Help with engine swap decision
 

I just recently bought a 87 GXL for $100, because they were moving, and the car doesn't run, and they just had to get rid of it. Everything in the car is in good shape, only 200k on it, but the motor is definitly shot, loses all compression right after startup (revs to 5k, then just dies), and I'd like to put a new engine in it, and use it as my daily driver (my fairlady will handle the night driving quite well.) I was wondering what would even be worth putting into it, simply in terms of cost of the engine. I've put an H22 into a friends accord, a B16 into an EK civic, so the labour part wouldn't be a huge issue. But i'm new to the rotorheads, and wondering what would be a decent engine, since i'm not looking for anything that powerful in the first place.

Or even, now that I think of it, would it be worth it to rebuild the 13B that's in there now, or have someone professionally do it?

Well there are some die hard rotar heads here and V8 Rx7 guys too....so thats a pretty open question that will pull some very biased opinions. You should read as much as possible on here and form your own opinion before everyone elses opinions is shoved down your throat.

Yeah, my opinion is that you should have your own opinion.

The thing is, it's really a tough question of what YOU should do. You really have to consider YOUR budget, YOUR skills, and YOUR willingness to do what's necessary to fill in the gaps. Like, if you know nothing about rotary engines, you're going to need to do a lot of reading before doing anything else if you want to rebuild it yourself.

Now in my opinion, since you said you don't need anything fast, I would rebuild the rotary. It sounds like it should run fine after a rebuild. Perhaps you might want to do some internal inspection before buying a rebuild kit. If you can just rebuild the engine and get it running good, it'll be a lot cheaper than swapping something else in there.

Easier, cheaper, more potential to the average guy with the average budget = V8
Purist, but more expensive, not as insensitive to bad tunes, same potential but needing expertise and/or money = Rotary.

Pick and choose wisely.

I think you missed this part:

No way a V8 swap is going to be cheaper than simply rebuilding the rotary.

Drop in a new 13B keep everything else.

I concur. Unless you have a V8/tranny sitting around, and can fabricate, rebuilding/replacing the 13b is much cheaper.

Until it pops again.

If you're popping stock N/A 13Bs on a regular basis, you need to either learn to put the engine together properly, or remember to put oil in it.

I'm a V8 guy, don't get confused; I've worked on 10 different V8/RX7 swaps personally. That doesn't change the fact that an N/A 13B is a good engine for it's uses, just don't expect much power out of it.

please, keep rotaries in RX7's, you will ruin it. :cool:

Hahaha, aren't you the guy who doesn't even have a car?

Oh well, even if you're not, stop spreading misinformation.

Ecstacy: Unless you are looking for something ridiculous fast, don't spend the money buying all of the parts (or fabricating them yourself) to stick a V8 in there. You'd be much better off just rebuilding the 13B. In this situation (supposing once again that you don't want something that will blow doors off the majority of street cars out there), it would be silly to attempt a completely different motor swap. Just take the 13b out and send it to someone for a rebuild or, even better if you're not looking for any extra performance, just buy a $2500 Mazda Reman 13B and call it good.

PS: Don't listen to the people who claim that rotaries fail often. You have to be dumb (I am one of the dumb ones, I admit) to blow your motor, especially if you haven't done anything extensive to try and suck more power out of it. If you buy a remanufactured engine and do a clean install and take good care of it, it will be good to you.. just like any other car.

honestly if you go to grannysspeedshop.com you can really see what it'll run ya. Plus think of practicallity and your purpose and how "easy" it'll be changing plugs, wires, oil filter, or any main seals on it.
but if you want speed go v8 cuz the most u can get from a full bridged 13b 6port is prolly around 240ish but she'll move.

I may be a newb, but I can also state my opinion as well...personally i'd stick with the 13b, but thats myself...V8's are fast and fun in a RX7, but ruins the rep that they have...Built on what wankle designed, so i'd stick with it....that way you can try to convince people you dont have pistons...lol (i have to do this ALL the time!!)

what? no piston's?

it's up to you really.

I am definately a V8 guy. I am also definately a rotary guy. I love the power, sound and performance of a healthy v8. I grew up on them. I also know that the N/A 13B in our vert starts every time, hot weather or cold, and runs smoothly, and cruises nicely. It cruises the freeways at 80-90mph without effort. I also know that in it's current state, the 13B is not what I would call a high performance engine, like say a turbo rotary or a v8. My 7000 lb truck with 6.0 L will outrun it quite easily. But the car drives nicely. Will I put a v8 in it?

I would like to, just because I like different stuff. Alot of diehards would say that Rx7's are different. Well this is true, but I like to have MY Rx7 different than most others.

Like has been said already, list your priorities for the car. What do you want to do with it? Everyday driver? Stock 13b should do you fine. Many other stock cars will run away from it, if you want to race them. The 13B is not what I would call an economical engine. Ours gets a best of 18mpg. That is for 1.3 Liters. My 6.0L v8 in 7000lb truck gets 13mpg. Thats 4.7 liters and 4400lbs more for only 5mpg.

Swapping a v8 is alot of work, can get expensive, but the gains are alot of power (torque) and better mpg(most of the time) unless you are getting truley radical with the v8, and something that will draw the crowds when you pull in.

You said you really weren't looking for alot of power so a stock rebuild sounds like it would fit your needs. Like what has also been said, go to the section that supports your generation, and read through the threads and see what problems people have with theirs and what they have done to improve them. You can also go to www.torquecentral.com and see what people have had problems with and what they have done to overcome them.

Later,
Bill

find the real issue
 

Since it starts and runs to 500 it would seem that a bit more diagnostics would be worthwhile. Maybe some decarbonizing would bring the engine back to life.
search for carbon removal