the 13b with a 20b and run a t78 turbo. I figured about $30k for the whole engine, whole turbo setup, whole fuel sys, and the the rest of the drivetrain. Does this sound like I'm in the right ballpark figure? I plan on grabbing as many extra parts as possible to have back ups. As for the 13b, well I think I just might try and put that in an old 65 mustang shell.

theres one going for 3.5g at the moment in nz, www.trademe.co.nz



just search 20b

I used 13b housings i was told they have better cooling capabilities than the orginal 20b housings and are interchancgeable with the 20b housings a custom e_shaft shouldn"t be needed. as far as rotors second gen rotors and 3rd gens both work. but definetly get the later model e_shaft though if you want big hp numbers the earlier ones break easier. Adam at rotary specialties in canada is a wealth of info too.

Okay, as a guy who's spent way too much on a 20B conversion, let me chime in.



A used 20B will go for around $3,500 - $4,500 depending on the series and condition. Japan2La on the "other" forum is selling a C or D series (can't remember which) for $4,500. What's the difference in series? All 20B engines come marked. The irons are marked as well as the housings (this is how you can tell if the engine has all matching numbers - then you know it's not made of mixed parts). The easiest place to look is on the rotor housings, right next to where it's stamped with a "20B" The original 20B engines ran 001 - 999, without a letter prefix. Then Mazda switched to using a letter in front of the numbers and produced A,B,C, and D series engines. The A series had a different rotor housing design that was prone to cracking. Not good. This was fixed somewhere in the early B series engines. The eccentric shaft was also redesigned somewhere in the early series, buit I think even before they made it to the A series.



So, the most desirable series are the C and D engines as they had all of the modifications made by Mazda. Bs are probably good to go also but the As most likely have the weaker rotor housings and these should be replaced if you want to make big power (isn't this what it's all about?). A lot of A series engines showed up in the states first, but now you can find C and D series.



You can use 13B FD rotor housings (don't let anyone talk you into 13B non-FD housings) and these will work very well. They actually have advantages in cooling passages over the 20B housings.



So, it's much easier just to buy a complete 20B used engine and rebuild it. If you try to make one out of 13B housings, you'll need also a thick center plate, the front iron, and an eccentric shaft. The thick center plate is impossible to find and Mazda doesn't make them anymore (rumor has it they'll start again) and they're crazy expensive. I've seen them go for over $3,000 if you can find one (I'm fortunate to have a brand new one in my engine:)). The eccentric shaft is also a bitch to find. I bought a new OEM one from japan2la for $1,800. Used ones can be found for about $1,000 but you need to make sure the shafts are not bent. Because of the nature of the 3 rotor, the e shaft is prone to flexing in the middle, thus the bent shafts. Not to be a sales *****, but I have a e shft I was going to use in my engine until I bought the new one. I'll probably sell it soon for $1,000 if anyone is interested. It's been dynamically balanced by Roger Mandeville and it came from the Pettit Racing GT series inventory.



As to the cost, $30,000 - $35,000 is a good figure to use. You'll need to used engine and an EMS to drive it. You'll also need to rebuild the engine and depending on how you rebuild it, it can be quite expensive. At a minimum, I'd use the Xtreme Rotaries stud kit on the engine as this will solve the flex issue for the shaft. I'd also pay the extra $1,000 to dynamically balance the center rotating assembly. Throw in a new intercooler and piping, the subframe for the engine, and then a turbo (go with the GT42R), you can see the $$ will add up.



Anyway, off the soapbox now. Hope this info helps.