rotoryfan1991

Hey looking into a 13b motor to swap into my rx8, I honestly don't know alot about the differences in 13b motors but am wanting something that I can put a gt35r on and run 18-20 psi on e85 for 500-ish hp. I know the rew is a good motor ( so ive read) however I have found a motor locally that the guy says is built to hold 600 hp easily but has s4 6 port housings and rew rotors/e shaft.. are the s4 N/a 6 port housings a good idea? anyways heres the specs he listed...


For sale is my built 13B rotary engine that I bought for my RX7 project. I, unfortunately, ran out of funding and gave up on the project, so my loss (big loss) can be your huge gain. This engine (with the proper turbo/fuel setup and tune) can easily support over 600 WHP! Also I will be including a stock Turbo II transmission!

Engine specs;

S4 N/A block (N/A engines are 6 port, allowing for more potential airflow than the turbo engines 4 ports)
Rotors and E-shaft came out of a '95 13B-REW (for lower compression than the N/A internals, also they are overall better)
Street ported
2MM apex seals (Rotary Aviation)
Dowel pinned (the block is machined and additional pins are inserted to further strengthen the motor for even more HP/torque)
Custom sheet metal intake manifolds
Custom fuel rails (setup for AN fittings, setup for 6 injectors which will be included, however, I suggest getting new injectors)
104MM throttle body (was actually made for an LT1, this TB is very nicely made)
6 puck clutch (can't remember who makes it)
Stock TII transmission
Aftermarket pulleys (don't know who makes them, they're nice though)
Remanufactured alternator
Polished front cover
Deleted/blocked off OMP and oil injectors (YOU WILL NEED TO RUN 2 STROKE OIL WITH YOUR GAS!!!!)





Would it be a good idea to get this setup or something else? I really want to know the best and safest build for high hp. Thanks for any help!

arghx

iTrader: (3)

There's a bigger risk of cracking an iron with s4 n/a plates. The casting by the dowel pin landing (near the oil filler) is thin.

I know you come from Rx-8's, but you have to realize that there is a BIG difference between a Renesis 4 port and an older turbo 4 port engine. A Renesis 4 port is basically a 6 port engine with the casting for the auxiliaries filled in. The older 4 ports, especially the FD 13B-REW and the Cosmo 13B engine have MUCH bigger ports than the Renesis 4 port engine. There is a tiny minority of guys who like turbo 6 ports (one of the moderators, Aaron Cake) but that is because they want to be different, not because the 6 ports have any real advantage.

Check out some of these pics. Here are some side housing comparisons:



Now the shape of the side housings are different but you can still get an idea of the difference we're talking about here. Here is a comparison of the s4 turbo and Cosmo 13B. The Cosmo 13B has even bigger ports than the FD 13B-REW; it's basically a 20B but with 2 rotors.

arghx

iTrader: (3)

The FD and s5 turbo irons have an additional bracing by the oil filler, as I mentioned. See attached pic. See a thread I made about this a few years ago: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/just-measured-s5-turbo-rear-iron-factory-bracing-pics-795339/ Overall the reinforced irons are around 20% thicker. FD 13B-REW engines and Cosmo 13B engines hardly ever crack irons. That's worth more than any custom intake manifold and throttlebody setup that some guy rigged up.

The mounting on the FC engine is completely different from the FD as well. The REW mounts on the rear iron and the FC engine mounts on the middle iron. The engine mounts actually go through the pan. The crank angle sensor is also better on the FD and does not require adjustment, so you don't have to worry about questionable timing marks blowing up your engine. That's another thing that will make it more reliable. It has a trigger wheel on the pulley like the Renesis. The FC crank angle sensor and drops in like a distributor; if you have the wrong crank pulley on there you will have bad timing marks and you could blow your engine up.

rotoryfan1991

Thank ALOT for the info.

Im gonna pass on the local motor then and just find a good re(w) motor.