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So you want to swap a ROTARY into your Z! (how-to)


auxilary

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ok, so dont think im trying to be stupid here BUT.. later on are you going to put 2 or more rotors on the front if it? the thing that intrests me the most about the rotor engines is that you can stack as many of them as you want on top of each other as you want

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In theory yes. In principal no. If you can find someone who makes the eccentric shaft for the right rotor count. I believe there's also a bit of work that needs to be done to the housings to just keep stacking them, though I could be wrong on this.

 

The stock motor still uses a counter weight and if you wanted a 4 rotor to fire 4 even fires you'd still need some type of counterweight. There's a guy though that built a race purpose 4 rotor who setup his motor to have 2 rotors in sync and the other 2 180 degrees offset. This allowed for NO counterweight and much faster revs, though it was rougher sounding. I think this might be how mazda setup the 787B judging by how rough it sounds anything near idle.

 

The point that I'm getting at is that it's not as easy as it looks. It can take a lot more time and effort than it's really worth in some cases. But yes it's possible, and has been done.

 

Feel free to chime in aux, i know you know way more than me about rotary motors.

 

EDIT: Here's the link to the previously mentioned 4 rotor with no counter balance

 

http://members.tripod.com/~grannys/4rotor.html

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ok, so dont think im trying to be stupid here BUT.. later on are you going to put 2 or more rotors on the front if it? the thing that intrests me the most about the rotor engines is that you can stack as many of them as you want on top of each other as you want

 

Not quite. While technically you can stack rotary rotor and intermediate housings in sequence, you need custom bolts (18 of them) to tie it all in together and a custom eccentric (crank) shaft made. There's a company in AU that manufactures these, but in short, 4 rotors are very expensive. 3 rotor 20b (2liter) costs around 4000-4500 for the motor alone with accessories and turbos.

 

Given what I learned, you cannot run a stock twin turbo setup from 13b-re, rew, or 20b-re motors: they won't clear the rails. Single or dual non-sequential turbo setup will have to be used to bring turbos up higher, and that's where it starts getting expensive for custom manifolds, etc.

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  • 2 months later...
Anymore updates on this? I can't stop coming back to this thread and then checking ebay for craigslist for cheap 13bt's. No luck so far though... What are your thoughts on boosting a NA 13b? Those I can find quite easily and dirt cheap.

 

You might want to spend the extra money and get one in good condition. I discovered a water jacket failure in mine and had to buy a whole new set of used irons:-(

 

An NA can be boosted but the compression ratio is higher for the rotors. It's been done tho.

 

Auxillary, look what you started. First me and now everyone else is copying you!

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I knew the NA blocks had a higher CR then the turbo'd blocks. Just wasn't sure it was too high. Maybe I'll just toss a thicker headgasket in it to lower it. :bonk: Really though. My local pick and pull does the any engine in the yard for 150 and they pull it and load it into your car even. Anything bolted onto it is included with the 150 besides the tranny. It's a toss up between this and a FWD SR20DE longblock and using the l-series adapter plate.

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not worth it to buy a JY rotary. Very high chance that the rotor and side housings are shot. If not from a blown apex, then from rust and corrosion etching their way into the chrome.

 

It'd be a better idea to buy a crappy beat up rx7 for ~400-500 that's still running and has good compression, pull that motor and rebuild it, part out rest of the car

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  • 1 month later...
Guest Jakor
I knew the NA blocks had a higher CR then the turbo'd blocks. Just wasn't sure it was too high.

 

The n/a blocks actually don't have higher compression... It's the rotors ;)

The turbo blocks just retain the 4 port intake instead of the 6 port intake, and remove the sleeves in the exaust ports so you can actually port them... :rolleyes:

 

@Aux: You know, a three rotor turbo woulda fit better in there. =p I just wanted to throw in that you don't need a turbo to make a rotary powerful. 200 rwhp is attainable with a 2nd gen n/a motor, and is still a big upgrade from the 180bhp that a stock 280zxt puts out. I noticed some people were just waiting to afford the 3rd gen turbo motor, but there are other things that can be done. Going with the n/a as long as you don't run nitrous, you don't even need the T2 tranny.

 

I just purchased my 82 280zxt because I blew my coolant seal in my motor (and my girlfriend was going to need a car when I got my 7 back). I figured it was time for a rebuild. It's s4 so I figure I'm limited to around 190 rwhp before my 100 shot of nitrous (keeping it well on the safe side). If I had access to a s5, I'd get everything balanced and turn 9k rpm on a streetport. Then I'd see over 200 rwhp. I guarrentee you that 190-200 rwhp with a decent suspension, and maby a 255 size tire, you'd be a top contender down at autox.

 

 

Any questions, I'd be glad to see what I can come up with. The z is my first turbo car, so I'm not too good with turbo related questions. I was running a high 14 with a cone filter, and a full 2.5" exhaust. Not bad for a 16 second car stock (amazing what rotating mass removal can do.....)

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  • 2 months later...
Guest raygorsuch
This is really really REALLY dumb lol, a true waste or time, money and space lol........... blasphemy

 

wow... 1st post. SMOOTH move NISSAN4EVER... Do me a favor and read something before you try to speak, it might help you a bit.

 

I'll be suprised if he lasts 10 posts at this rate. Oh well.

 

If you DON'T want to get baned, you'll want to study the rules of the board.

 

Did you call it or what... exactly 10 posts.

 

I have a '73 Z with a sick engine and I was considering doing this swap since I have an S4 donor car with no title and a good engine. You may want to consider marketing the engine mount since the rotary world has such a following (and because I would buy one).

 

I am not new to rotaries having owned a '79 RX7 for about 3 years, and pre-mixing isn't that bad. I carry graduated clear soda bottles full of 2-cycle oil and drop a set amount in the tank before filling up (I buy the gallon jug of oil because it is cheaper that way). At this point it is no more out of the ordinary than un-screwing the gas cap.

 

Keep the info coming as your project takes off - some of us are taking notes as we are cheering you on...

 

-Ray

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  • 2 weeks later...
  • 3 weeks later...
Guest RotaryBuddha

Great thread. I've been thinking about doing this swap for a while. Did some searches and found this place. I've been into rotaries for ten years. And owned 5 different rx7s over the time. Auxilary are you one rx7club.com?

The only thing I would like to know more about is the motor mount? Also did you rebuild and port the motor? What turbo is that? Idemitsu is the best premix IMO. http://www.mazdatrix.com/q-supply.htm

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i used to be, but for some reason my account exists, but not able to post/send PMs. I reregistered last night.

 

motor mount was custom built from scratch. Motor wasn't rebuilt by me, but it looks like it was rebuild in hte past judging by the amount of silicon squished out from between the housings. Turbo is a garret t04s, .7 cold, .84 divided hot, 60-1 and p-trim.

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Guest RotaryBuddha
i used to be, but for some reason my account exists, but not able to post/send PMs. I reregistered last night.

 

motor mount was custom built from scratch. Motor wasn't rebuilt by me, but it looks like it was rebuild in hte past judging by the amount of silicon squished out from between the housings. Turbo is a garret t04s, .7 cold, .84 divided hot, 60-1 and p-trim.

 

I'm on their under the same name RotaryBuddha.

 

Yeah too much silicon squished out the side can be a bad thing too. I would just do a compression check just to make sure. I would hate to see a project like this get complete and then the motor won't turn over because of low compression. Here is a link to two different ways of checking compression.

 

http://www.rotaryresurrection.com/2ndgen/tech_compression_check.html

 

With a good street port and that turbo at 15-20 psi you should be looking at least 400rwhp.

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