engine of choice
 

The engine of my 85 rx7 is busted.....that means time for a new engine yippeeeee!!!
I wanted to know which engine is able to FIT and best performance for my car. I'd like to have my car running for a much longer time so I've decided I would install my car with a new engine, but not fixed up. I wanted to know what engine would be best for the rx7, an engine from a 94 rx7 or maybe 92? I don't know much about cars, so I NEED HELP!!!!! any information would be most helpful

hmmm... man I wish I can give you some advice but I heard the TII Engines are nice. Beside that not sure what would be best engine for you. I guess it all come down to a personal pref. However there are good experts in here that would help you better. I am still trying to figure out what would be a very good engine for me too and upgrade. Looking for 200HP or 300HP most I guess I will have to search around for info.

Good luck on your decition.

do you want to go turbo or NA?
is the car gona be a daily driver or track car?

I would suggest a 4-port 13B. Parts are plentiful, usually less $$$ too. Easy to work on/rebuild. Street port the 4-port and a decent carb/exhaust setup you would be at 200-225 HP at the flywheel. The thing would last forever, as long as you maintain it, the same goes for anything though!

20B with a T78 and stand alone. :mspank:

i mainly want to keep the engine as is cuz i'm kinda on a tight budget and mainly used for everyday use

S5 13B with a sidedraft carb.

Since you don't know much about cars and want something that will last, it's hard to beat a 12a for simplicity and longevity. They are a little short on power when compared to the REW's, but you pay for that extra power with higher purchase price, higher parts price, and higher maintinence. It is also not an easy swap.

You didn't say what engine you have in the car now, but both the 12a and 13b can be built for more performance and hp.

My SP 13B 4 port just went after 10 years and 120,000ish miles. Pretty damn reliable. Daily driven with about 215flywheel horsepower. I would definately recommend this is you want an N/A motor. If you want stock turbo'd rotaries, the TII would be easier, but the 13B-REW from the FD would be very cool.

I really like my "street-ported" 12A.

225 rwhp,
idles at 400 RPM with a Weber 48 IDA... Pulls with power beyond 9K.

would make an awesome daily driver if it could get better fuel economy.

If you want to go the 4-port 13B route...

I have an old 4-port crate engine. it has been used maybe 8K with a proper break-in. this is the engine that would have came in the 74-75 Repu and RX-4. (big exhaust port).

I have it available for $1000 plus shipping. I have a Weber 45DCOE set-up jetted and ready to go.... and an RB Header to help complete the swap... if interested, send me a PM.

12A all the way, stock or modified, you can't go wrong.

225rwhp from an NA 12A with a "street port"? Got a dyno sheet? I also find it hard to believe that a ported motor would idle smoothly at 400RPM, considering a stock port doesn't even idle that low.

stop trying to be an E-thug. Instead of accusing him of lying, why don't you ask how he got those results?

And while you're at it, why don't you ask him about the TII engine he built for a guy named Mike in Indy that idles at 150 RPM...

Transportation or Hobby?
 

If are not an experienced gearhead, you should be looking for reliability. the advice of staying with a 4 port is good advice, either 12a or 13b. You would have to modify the front motor mount for a 13b because it is a bit longer. I took a 12a, street ported the secondary intake ports(using the RB template), cleaned up the primaries and the exhaust. I made an adapter for the manifold and installed a stock RX-4 carb, RB exhaust header. It makes 130Hp to the rear wheels, which is all you need for a fun daily driver. A completely stock 4 port 13b with the same exhaust will give similar performance.

Don't let people talk you into an aftermarket intake system and carb, Webers, Holley or whatever unless you are looking for a new hobby. The stock carbs run well hot or cold and will avoid a lot of hassles for you. And you definitely don't need a turbo.

www.cardomain.com/ride/646433

I too find this a bit ambitious.
All "clean85owner" is asking is for a dyno! Fair enough. Too many unsubstantiated claims on these forums.
I too would like to see a dyno as if this is so it must be the highest HP NA streetport there is bar none.

Oh, and "Another Driver" I would build a nice 12a Streetport.

Calm down there, dude. I'm just asking a question. I have never heard of a rotary idling smoothly at such a low rpm, much less a motor with extensive porting.

Just because I find something hard to believe does not mean that I am trying to be an "e-thug" and "accuse him of lying."

God damn. You would have an aneurism if you went into the Kills section, man. People call BS there all the time; are you going to go in there and call all of them e-thugs, too?

i'd have to go with a streetport 12A, myself. it will give you all the benefits of a stockport, but with increased power and (if you get it built right) increased reliability. it's simply and won't break the bank, compared to a 13B, 13BT or 13BREW swap.

mine idles great at 500 RPM ... stockport 13B with Dell'Orto. :) when i'm done with my streetport buildup, then i'm planning to accomplish the same idle.

however, the "E-thug" comment was the best i've read all night. :D

My car looks almost like the one in my avater, same color and everything , except it has a full body kit: front bumper, rear bumper, side skirts, and the spoiler. but everything in the car is almost just the way my mom bought it back in 85. So it's ALL SHOW, but NO GO. I forgot to mention that my car was a GS. sorry about that. My dad told me that the engine in there right now is the 11b. He also told me that anything higher wasn't gonna fit.
Is this true? and if it is, what kind of engine am I supposed to put in it now? I looked up some sites for rotary engines and didn't find any engines that were 11b. I think I'm in desperate need of help!!!!!! otherwise i guess i'll just get another engine like the one i have in now and try to get other ways to make my car run faster. what a drag. any advice is greatly appreciated!!!!!

There is no 11B ... it's a 12A (or 12B at the most, but we won't get into that :D)

You can put a 13B in it fairly easily, but it's not as easy as streetporting your 12A and putting it back in.

Since you don't know what engine you have, and apparently neither does you dad, pop the hood and start looking. Get a Haynes, or the FSM online, and start learning about your car. If you don't, it can get expensive quick. Especially if you go to a shop and tell them you want your 11b rebuilt. P. T. Barnum would love to see you walk into his shop.

Another good method is to look at the tops of the (rotor?) housings, and look for a cast "12A" or "13B". All show-no go and Occam's Razor implies it's a 12A. Assuming your dad is half-right, and someone swapped in a 13B at some point, he's technically correct as far as an easy engine swap. The usual path is to go turbo with a 13B to get substantially more power. There are probably some 20B (3-rotors) in FBs (nickname for '81-85 RX-7s, based on VIN), but I seriously doubt it's as bolt-in as a 13B turbo. V8 swaps are common as well, but you'd need to go outside this forum for help on that--unless you have rhinohide for skin.

Calm down there, tigress. SS's numbers are pretty eye-popping for a 12A and a dyno sheet is generally called for with unusual numbers like that. Being skeptical and calling someone a liar are two very different things and clean85 was pretty non-aggressive about it.

Directfreak, what are S5 13B or S4 etc...? I mean what dose that mean? lol sorry I am still learning about this stuff.

S5 means series 5 [the model/year of the car], 13B is an engine.
Coz your new to the motor industry stick to a mild port 13B for now.
Once you got the hang of things you go fuely/turbo or whatever turns you on honey
There's also a good chance some fukin monkey is gonna rip you off once he puts 2 and 2 together. Either whip that bitches ass into place or get someone from this msg board to get some decent quotes for you.

Word! :cool:

Trust me, I can understand why you are pulling the BS flag. This 12A is still in break-in. once it is at its full break-in time/mileage.... it will be going to the dyno for tuning with AFR...

As of now I am only running 10deg of total advance... (will go somewhere between 24-27) running through Dual MSD's (I am on stock 1983 Ignition now) and then I can re-jet the Weber.

IN a straight line it will accelerate with circa 1999 Model Camaro SS's When you do the math for my power to weight, based on their power to weight I should be in the range I claimed.

as far as idle goes... Don't take this wrong... (I don't like starting shit flinging contests... and I am not... if you want to call me later and discuss how and why I would be more than happy to educate anyone on the nuances of Rotary engine porting.) I can name off atleast 5 forum member who are local to me who have seen my car, and its idle.... and can attest to its accelerating ability.

BUT... how many engines have you ported? Are you familiar with Laminar Flow? have you ever calculated laminar flow through a rotary engine port based on what you plan to grind it to? Flow through our engine comes in layers if you really take time and port.... you can get much better fuel economy (the TII I just finished is getting around 22 average) and much smoother idle, powerband, etc etc.

I have been on this board for about 6 years... through server crashes etc etc. I don't need to prove anything... IF you come to Rotary Revolution next year.. I guess I can show you anything you want (down the strip and around the road-course too). I'll likely have a couple of my engines on display there anyway.

for future reference... you should have spent alot more time with the primaries, beside just cleaning them up... and you can go alot larger with the secondaries with out any low rpm adverse effects.

the exhaust ports should apear to be chrome...

Well, if you have spent the time to create your motor to get great gas mileage and idle at such a low, smooth rpm, more power to you, brother. I just never heard of such an idle level like that on an RX-7 before; so, I decided to inquire about it. I didn't mean to come off as if I was calling you a liar; it's more along the lines of "is that a typo/how the hell did you do that?" Anything's possible, I know that, and I really would love to see your car. 225rwhp just seemed to be kind of out there for a "streetported" 12A, though; so, I posed the question. Thanks for answering. Maybe you can build my next motor? Heh.

I have an Ad in the upcoming RX-tuner.

Just look for the ad of with the white RX-3 in it. there is also a picture of one of the actual ports in this 12A... (my partner just happened to be taking alot of pictures during that build.)

Bear in mind... I said my 12A was "street-ported" it is more like what the aussies call an extend port..

check out the picture.

the housing is from an engine previous ported by an idiot.... the inner scribe marks illustrate the RB Street-port... the outer one is what I used in the 12A.. you'll note that it has quite a bit more intake duration than the one RB provides.


Back to the subject..
I am still all for a good 12A..... Simple engine change, no big surprizes.. you will not need to learn all the little things needed to convert to say a S5 13B... although it would be a good swap too.

Hehehe, Thanks for the tip Gumby13B and Thanks Directfreak that site was helpful alot.

Your reputation is not being question here. But making such big claims on an untested set up is missleading. Estimated Horsepower. Theres the key.
Oh, and Iam an Aussie and I have an Extended port. Further, power to weight has no place in actual horsepower calculations.
Regards Sue