I'm going to look at an 83 280z w/t-tops. no motor or trans. I happen to have a few 12a motors and trannys laying around. How difficult would it be to do a conversion on a 280z? I have a street port I think would be a nice fit. They are light weight and handle great, just like a seven. Also are roughly the same size and even the same wheel bolt pattern I think. Anyhow, weigh in........... Is this a fairly doable swap, or just a huge pain in the ***?

 

I think it's worth looking into... RX7s have an abnormally large transmission tunnel for their size, given the high distance from the eccentric to the bottom of the oil pan. That partially explains why they're such common V8 swap candidates. You may run into some problems getting the transmission to fit into the tunnel vertically.

On the other hand, there's no reason not to give it a shot. A 12A transmission isn't that big.

 

so what size tunnel is required? Any way for me to judge with a tape measure? I'd rather know before I buy. LOL How wide/tall does it need to be?

 

Just lower the engine in the front in the bay to make room in the tunnel if you need to, assuming there are no steering components or cross members in the way.

I would measure the diameter of the bellhousing, add some room for clearance, and go from there. Take a measurement from the center of the e-shaft (or transmission input shaft) to the bottom of the pan, and keep in mind that when the tranny is centered in the 280 tunnel, you will need that distance down for pan clearance.

As mentioned, since the output of the rotary is in the "center" versus the "bottom" like a piston engine, you may have some problems, but I think its possible.

Overall, I would be 85% sure it will fit, the RX7 parts are super small.

~T.J.

 

Since the older Zs had an inline 6, there should be enough room shifting the rotary forward. If you have a 12A engine and tranny put together, measure from the shifter to the front of the bell housing and the shifter to the front of the fan. That along with the height measurements should get you close.

I've seen 1 2XX Z here in town in the last 5 years. The 240 Z would be a better choice. The engines got bigger, but the Zs didn't get faster, they got heavier instead.

 

Thanks, this ones gota pretty straight body w/couple minor "dimples" and a mostly complete interior. (already removed, but included) Since the motor and trans are gone too, most of the "tear down" is done for me. For 300, I figured it's a great deal if I can get it figured out. Not to mention it would be a sweet little ride to play in. Years ago I helped a friend drop a 350 in one, but we had to do a shitload of work to make that happen. I'll measure one of my trannys and take some motor measurements for references. Plus I'll be in my 84 when I go look, so I can kinda visually gauge too.

 

83 280z Curb weight 1,281 kg (2,824 lb) 2 seater 1,356 kg (2,989 lb) 2+2

83rx7 Curb weight 2,300 lb (1,000 kg) - 2,500 lb (1,100 kg)

im sure the straight 6 and tranny are alot heavier then the 12a so i bet its a pretty good swap

i would do it even if it required a little cutting i mean its just a nissan lol

 

jumping into another project when you havent even completed your iDF?

 

LOL I take em as I get em. I've got an 85 GS 85% complete, but sold, an IDF setup I'm tryin to get worked out, a 48 DHLA I'm desperately trying to get help on, and now it looks like I'll be doin a swap into a 280zx. Lookin at 2 other rollers too. LMAO
I do have the two carbs mostly figured out, the IDF is waiting on a rebuild kit and a bunch of jets to get in. The Dellorto is a paperweight till I get someone to take 10 minutes to pull thier RB e-tubes for me. So, since the 85 is sold, time for another project. Besides, always did like the Zcars, but I'll like it more as a rotary!

Thinkin IDA on a street port for this one. That will add to my carb collection, and keep all you IDA guys from flamin me too. LOL

 

Well, I'm going to look at the 280zx probably tomorrow. If it looks anything like it does in the ad, I'll be picking it up. I think I've got most of the possible problems with getting the 12a in worked out. I'm a bit worried about the electrical nightmare though. Since I'm using no emissions and running a carb, what electrical/electronic components will I need from my seven to make this work?

 

you dont really need anything from the 7 elcetrical wise just the coil pack since you will probaly wire most your self..

things i see u wiring will be the coils/dizzy while ur at it direct fire.,alternator,backup switch on the transmission.

 

Great! Done a few v-8 swap in the past, but never a rotary. Was hoping this would be as straight forward as it seems. Direct fire was on the list for this already too. Wonder how hard it would be to wire up the 280zx's dummy lights etc. to the 12a? Should be pretty cut and dried huh? I think this will be a fun little ride. I'm kinda jazzed to get into it and get going. If memory serves, the Z cars had a pretty decent suspension already, and with less front end weight, should handle well.

 

i dont know about the dummy lights but i would just hook up a equis gauge set for water temp and oil pressure.or more.

 

sorry, I meant the stock gauges. LOL I don't care about the dummy lights. But, I'll probably end up doing a custom gauge cluster any way. tach only goes to 7k and redlines at 6k. Guess I'll just have to figure some of this out as I go.

 

Personally, I would love an old 240z with a rb25 swap. But since you have the 12a's, away you goooo.

 

Hey. I have done a 20b with turbo 5 speed into my 240z. There is enough room in the tunnel for the gearbox with the engine sitting fairly low to keep the tail shaft angle within limits. My engine is installed a long way back sitting behind the cross member and there still is enough room. With a 12a it should fit fairly easily. There is a guy who did a 13b into a 240z and has a web site (rotaryz.com) with plenty of pictures.