Rusty Shackleford

I have a 85' GS but the engine (12a) has blown an apex so im replacing my engine with a 80' (12a) that im getting for a good deal...it comes with everything that was on it when it was pulled from the car except the clutch disc and starter.

So....i have been looking around for a new clutch setup for it because i was told that the clutch on my engine now wouldnt work on it....but after looking around it seems like its pretty hard to find a clutch kit for a good price for an 80'...whats the deal with that??

Why cant i find somthing like this???? http://cgi.ebay.com/ebaymotors/XTD-S...65864083QQrdZ1

Thats what i was going to buy just as my engine went out. And my starter is less then a month old which now i think i need to swap over also........

COULD I USE A CLUTCH FROM AN 83-85 besides the size which is a 10mm difference what makes it so you cant use the same clutch??

gearhead-42

You could switch out the whole clutch and flywheel <I think that's all>... but the old (85) clutch pressure plate won't bolt to the new (80) flywheel...

85rotarypower

The 80 uses the same clutch disk and pressure plate as the 81 and 82's I think, which is a 215mm diameter. Not really hard to find at all. Your local speed shop should be able to get any centerforce clutch kit, or a stock clutch. Either that or go to mazdatrix or Black Dragon Automotive.

Rx-7Doctor

iTrader: (13)

Just use your clutch setup including your flywheel from your 85.

evita

My 84 SE has an early 12a with the 215 mm clutch. I bought a ACT Stage II clutch from a local speed shop for $325.00 with tax (8.25% in Texas). Clutch works great, now with about 20,000 hard miles (street/roadcourse).

You can get a stock clutch for about $150 from any local autoparts.

dj55b

iTrader: (2)

I bought that ebay clutch looks good ... but haven't installed it yet so can't put back anything one that.

Siraniko

iTrader: (13)

I can get them 215mm clutches @ action clutch in east los angeles. Let me know what type you want and how it will be used/application.

trochoid

iTrader: (6)

I thought the flywheels and balance weight are different and changing them is a nono. Other option is to go with a lightweight flywheel and couterweight for your year, then use the 225 mm clutch and pp. Might run 6-700 by the time you're done though.

Best bet might be to go through Wacky or check your local parts store 1st for an oem one.

Rusty Shackleford

so if i just swap over my flywheel from my 85' onto this 80' engine i will be able to use my clutch and PP that i have now without any problems?? The flywheel will just align right up??

trochoid

iTrader: (6)

The early/215 mm units and the late/225 mm units have different flywheel weights, along with the rotors. The rotating system will not be balanced if parts are mixed. This will cause vibrations internally and wear the bearings prematurely. How long for damage to occur, no idea. I know some of the ITA/IT7 guys have run the mixed combination and have not reported any short term issues.

The choice is your's. While you may save money in the short term, and get a better clutch, long term wear may require replacing all 4 bearings for the next rebuild and possibly the e-shaft if wear is excessive.

broke7

iTrader: (1)

pm me and i can setup you up with a used 215mm centerforce for a cheap price

dblclutch

iTrader: (1)

I think early flywheel and counter weight is lighter than the later but the later rotors are lighter than early ones.

When the lighter parts are used together and balanced with the clutch and pp , you have less rotating mass therefore a little bit faster car.

85rotarypower

DO NOT SWITCH THE FLYWHEELS!!! The 85 flywheel is weighted differently than the 80 flywheel and it will trash the bearings in your motor. The 12A rotors up till 82 were 10.15 lbs while the 83-85 rotors were 9.6 lbs. Always match rotors with the flywheel. E-Shaft has little bearing on this as they are balanced from the factory. Here is a pic of what the bearing from a 88 engine with 10.05 lb rotors looked like with an 83-85 flywheel meant for 9.6 lb rotors.



Hopefully you can see it, but the copper is showing on the bearing half way around it. Once the copper shows, the bearing is garbage. The engine this bearing came out of had some real bad chatter marks and scraping on the rotor housing as well. Another note, this engine only had 60K KM on it, thats about 35K miles.

Siraniko

iTrader: (13)

I disagree. You can mismatch with no noticeable issues. I have done it except this is on S3 12-A motor with 21lbs flywheel from 81-82.

rotornoob

iTrader: (2)

holy shnit buttman!!

i didn't realize that a late model gen 1 flywheel/clutch/pp swap could to that to an early 1st gen....good to know....

and what a pretty mirror finish that copper has =P

85rotarypower

That was a rear stationary gear out of a "good" engine I bought for $700. The whole engine pretty much ended up being scrap. The front stationary gear was the same.

What is the weight of the RX-3 12A rotors? I'd be willing to bet they are pretty much the same as the 79-82 RX-7 12A rotors, which would explain your observation.

Siraniko

iTrader: (13)

83-85 stock 12-A motor with 81-82 21lbs flywheel. not just once but twice. That was the set-up when I first purchased the banana RX-3 as it was in ITA. My bro used it in his SA for a few years before I took the engine apart and streetported. But the OC line blew and seized the motor. I replaced it with a free 83-85 12-A motor, ditched the heavy flywheel and replaced it with the lighter 81-82 flywheel. So far, over 20K miles on that set-up.

defakto

I thought if you went with a different fly wheel you also had to replace the counterweights to keep everything in balance and if you did that you should have no problems.

rotary_83

I bought a EXEDY oem replacment for my 12a for 120$ shipped. It was throw out bearing, pilot bearing, pressure plate, and clutch disc..And yes it's stamped EXEDY and not a knock off, and it is brand new...Really detrochoid pm'd you

rotary_83

lol. Forgot to finish a sentence, I went off and did something and came back and hit send before I read it, oh well...I meant to say that it depends on your need. Do you need it out of the garage or on the track to last? My car is an 82 GSL and I had no problem with finding that clutch kit, just have to search.

trochoid pm'd you

trochoid

iTrader: (6)

Didn't recieve one.

Rusty Shackleford

so thats a no go on putting the 85 12a flywheel onto the 80 12a???

I was looking at MAZDATRIX at clutchs and it said it was fine to mis-match...

RX3SP

iTrader: (62)

I've run the same setup...81-82 12a flywheel on a 83-85 12a engine for well over 100k miles with no noticeable adverse effects.

Rusty Shackleford

i looked at my flywheel and by the mazdatrix photos for flywheels it looks like the right one thats on the engine now......but the surface is 225mm and the clutch disc that was being used is 225mm even though this is a 1980 engine with the 1980 flywheel????? Am i measuring wrong??


I dont feel like starting a new thread but.......

Can i just take some high grit sand paper to the flywheel to knock the rust off of it??? i did on one little spot and its shiney under neath all the rust and dosnt have any pitting....is this ok to do or should i take it off and get it resurfaced by a shop??

trochoid

iTrader: (6)

If the flywheel has no pitting, burn marks or gauling, sanding is fine. Some light marks can be sanded out with 220 grit paper, heavier marks need machining.