Is it very expensive to put an 20B in a 1st gen(aside from the motor) like ecu, motor mounts, etc. Do you have to modify the radiator, is the 20B longer? What's the displacement gain? i am probadly going to replace my 13B and i want more rotor so if it isn't too much drama i'll go wit 20B

 

I know most people will have more knowledge about this than me, but here's what I know.

Yes. Very expensive. The motor itself, and the parts for it. No. It's not easy, unless you're a really really awesome mechanic. I think if you place it in the normal location, that extra 6 inches leaves no room for the radiator and junk, so that all has to be moved.
But the only way I've heard of people doing it to first gens is moving the engine back. You have to cut the firewall, move the tranny back, and then all the other crap. The driveline will need to be shorter. And I'm sure the stock rear end would snap pretty fast with the amount of LOW RPM POWER that the 3 rotor engine has.

If you payed someone to do it for you, the power gain would be pretty decend I would imagine

Please people, correct me because my knowledge is pretty sketchy about this stuff.

 

How much money is expensive? How deep are your wallets? I believe the entire swap will cost about $15k, give or take $5k, to put a 20B in a FD third gen RX-7. The difficult parts are putting in the motor and tuning it. Some problems that might arise are... well the motor is really long so you might have to move things forward or cut into the firewall. Also, the steering rack poses problems with other swaps, so it might cause problems on this swap.

Well the gain in displacement is one rotor or about .6 L.
The 20B puts out 280 hp and 296lb/ft in stock trim.

All said, I think it's possible, but it will be expensive... at least in my definition. You might as well buy a 3rd gen for that money!

Anyways, I'm done ranting. Good luck on whatever you choose!:

 

as directfreak likes to say (at least i think it was him)

the general rule on something like this is : if you have to ask, you cannot afford it.

most people that i have talked to have said that if you cannot through down a deposit of about 20k, then donot bother.. it is not a cheap swap.

 

ok, thanks for sharing your knowledge . I diddnt realize that a 20B is a major thing, i thought it was a relatively simple swap, if it costs that much and is that complicated i thing i'll stick wit my 13!

 

as for cost you have the engine 2800-7000 I have seen them for. haltec ecu about 1000 used. add about 2000 more for fuel pump and lines, hoses, belts, wiring, fluids, custom exhaust, new rad, ic pipes, ic, ect... bla bla bla so on the low side you are talking about 6000 with you doing all the work if you get things cheep and dont have to rebuild the engine. plan on about a year for the project. do you have all the tools, skills, knowlage to do this? there are places that will do this for you for about 12,000 I have seen one that was done the owner said he did it him self for about 5,000 buy buying a front clip and was lucky to have gotten the computer with it.I find it hard to belive for 5 grand. hard to do? that depends on your skill level. price being a object I am duing a 13bt swap. you could do a 13re or 13rew a lot less than a 20b. a 20b does look sweet under the hood of a first gen.

 

so... hate to bring up this subject.... but... how much does a 20B weigh as compared to a 302 with aluminum heads, etc?

'Cause really... with 20K you could have one f*ckin fast 302 - 7 with a nice paint job, new custom interior, nice rims, full suspension setup, headers, intake, carb, cams, lifters... etc etc.


*puts on flame suit and ducks and runs*

 

nukluk !!!

 

yeah this has got me wondering as well. How much more does the 20b weigh?

Would it completely ruin your handleing like a v8?

I thought about it, and one of the reasons why our cars handle so well is because the engine is pushed far back. Wouldnt the car handle nearly as well if you cut into the firewall to mount the motor? This would keep the weight in the center which sould make it handle fairly well.

 

yeah, but in the same boat.... a 302 sits pretty close to the firewall.... and wouldn't the extra rotor, housing, intermediate plate, e-shaft length, intake, carb, etc all add up to the ~200 pounds more that a 302 weighs over a 12A or 13B?

Someone needs to get a scale, and a 20B, and a 302, and a 12A, and a 13B Cosmo with turbo....

 

the guy I bought alot of my engine parts from was going to do a 20b swap on his 84gsl.

I didnt get to ask him much but he said the motor was alot heavier, not because of the extra rotor but because of the second intermediate housing (if thats what its called)

However if I remeber right, its was some where ~100 pounds. I'm probaly off though. But thats still not the 200 more that the 302 weighs. I also didnt realize the 20b made that much torque. More torque than hp. Something I've never seen in a rotary!

He ended up scraping the project because he didnt have time for it.

 

The guys on this board or should I say gurus, have trouble with this swap... It gonna run you upwards of 10 - 12 grand to get one in there and running, and thats if you run the motor with the stock twins etc.

 

search for 3rotor on the boards... he has done this swap, and he happens to have a very nice 3rotor cosmo imported from Japan. Needless to say, he has lots of money, so...

 

hmm.. but think of it a different way...

What kind of cool car could we shove a 20b into that *doesn't* come stock with a rotary engine? I think it'd be so cool to get a fast boinger car, swap it's engine for a 20b and race others with the same kind of car It'd be cool watching people who have huge mods to their boingers look under the hood of the 300+hp monster that just blew their tires off and see... a rotary?!

Just my $0.02 (Canadian of course)

Jon

 

there have been a couple of threads in the second gen section it seems that stock s4 t2's weigh, between 2800-2900 stock. my 20b t2 wieghs 2860, with a full tank of gas, stock 20b, stock 20b turbos. i got rid of the ac and ps, but its otherwise stock, so the 20b isnt that bad

mike

 

I think it'd be funny to put a 20b into a Mustang GT. I'd do it if I had lots of extra money floating around. (Which I don't....)

 

hey, did you know that in 1976 chevy made a prototype Corvette with a 4 rotor at 300ci. They droped it do to gas milage, but they actually made 2 of them in full prodution trim. I would love to meet the guys who own those beasts, they even had a cd of .30 and were a rear mid-engine design w/ gullwing doors. Man what I would do for a ride in that beast, or even better, to drive it.

 

Now People first off u do go puttin a mazda rotory enging in anything but a mazda that's just the way it should be.... second if your a hardcore tuner the 20B engin should be no prob i'm planning on doing it real soon that's only because i got nothing else to change i got suspension and breaks and all that other stuff done so the car can handle it.... yes the engin is bigger I will be cuttin into the firewall to keep the center of gravity all good .... But I warn people now if your planning on doing this u need money and u need to know what your at

 

A Mustang! Exactly the kind of car I was thinking of...

If you could put a full-out turbo'd 20b into a mustang with all the mods, and beat out some guys with tricked-out mustangs.... Wouldn't you love to see the look on their face when they're describing their mods, and you just open the hood to a 20b?

Jon