Ok, here is one that has me stumped.

I have a '85 GSL-SE 13b and the CenterForce light weight steel flywheel. Says to install the automatic counter weight from my engine model/year.
Well there was no automatic '84-'85 13b cars produced.

Anybody has a acurate answer for this one?

Thanks,

 

I'm not 100% sure but I believe you can use the counter-weight from the 86-88 cars.

 

yea, it should work. same rotor weight, same compression ratio (on NA)

 

Well according to MazdaTrix the 86-88 rotor weight lighter than the 84-85 13B.


13B 84-85
compression: 9.4
Wt. Grams: 5253
Wt. Lbs: 11.58

13B N/T 86-88
compression: 9.4
Wt: grams: 4553
Wt. Lbs: 10.04

although the Rx-4 rotors were the same weight the flywheel was a lot heavier, so the would mean the front counterweight would be bigger too.

13B 74-78
compression: 9.2
Wt. grams: 5253
Wt. Lbs: 11.58


John

 

John,
I just picked up a light flywheel from a GSL-SE for myself, and the casting number on the counter weight is 1029A.

I hope that is helpful ~ JEB

 

JEB, actually after reading your post, it got me thinking.

I pulled out my old Rotary Engineering catalog and for counter weights it list:
'74- '85 13B .........1029-11-751A


BINGO, its a match, now I need to find a Automatic Rx-4 counter weight.


thanks
John

 

Isnt it great how this works