i have a s5t2 engine an and 87 with s4na of course. the s4 most likely has a blown coolant seal. so i was thinking rather than rebuild it or go through the hassle of trying to make the s5t2 work, why not tear them down and make a good high compression NA. i came up with this. i'll need to find the rotors though.

s5t2 rotor housings
s4na side plates
s5na rotors
s4na intake manifold/intake
s4na exhaust header
s5t2 tranny,clutch,flywheel and starter

any input would greatly. lots of input please.

 

Seems like youd be going through a lot of work to have roughly the same performance you have now.
With the S5 rotors, you'll also need the front counterweight and an S5 flywheel.
To make the Turbo trans work with the NA differential, you need a custom drive shaft or swap the entire Turbo rear end.
Also, the S4 NA ECU and intake doesnt really allow you to make much power past 7k, so the S5 rotors aren't worth it, imo.
If your happy with how your car performs now, Rebuild the S4 motor and sell the S5 TII engine for extra cash to spend on suspention, good tires, ect.

 

Just port the **** out of the s5 turbo engine and run it NA. You'd make more power than using anything s4. Ther are a few vids of guys running just straight turbo engines na and ripping some serious ***. Lower compression and you can run some pretty aggressive timing.

 

Run the whole TII engine with 9.7 rotors.

Trust me, you'll like it. The 4-port side housings work a lot better than the 6-port ones, and any 6 port intake manifold is going to be crap because of how it has to be shaped. I'm a convert!


4-ports are sporting car engines. 6-ports were made to haul around luxury cars mated to automatic transmissions.

Personally I'd use the N/A drivetrain parts, mainly because I've heard the T2 stuff doesn't like shifting at high RPM. Turbo engines were low RPM gruntmotors, after all. (Luxury-car engine, again) I am also a bit biased because I play with 1st-gens and it is really expensive to put a T2 transmission in one because of the driveshaft situation, but I really don't have any problems.

 

Im not really sure whats going on here with the posts above. I think you need to get real. Find another n/a engine from an S4 car, put it in your car. Have a car you can drive while you save up $ to buy an S5 shell to drop your S5 engine in. Be smart. Save yourself the hastle. Leave the engine alone.

 

if i rebuilt the s4na with s5na rotors it would be pointless then?

 

basically... its would be better to run the s5 t2 engine in there

 

It would not be worthless, it actually would be a pretty nasty little motor. The only thing I would change is get the s4 T2 center iron because they do not have the egr passage so there is more room to port (the bolts are still there for the emissions stuff to bolt on so if you need to pass a visual emissions inspection...
Basically yes it would be worth it but I would run s5 na rotors and e-shaft, s4 T2 center iron, your s5 T2 front/rear iron and housings. Then sell all the rest of your parts to fund your build. If you street port it you can make some pretty nice power and still get pretty good fuel economy (in rotary world), be daily drivable and pretty reliable (compared to a T2 which is just higher maintenance). Plus since it is NA you wont have the low end torque of a t2 so it will be nicer to your divetrain (if driven correctly).
Just my opinion.

 

87baserx-7
can't use a s5 center iron? i was thinking of a street port when i'm done. and i'm not worried about emissions.

 

or s5tii e-shaft?

 

sounds like a lot of useless work

 

The s5 t2 center housing has the egr passage right next to the ports so you just don't have as much room to play as in a s4 t2 housing
And its not that much more work then any other rebuild/port? Ohh yeah also you will want to use your t2 intake (it will match your 4-port setup and you should at least port them a bit for the best gains) mated to your s4 throttle body (for the tps so you can use the s4 ecu because it is nice and stupid, ie easy to fool into running just about anything na)
Also I don't think there is anything wrong with the s5 t2 e shaft but your flywheel would have to be from a turbo car so it would be a different clutch. just if you are going through the trouble to get the s5 na rotors i would not use the s4 e shaft because it just shouldn't be reved as high
Is this s5 t2 you have supposed to be a complete good engine? if it is then you might want to consider the swap because it really wouldn't be all that bad and if it is assembled and doesn't need a rebuild then it would be cheaper.

 

4-port kick the *** of 6-port. Less wall surface to port area, less port area for a given amount of timing (that means VELOCITY). If you're using stock manifolds, TII manifold flows better than N/A.

Do how I did... get a complete N/A rotating assembly, a complete set of TII housings, add seals as necessary, and have a lot of fun.

AFAIK the E-shafts are essentially fully interchangable so there's no benefit one way or the other.

The PROBLEM you may have is why did the TII blow a coolant seal, meaning, did it crack the seal land out of one of the housings? (This is how I got my running N/A core engine)

 

actually the NA is the one with possible blown coolant seal. it fills the overflow with coolant in like 10 minutes.

as for the tii. i bought it off of jdm.com. i purchased a s4, but they didn't have one so they gave the s5 for the same price. that's before i knew about the different series. i've never actually gotten to run it so i'm not sure if it's good. it's the full motor with tranny and ecu/harness. the ******* ecu is crunched though and the intercooler is bent. i'll put some pics on my profile so you can see.

 

well besides that

 

$100 bucks says future fs thread.