Black_Adder

I recently contacted someone who has a carbureted RX-7 racing engine for sale, and is asking very little for it. I don't know the exact model of the engine, but I assume it is a 12A, which has been rebuilt with some high performance parts. I am waiting to contact the seller again with the information for my car, a 1986 RX-7 GXL. I was wondering if it would be possible to install this engine into my FC car, and if it is a good idea. I was originally looking for a 13BT to swap into the car, but if this engine can be swapped I would rather use it so I wouldn't have to find another engine.

Thanks.

joeylyrech

iTrader: (11)

no

Evil Aviator

Yes

No

Dillon

Putting a 12A in a second gen. is hard and not worth it (less power).
I think the 12A mounts from the front were the 13B mounts from the bottom
I think one person did it on the forum but im not sure who.

Black_Adder

Well, that's too bad. The engine is apparently newly rebuilt and still sitting in the shipping crate.

Turbo II Rotor

iTrader: (2)

Maybe you should find out if it's a 12a or a carbed 13b first.

myersprostatus

iTrader: (2)

trciedk out 12a=stock 13bt

Black_Adder

I wasn't aware there were any carbed 13B's. I thought they were all fuel injected, but I am pretty new to RX-7s, so I wouldn't really know anyways. Maybe there is hope after all!

ramses666

iTrader: (1)

Does the peripheral ported race engine come with ear plugs? If its not a PP then its not a race motor. Hard to be streetable, but possible. The cops will be laughing all the way to traffic court What are you thinking about? If it's for racing only I could see it as a possibility, but why? are u a cheap bastard? Sorry if I'm being a dick

Ramses666

Black_Adder

Take it easy man! As a matter of fact I don't have a lot of money at the moment. I'm in college and all I have is my measly tuition to pay for an engine. If it isn't the right engine for my car, then so be it. I'll wait until I can afford a proper engine to swap into the car. I don't know the details about the engine at the moment, and I'm not super experienced with RX-7s, all I'm trying to do is find out more information. The thought of a cheap racing engine sounds great in theory, but I never said I was buying it.

Evil Aviator

The term "racing engine" implies that there is something different about the engine vs. a stock engine. Sometimes the original 13B fuel injection system is replaced with a carburetor system.

That's not true. Race motors can have any type of porting, including stock. It all depends on the rules of the race class.

ramses666

iTrader: (1)

Sorry about my defeatist post. Typically 12a racing engines swapped out normal housings for peripheral ported ones as well as different rotors.

These are what whetted my appetite for rotary engines back in the early 80's(sorry, I'm old). They were the absolute quickest things I ever rode in. RX-3 with a rx-7 racing engine.

This was in 1983. I wish my NA 88 had a performance level equal to this, but alas its not to be. This original encounter has so totally skewed my perception of quickness that I'm incapable of satisfaction with my lowly NA.

Wow & alas if only the mighty Mazda gods had given us a 20b as an option for our cars as was meant to be we wouldn't be strangled in the everlasting quest for power from only two rotors. It's not the manufacturers fault, but that of our MIGHTY government imposing strange taxes & fines regarding such strange and abnormal things as tariffs and penalties for mileage vs. displacement.

The history of the RX-7 reveals that the original 2 models had 20b's(3 rotors) in them but our government denied them the right to offer these for sale in the US.

It's strange that now we have to make pounds out of pennies with the little resources avaliable. We should have had all 3 rotors to start with for a serious sports car, but surprisingly we have overcome. It speaks to the american spirit of innovation to develop the performance of these 2 rotor engines to surpass the original development of our japanese inventors.

Again.... I am sorry to assault our members with my diatribe, but history and the future demand that the truth be told.

Ramses666

Turbo II Rotor

iTrader: (2)

WTF ^^ Off topic rant.

Evil Aviator

I have some documentation on the design of the FC RX-7, and it was originally designed for the 13B. However, there was at least one after-production FC 20B test bed.

Back on topic, your comment on the race engine does actually have some relevance to this thread. If the engine is, in fact, peripheral ported, it would make a horrible daily driver.

Black_Adder

On the topic of the 20B engine, how are those for swapping into an FC? I have noticed a couple for sale on a JDM import site, but they are pretty expensive, over $3K. I also found a 13BT on the same site for $990, so I might end up buying that one.

Black_Adder

Anyone?

red_dragon

iTrader: (10)

afaik, either swap will be rather involved. 13BT will bolt in but you're going to have to/want to change the drivetrain to TII and grab a TII ECU etc. 20B is way more involved...you'd probably have to get a standalone and wiring harness etc. So neither swap is cheap unless you have all the TII stuff to begin with. It is probably cheaper to buy a TII than to do the swap.

dot_txt

iTrader: (1)

The 20B swap is expensive. The 13B Turbo swap is less expensive but more expensive than you would think. I just swapped in a 13B Turbo from tigerjapanese.com and it cost me $1000 to ship it to Chicago. Then there are all the extras you have to buy to make it run right which are another $600-$1000 easy depending on what you do.

You can use your existing N/A Drivetrain and trans but it is not always recommended. You will need your Trans, Cluch, and flywheel to do it with the existing drivetrain. Also you will need to pick up an S4 engine vs. S5. The swap from S4 N/A to S5 Turbo is a pain.. possible... but a pain.

Heres a link for a Na to JDM TII swap.

https://www.rx7club.com/2nd-gen-archive-72/my-na-tii-jdm-swap-635663/

Good luck whatever you decide.

Black_Adder

Thanks a lot for the info. I have already done a lot of reading on the subject of swapping a TII motor into an N/A, and I think that is what I want to do with the car. I have been inquiring about swapping a WRX STI engine into my daily driver, a 1997 Subaru Legacy 2.5GT, and it could cost between $8-15K! So $3-5K for a turbo RX-7 swap doesn't really sound so bad. I paid $500 for my RX-7, so I'm not sure if I should buy another and use this one for parts, or spend a bit more to fix this one up. I plan to make a post with some pictures to get some opinions.

Also, back to the original reason for the thread, I'm still waiting for the engine seller to return my call, but I doubt it will be the right engine. It sounds like he has a few cars sitting around his property. Maybe he'll have a TII that he will part out....

Evil Aviator

The 20B is a real pain to swap, and usually costs about $10K to 35K depending on how elaborate you want the swap, how much work you can perform yourself, and how cheap you can get the parts. We have a 20B subforum with a FAQ page if you are interested:
https://www.rx7club.com/20b-forum-95/

The 13BT is an easier swap, especially if you can find an 87-88 engine that will be more compatable with your current car. Personally, I would rather use an 89-92 13BT, FMIC, and a budget standalone EMS (Microtech, Haltech, Electromotive, Wolf, etc.) that has local professional tuning support rather than dealing with the crusty old stock wiring harness and horribly outdated stock computer. If you plan on increasing the 13BT output above the stock level, you should really upgrade the entire drivetrain to the TurboII specs or better.

I think a 12A engine would be an effort in futility.