juantii

Hello!
I want to use 87-88 Turbo II 8.5-1 Compression rotors with an old 13-B 75-78 eccentric shaft with the same old style front counterweight and a 87-88 Stock Turbo II flywheel or an aluminum lightweight flywheel for the same Turbo II with the corresponding rear counterweight.
The questions are:
1)Is this rotating assembly correctly balanced to rev up to 8,000-9,000rpms?
2)If it is not balanced what will I have to do to get it right?
The Street Ported 13-B will be turbocharged in the 25-30psi of boost range.
any info will be greatly appreciated.
thanks!

Aaron Cake

iTrader: (1)

You will be fine as long as you have the matching counterweight and flywheel for your rotors. If you go to a lightweight flywheel, you'll want to use the automatic counterweight.

juantii

so you think it doesn't matter that I will be using the old 13-B eccentric(Not the Turbo II eccentric)?
ok this is really great for me because I had this 8.5 Turbo rotors for some time now but I had my doubts if it was possible to do it with the old 13-B eccentric and old 13-B front counterweight.
I will go with the stock TURBOII flywheel for the moment and assemble the engine.
thank you for your help!!

FelixIsGod29X

iTrader: (50)

To use those turbo rotors you need the front counterweight from the t2 assembly and the t2 flywheel, not your old 75-78 13b front counter weight.

juantii

Will do so....thanks!

lastphaseofthis

iTrader: (8)

some one should tell him that old shaft is junk, and an rx-8 shaft will work, and be lighter, and can be had pretty cheaply.
US $229.95
NEW-EBAY

juantii

Does the type of shaft use affect the balance of the rotating assembly? If the RX-8 shaft is lighter isn't this going to affect the balance of it.

FelixIsGod29X

iTrader: (50)

Pftt the rx8 shaft is probably overkill for you. Just use any regular second gen e-shaft. I got a shaft that came out of a s4 t2 i would sell fairly cheap.

FelixIsGod29X

iTrader: (50)

Werent rx8 eshafts like $100 for the longest time? Now its more thsn double? No thanks

j9fd3s

iTrader: (3)

nah the old one is better, no thermal pellet!

juantii

from the advice that I have received here I will have to use the front S4 TII Counterweight, 8.5 TII Rotors and Stock S4 TII Flywheel but I'm not sure now if I can use the Old 13B e-shaft?

RotaryEvolution

iTrader: (30)

you can use the old shaft but IMO the treating processes were inferior in anything pre 1984.

i honestly can't even tell that those old engines had nitrited irons, that is how badly they were done and the old shafts i can tell don't have the same tensile stringth due to the heat treating process and more squared off edges.

2nd gen shafts are a dime a dozen.

for those of you who say RX8 shaft, get a clue. the standard 1986-1995 13B shaft can handle 1000+ crank horsepower easily. a few ounces of weight isn't going to spin the engine noticably better.

juantii

I don't have a 2nd gen shaft but I have an FD RX-7 REW 13-B e-shaft that I can use if its better. So it doesn't matter what e-shaft(old or new) I use it won't throw the balance off as long as I use the corresponding TII front counterweight, rotors and flywheel and if I go lightweight flywheel use the automatic corresponding counterweight. I'm ready now to assemble the 13-B I'll let you know how it goes.
thanks everyone for your help.