89_REX7

Sorry if this has been posted b4, i have not found anything in regards to a straight answer about this, I purchased a 1989 Convertible NA obviously with the Series 5 motor in it, the motor was blown due to a corner apex coming undone and tore the rear rotor housing and all up, so i had a Series 4 block manifolds etc everything but the flywheel and transmission, the engine (series 4) has a counterweight attached to it and my series 5 used a weighted flywheel. So my question is "Does the series 4 motor use a counterweight or a weighted flywheel?" I cant personally find a flywheel at all for the series 4, Ive been using this site since i started with my other 89 rx7 and its helped out a lot so i figured id give it a shot and ask the experts. So please any help would be greatly appreciated and any recommendations to finding a flywheel or an alternative would be great.

RotaryRocket88

iTrader: (7)

All automatics have a removable rear counterweight, which is separate from the flexplate. All manuals have an integrated rear counterweight (part of the flywheel).

Since the rear counterweight must match the rotors, you have a couple options:

1) Use the S4 rear counterweight you have along with an aftermarket flywheel. Such as: http://www.racingbeat.com/RX7-1986-1992/Flywheels.html

2) Get some more posts, and buy an S4 manual flywheel from a member.

Red_Rotor

iTrader: (3)

rocket is right. all the autos had a flex plate with a counterweight separate. all the manuals had weighted flywheels. get an s4 manual flywheel cuz the rotors are different weight than the s5. if u have to pull one off an engine in a junk yard, be prepared for a struggle. getting that flywheel nut off is no easy feat. super torqued on there.

89_REX7

thanks i greatly appreciate the info, and response. at the moment i have ACT StreetLite Flywheel http://www.customcarscentral.com/act...mazda-rx7.html and the counterweight to go with it http://www.customcarscentral.com/actcw01-mazda-rx7.html and i also got an unknown staged pressure plate with a 6-puck clutch disk.

cab91089

iTrader: (3)

The link you posted for the ACT flywheel says that is fits a 86-95 turbo model only. I know that they have flywheels for the N/A engines too so hopefully that is what you have. If you have an N/A lightweight flywheel you do not have to take the eccentric shaft nut off or the rear counterweight on the s4 block. Simply bolt up the lightweight flywheel to the rear counterweight on your s4 block. The automatic rear counterweight can/is used as a counterweight for the lightweight flywheels or you can spend the money and buy the same counterweight from a company which is pointless.

RotaryRocket88

iTrader: (7)

^ Yes, hopefully it's an NA version of the ACT flywheel, since turbo flywheels are larger diameter & cannot be used with NA transmissions.

Also, a 6-puck clutch and a super light flywheel will make the car a massive pain to drive on the street. Slipping the clutch gently won't really be an option, so it'll be kind of an all or nothing deal.

89_REX7

Right of course i figured that out after i got the stuff, see the dude i got it from had a N/A motor with the T2 transmission swap and everything, so i didnt even think about it, then once i got home i went to "test fit" the 6 puck on the spline and i knew something was up when the spline for the clutch disk was too big so then later found out i had the turbo flywheel etc blah blah, and now im jus in need of the s4 non turbo flywheel (preferably not a lightweight) but at this point untill i get some $$$ im S.O.L.

89_REX7

well i found a person locally that has i think wat i need, it looks exactly like this http://cgi.ebay.com/ebaymotors/Mazda...item588a8f82f2 so if so ima pick it up 50 bucks , so if so ima go ahead and get it then i should have the car up n runnin by sunday

cab91089

iTrader: (3)

Yes that flywheel in the link is exactly what you need.

89_REX7

now will i need the front counterweight with it too? or will the one already on the motor work ( I'm sure that the motor had the automatic considering that the counterweight on the rear was still on but no flywheel was. So i guess my next question is, do i gotta pull the front counterweight off the motor I'm getting the flywheel off of, or will my existing front counterweight work with the flywheel I'm buying off that guy?

RotaryRocket88

iTrader: (7)

You don't touch the front counterweight. The weights are matched to the rotors, so all you need to do is get the rear one correct.