Engine swap- Whats compatible?
 

Ive been looking everywhere to try and find a interchange / compatibility guide. I Have a rx7 second gen style car (1988). The engine I pulled out of it was trashed and we scrapped it. We have a recently rebuilt gen 2 engine from a wrecked car that had a auto trans in it.

After pulling auto flywheel off of the rebuilt engine, went to bolt the flywheel from the old manual engine on it and noticed it was different on the bolt pattern. The manual flywheel has a notch in the center for a keyway to engage it and four bolts around it, whereas the engine has six bolts around the center bolt and no keyway.

I thought that perhaps the machine shop mixed the flywheels up so i googled it and the flywheel is for the first gen (83 stlye manual flywheel).

So im confused. Im thinking that someone put a gen one engine/trans in the gen 2 car???

In any case I would like to make this work. The manual flywheel is skinnier than the auto, and if I fabricated new holes, the starter would not engage the flywheel...

Are the bell housing bolt patterns the same? Are the clutches the same? Are there changes in the engine from the manual to the auto trans editions?

What do I need to make this work? Will I need a manual transmission from the same year as the engine, or will it only work with the auto??

Does anyone have a list of the different engines and transmissions avail for all use rx7's from say 83- 92?? If I look it up on car-part it seems that there are DOZENS of different styles...

Helppppppp??

Its starting to look like
 

If I get a manual flywheel that has the 6 bolt / no keyway pattern, should it bolt up to the engine, and engage the starter ? And if so will the clutch set that I got engage the transmission, and will the transmission bolt to the engine?

Any pics?

An automatic will have a seperate counter balance that uses the one huge nut to hold it to the e shaft, it has to have a key way, the flexplate bolts to it with 6 bolts. The auto flex plate is bigger in diameter than the manual flywheel by about 8mm.

The manual flywheel will weigh about 30 lbs+or - attaches to the e shaft with the one huge nut and also has a keyway. The engine balance is built into the flywheel.

An aftermarket lighter flywheel will use the automatic counter balance and bolt on with 6 bolts like the flexplate for the auto.

I just figured it out, you are right.
 

I was looking at it and saw that the 6 bolt portion does indeed come off. Once that counter weight is off, the manual flywheel slides right on. However, it is still way much shinnier and wont be engaged by the starter...

Where are you in Florida? I'm in the St Pete area.

The stock manual flywheel will line up with the starter location of the manual trans. The ring gear for the starter will be about 4cm off the back of the engine with either set up.

Ah thanks!
 

Gainesville :icon_tup:

I am putting this thing together for my brother.
 

I am a mechanic with a small shop in gville, this is the first rotory that ive worked on, and know little to nothing about the wankel.

Making progress!
 

So I got the whole flywheel issue. I was confused when I looked at them and noticed the difference. I google images and I saw a whole bunch of the new style light ones that bolt to the counterweight. The only pic I saw of the one that I had went to a 84, but I guess the second gen original flywheels look the same.

I got the new clutch on , and bolted the new engine on, but the enging mounts are about an inch farther forward the the holes that they go in. Cant the trasmission position be adjusted so they will reach or what?

Not a lot of play forward and back at the trans mount, maybe 1/2 inch. I would leave all the trans mount stuff off until it time to lift it up into place.

The engine mounts are a straight through bolt design, make sure there is no offset of the studs coming out of the 'puck'. The studs should line up perfectly. There isn't any way to really have the brackets that hold the mounts on wrong.

I would suspect something wrong with the trans mount if anything.

The trans has never been removed.
 

The trans was in this body when we got it, with a blown engine. The new engine has the mounts on it with 1 bolt coming out the bottom. It sits about an inch forward of where the J shaped hole is.

Take a look at the trans mount, if the trans was hanging in the body it could have pulled on it at some point. Unbolt it from the chassis, line up the engine up front and see what things look like in back.

Since there isn't any way to bend the subframe and mounts up front maybe the part that bolts to the body is bent or the rubber has seperated in the rear mount itself.

2nd gen engines
 

Are the second get engines different lengths like the fisrt gen?
I read that with the first gen engines one style is an inch longer than the other style. 12a /13b or somthing like that. Im trying to see if the second gets are like that too.

13B is a 13B from a second gen(there are early 13B from the 70's but I doubt you have one if there are holes for injectors in it), all the second gen's have 13B's. There are differences in the intake, oil injection system and a bunch of other little things but the engines themselves are the same and will bolt in.