gradedcheese

I finally obtained a manual gearbox for my RX-2 sedan (from ebay). I also bought the manual-version starter (top mount) from the guy and he was nice enough to pull the flywheel for me as well. The gearbox is out of a '72 RX-2 so it should just bolt up.

Once it stops raining I think it will be time to pull out the automatic, pull the flywheel, install the manual flywheel, and then the gearbox. Hopefully after that my RX-2 will finally be useable.

I saw a couple pages on the net about automatic->manual conversions on RX-2 and now I can't find them. Can anyone post links?

I now have those parts plus the pedals and the gearbox should is complete down to the shifter so after getting the hydraulic parts and a clutch kit I should be set.

Anyhow, this is very exciting

multirotor

iTrader: (1)

Won't it hurt engine balance to just change the flywheel ? Normally you should change the front counter weight too.

Jeff20B

iTrader: (13)

How often is that actually true, multirotor?

It should be fine, cheese. I have the engine and tranny from an RX-2 and I know exactly what you're talking about. Looking at the front counterweight, it looks like any '74-'79 (or '80), other than some cross-hatch cuts on the outer edge. I'd assume it is the same for auto and manual, but '73 and older stuff is different in other ways, so I'm not 100% sure.

gradedcheese

ah, interesting! I never thought about a front counterweight as well as the flywheel one. Anyone know additional stuff about this? My car is in fact a '73 and I've never had another Mazda to compare to.

I guess I'm looking at pulling the motor anyway, but I think I'll stay with the twin distributor ignition for now unless I get really ambitious so I wasn't planning on much in the front of the motor, unless I find a header and remove and block the air injection, etc.

Right now I figure on:
- pulling the motor and automatic
- installing the manual pedals and setting up the clutch master
- chopping the cooler lines off the radiator (I don't like this Mazda radiator, I'll try to get something different later)
- bypassing the neutral safety (plus other?) wiring
- swapping flywheels, installing the gearbox and a clutch kit, swapping starters, putting on a clutch slave, and then reinstalling the motor and installing the clutch hydraulics

I can't remember if there were issues about crossmembers or any other mounts and related things. Hopefully that's not an issue, but I'm looking around to see if it is.

Looks like Mazda used the same (or close enough) console for both auto and manual cars so I can just install he shifter in the stock one and not worry about it.

Jeff20B

iTrader: (13)

You can still do simultaneous firing of both leading plugs with points. I agree that you should leave the twin distributers in the engine.

gradedcheese

cool I'm examining the gearbox I bought, it's pretty clean and complete but wow what a weird design. There are two things that have two wires coming off them (one is the reverse light switch, the other I can't even guess as to what it's for).

This thing looks way overengineered and funky, it's probably larger and has more parts than the 12A motor. Flywheel looks very usable, I'll just need a new clutch disc and a slave cylinder. I also need thatrubber "dust boot" for the shifter.

For the ignition I think I want to either leave it alone or run a MSD 6A (or two) to talk to the coils. Points don't bother me much.

Jeff20B

iTrader: (13)

If you do that, the points will last forever.

I think the other thing with the wires was some sort of anti-start switch incase the shifter wasn't in neutral when trying to start the engine.

gradedcheese

ah, wow. So I guess I'll just figure out which one is the reverse switch and hook it up to the car's wiring now and then just short the nautral safety thing. It has one of those now (whcih doesn't quiet work because it won't start in "park") but I don't need it.

Looks like I have the complete assembly including the little dust boot. Hopefully the crossmember and other moutning will just swap over from the automatic.

I'm going to try and get an MSD box for it on ebay. Do you think Just hooking up one box would be sufficient? I've seen a lot of setups with two boxes but I don't see why one couldin't just directly fire the ignition.

Jeff20B

iTrader: (13)

Here is how to use an MSD box on the leading dizzy. Don't waste your money on trailing.

Just buy yourself an MSD 6A or 6AL and hook its points sensing wire to the leading dizzy's points output wire (the one that goes to the negative terminal on the stock coil). Get yourself an FC leading coil or some other DIS style coil. Hook the orange and black wires from the MSD to the new coil, and hook both high tension outputs of the DIS coil to both leading plugs. Make sure the MSD has a good ground and power source for its thick black and red wires. Lastly, don't forget to hook up the thin red wire from the MSD to your key switch. I think that's it; you'll have one naked dizzy cap. Both leading plugs would fire at the same time like stock '86 and later RX-7s.

You can also accomplish this with a Chrysler ignition module. I think the GM HEI ignitor modules can also be triggered by points, but I'm not completely sure.

gradedcheese

Ah, thanks, that's interesting. So essentially the trailing distributor would be unused? Would there be any advantage from somehow also firing the trailing plugs?

Jeff20B

iTrader: (13)

The trailing distributor would remain stock. I guess you could get an MSD for it, but it would have to run through the cap and rotor, and trailing doesn't really do anything for power. In my opinion, it's not worth spending any money on; especially if you're going to buy an MSD for leading.

now

iTrader: (1)

If i remember right ( its been 15 years or more since i worked on a rx2)
you have to change the rear iron housing to use the top starter on an auto engine.

matt

Jeff20B

iTrader: (13)

You are correct, now. Hey Graded, have you looked at the top of your rear 'plate' yet? Have you seen the top of the manual tranny's bellhousing? There is a cutout in both halves on manual cars.

gradedcheese

ah crap. why do they make this such a pain? I can make an automatic BMW into a stick in about four hours Gaaaah.

Well I'm up in San Francisco for the holiday but as soon as I come back I'll take a look. So basically what you guys are saying is that I have to pull the 12A apart and change the rear housing to a top-mount-starter-manual housing which I can only get off a pre-74 rotary?

As much as I like this car I'm thinking maybe I should cut my losses and sell it to someone who has more parts and money and will be able to finish fixing it up

now

iTrader: (1)

I cant remember now but i think you could use a rx3
4 speed your auto starter and the auto drive shaft
this way you don't have to open the motor.
or was it the bell housing off the auto with a rx2 trani.
I remember putting a auto engine into a manual car
but i cant remember all the parts i used to do it.
I know i used the auto drive shaft.
then had to pound like crap to get the lower starter to
fit in the manual top starter car.
this was over 20 years ago, getting old is a bitc#

matt

now

iTrader: (1)

did i see in another post that you said that your auto
had a top mount starter? if so just bolt up the manual
and your good to go. but i thought all the autos had lower starters.

matt

gradedcheese

I do have a top-mount starter motor with a top-mount starter automatic right now. I bought a RX-2 4-speed gearbox along with the starter (top mount). So I should be ok then? Thanks for the info either way!

now

iTrader: (1)

o ya you will need the drive shaft to, the auto one is shorter

matt

gradedcheese

oh crap

Jeff20B

iTrader: (13)

I'd imagine the auto tranny is the same length as '74 to '85 manuals. That means it'll be 40mm longer than the RX-2 4 speed. You'll need to double check that it truely is 40mm before messing with your driveshadft. Just pull out the auto and set it by the stick. That's the the easiest way to tell.