I have a 1988 vert I'm putting a motor into.

before it had an S4 TII engine, when I pulled it out it appeared to have an n/a flywheel on it and it has an n/a transmission.


I bought an S5 TII engine to put in (I would've just rebuilt that one - but I needed a turbo too so I just got a used one) but now I'm wondering... what flywheel do I use?

I obviously can't use the S5 TII flywheel, it won't fit inside the n/a bellhousing.

Can I put the N/A flywheel on the S5 engine without swapping front counterweights, or do I need the front counterweight out of the S4 TII engine, or do I need to do something else alltogether?

I really want to get this thing running tomorrow so please let me know if you know the answer!

I searched and checked through the archive but could not find an answer to this.

Perhaps we should turn this into a turbo/na parts interchangeability thread.

 

I don't know for a fact, but with the help of mazdatrix
the S4 and S5 flywheels are different part numbers.

This appears to be due to different counterweights.

 

if your using s5 tII engine you need s5 n/a front counter weight and flywheel if i remember correctly... you cant mix and match s4 and s5

 

well the S4 engine had a (not sure what series) N/a flywheel and an unknown (to me) counterweight... and worked fine, had no vibration or anything.

so obviously an n/a flywheel can be used on a TII engine... but do I need the counterweight off of my S4 engine? Or can just use the flywheel without swapping counterweights?

I pulled the front cover off the S4 engine and it did not appear to have been off before.. (front cover nut was almost impossible to remove, gasket and material looked factory, tons of rust on the pulley) leading me to believe that it has an S4 turbo counterweight. How do I tell them apart? But I'm almost sure it does.

 

s4 tII and s4 n/a flywheels and counterweights can be switched... but you cant put an s4 counterweight and flywheel to the s5 tII or n/a

basically what im trying to say... you cant mix the flywheel and counter weight from the s4 to the s5
only s4TIi to s4 n/a or s5TII to s5n/a

 

so can I put the S4 counterweight on the S5?

or do I need to find an S5 NA counterweight and flywheel?

if I do, does anyone know what the part numbers are?

there's a nonzero chance that I have an S5 NA flywheel, and I definatly have an S5 NA counterweight.

 

Dont we use certain size counterweights because of the weight of the rotors, right? Im not 100% , but I would think s4 counterweights ona s5 engines is not going to work even if you changed both. Im a little new to the rotary stuff.

I dont know your budget, but you can get the correct counterweight for your s5 t2 engine, and go wiht a lightened NA flywheel

Please correct me if im wrong, I would like to know

 

the s5 engine has s5 rotors..which do not work perfectly with the s4 counterweighting. You can't change only 1 counterweight of the 2 on the engine, and even if you wanted to go through all the bullshit of pulling the front cover and swapping the s4 counterweight on, you'd still have the wrong weight rotors and you'd be running the risk of vibration or bearing failure.

Bottom line...find an s5 NA n350 flywheel, bolt it to the s5 turbo block, and go on. You already have the s5 front counterweight on the s5 engine, so leave the front cover alone. Why was this so hard to figure out?

 

I thought that the n/a counterweight may be different from the turbo counterweight. I had an n/a flywheel but I may have thrown it out.

n351. woot.


thanks kevin.

 

FOUND AN N350! WOOT!

 

I know that on my s5 turbo vert I have a na flywheel and a s5 auto tranny counterweight.its a fidanza 8lb.