Fitting new motors to old RX's
01-31-06, 05:19 PM
#26
Junior Member
Join Date: Jan 2006
Location: Sacramento, CA
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Crit
83 and up had electronic ignition on the single dizzy, and 84-85 use a cleaner installation with the ignitors mounted to the side of the dizzy rather than in a separate box, like earlier units.
This place:
http://www.wankel.net/~krwright/cars...stributor.html
Indicates the '81+ was electronic - can you elaborate on the differences between '81-'82 and '83+?
Thank you... (again
)
01-31-06, 06:48 PM
#27
No distributor? No thanks
Thread Starter
iTrader: (6)
Join Date: Oct 2003
Location: Outskirts of Road Atlanta
Posts: 3,438
Likes: 0
Received 6 Likes
on
4 Posts
S2 cars (81-83.5) are electronic with a remote unit for the ignitors. S3 cars (83.5 - 85) have the ingnitors on the distributor and use it as a heat sink, so there's no need for a remote layout with its own heatsink. It's just a lot cleaner, plus the ignitors (J-109) are more plentiful.
And yes, front covers are almost universally interchangable. There are 4 MAJOR varieties - 68-73 (dual dizzy front-mount), 74-85 (single dizzy front mount), 86-91 (single dizzy, [CAS, really] side mount) and 93+, with a pair of inductive pickups on the pulley and no dizzy provision at all. To clear up the ignition problems, a simple S2 or S3 electronic RX-7 setup would be the easiest way to go.
And yes, front covers are almost universally interchangable. There are 4 MAJOR varieties - 68-73 (dual dizzy front-mount), 74-85 (single dizzy front mount), 86-91 (single dizzy, [CAS, really] side mount) and 93+, with a pair of inductive pickups on the pulley and no dizzy provision at all. To clear up the ignition problems, a simple S2 or S3 electronic RX-7 setup would be the easiest way to go.
Last edited by Crit; 01-31-06 at 06:52 PM.
01-31-06, 07:03 PM
#28
Junior Member
Join Date: Jan 2006
Location: Sacramento, CA
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
Thank you so much for that concise reply - that information is so hard to come by on the net.
I'll go see what motor I've got at home, and I know the distributor I've got separately would be an S2.... If nothing else, the front cover I've got gets me started, then it's just finding the right distributor.
Fantastic. Thanks again!
I'll go see what motor I've got at home, and I know the distributor I've got separately would be an S2.... If nothing else, the front cover I've got gets me started, then it's just finding the right distributor.
Fantastic. Thanks again!
01-31-06, 07:09 PM
#29
Originally Posted by Crit
S2 cars (81-83.5) are electronic with a remote unit for the ignitors. S3 cars (83.5 - 85) have the ingnitors on the distributor and use it as a heat sink, so there's no need for a remote layout with its own heatsink. It's just a lot cleaner, plus the ignitors (J-109) are more plentiful.
And yes, front covers are almost universally interchangable. There are 4 MAJOR varieties - 68-73 (dual dizzy front-mount), 74-85 (single dizzy front mount), 86-91 (single dizzy, [CAS, really] side mount) and 93+, with a pair of inductive pickups on the pulley and no dizzy provision at all. To clear up the ignition problems, a simple S2 or S3 electronic RX-7 setup would be the easiest way to go.
And yes, front covers are almost universally interchangable. There are 4 MAJOR varieties - 68-73 (dual dizzy front-mount), 74-85 (single dizzy front mount), 86-91 (single dizzy, [CAS, really] side mount) and 93+, with a pair of inductive pickups on the pulley and no dizzy provision at all. To clear up the ignition problems, a simple S2 or S3 electronic RX-7 setup would be the easiest way to go.
1980 are electronic but the igniters are NOT in the distributor. They are in a separate box and from what I read (but I cant confirm it) the signals are reversed. (green and red wires)
81-85 are the same. Again, I read that lthough there is a slight variance between the SE and non-SE. HOWEVER, it didnt notice any difference when I switched back & fort between SE and NON-SE dizzy.
02-01-06, 11:38 AM
#32
Senior Member
iTrader: (4)
Join Date: Apr 2004
Location: Charleston, SC
Posts: 340
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Crit
S2 cars (81-83.5) are electronic with a remote unit for the ignitors. S3 cars (83.5 - 85) have the ingnitors on the distributor and use it as a heat sink, so there's no need for a remote layout with its own heatsink. It's just a lot cleaner, plus the ignitors (J-109) are more plentiful.
And yes, front covers are almost universally interchangable. There are 4 MAJOR varieties - 68-73 (dual dizzy front-mount), 74-85 (single dizzy front mount), 86-91 (single dizzy, [CAS, really] side mount) and 93+, with a pair of inductive pickups on the pulley and no dizzy provision at all. To clear up the ignition problems, a simple S2 or S3 electronic RX-7 setup would be the easiest way to go.
And yes, front covers are almost universally interchangable. There are 4 MAJOR varieties - 68-73 (dual dizzy front-mount), 74-85 (single dizzy front mount), 86-91 (single dizzy, [CAS, really] side mount) and 93+, with a pair of inductive pickups on the pulley and no dizzy provision at all. To clear up the ignition problems, a simple S2 or S3 electronic RX-7 setup would be the easiest way to go.
I guess I better save the front cover off one of my bad motors.
02-01-06, 02:05 PM
#34
Senior Member
iTrader: (4)
Join Date: Apr 2004
Location: Charleston, SC
Posts: 340
Likes: 0
Received 0 Likes
on
0 Posts
What I was thinking, get a later 13B engine (side mount type) and use a 12A front cover, of which I have an extra. That way, I can use the custom front mount I made to put a 12A in my rotary Spitfire.
Or, is that necessary? (I don't have a later 13B to eyeball at the moment.)
Or, is that necessary? (I don't have a later 13B to eyeball at the moment.)
02-01-06, 02:28 PM
#38
Weird, your tranny mount lines right up. I have an 85 12a in my 72 RX3 and I used the RX3 motor mount, but the tranny mount didnt line up with my 79 smooth case tranny. I had to use flat metal to make a "bracket". Mounting my engine this way left plenty of room for an electric fan, and I used the stock RX3 radiator. I used the 12a oil pan from the 85 engine as well. It all just dropped in. I only had to change the tranny mount to get it to work. I used the starter from the 85 engine too, since the top mount starter wouldnt work anymore.
02-01-06, 02:43 PM
#39
Rotary Power !
iTrader: (1)
Join Date: Mar 2002
Location: Belgium, Europe
Posts: 534
Likes: 0
Received 0 Likes
on
0 Posts
My pictures are from my Rx-2, not my Rx-3.
As you can see the Rx-2 tranny mount was slightly modified (holes slotted).
Since that was not enough, I also inversed the 79 rubber tranny mounting block. That block is not 100% vertical so I did win about half an inch there too.
Did you use the original Rx-3 driveshaft ?
Is the shifter position the same as before ?
As you can see the Rx-2 tranny mount was slightly modified (holes slotted).
Since that was not enough, I also inversed the 79 rubber tranny mounting block. That block is not 100% vertical so I did win about half an inch there too.
Did you use the original Rx-3 driveshaft ?
Is the shifter position the same as before ?
Last edited by multirotor; 02-01-06 at 02:46 PM.
02-01-06, 03:00 PM
#40
Senior Member
Join Date: Jun 2004
Location: SoCal
Posts: 598
Likes: 0
Received 0 Likes
on
0 Posts
On my rx3 I used the T2 transmission and shorten the tail end 4". This way I didnt have to move the motor forward and the shifter is not too close to parking brake. still left me plenty of room in the front for my elecric fan. But I had to fab a new braket for the transmission.
02-01-06, 04:20 PM
#42
Originally Posted by islandsnow
On my rx3 I used the T2 transmission and shorten the tail end 4". This way I didnt have to move the motor forward and the shifter is not too close to parking brake. still left me plenty of room in the front for my elecric fan. But I had to fab a new braket for the transmission.
02-01-06, 05:19 PM
#44
Senior Member
Join Date: Jun 2004
Location: SoCal
Posts: 598
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Jesuscookies
Can you explain how you "shortened the tail end" or point me to a link on how this is done? I read the "how to" On cutting the shifter rod, and was completely confused.
https://www.rx7club.com/old-school-other-rotary-63/t2-trany-rx3-479612/
02-02-06, 08:44 AM
#46
Originally Posted by P-nut
multirotor has the engine pushed foward and islandnow has it in the stock locatoin.I think stock location is better and less work.
Stock tranny
Notching the front engine mount bracket wil keep the shifter in the original location. If you decide not to notch it, then the engine will move back and tranny mod is required.
81+
Shifter is further back so you will need to modify the shifter hole again and mod tranny mount. To keep it in stock location, then mod the remote shifter as the above posts.
If you dont slot the front bracket, then the engine will move about an inch back. Pay attention in the clutch slave/fork as it may get too close to the firewall and tranny mods are required. In addition, the shifter will get close to the handbrake. With the handbrake, you can mod a 626 handbrake (remove about 2 inches from the middle, re-welded back and shortened the handbrake release rod).
Again, a RX-2 is a different ball game than a RX-3 due to cramp engine bay. For N/A application, moving the engine back is NOT necessary but for turbo, its a must to make room for E-fan/radiator/IC.
I hate long post.
02-02-06, 09:41 AM
#47
Originally Posted by multirotor
My pictures are from my Rx-2, not my Rx-3.
As you can see the Rx-2 tranny mount was slightly modified (holes slotted).
Since that was not enough, I also inversed the 79 rubber tranny mounting block. That block is not 100% vertical so I did win about half an inch there too.
Did you use the original Rx-3 driveshaft ?
Is the shifter position the same as before ?
As you can see the Rx-2 tranny mount was slightly modified (holes slotted).
Since that was not enough, I also inversed the 79 rubber tranny mounting block. That block is not 100% vertical so I did win about half an inch there too.
Did you use the original Rx-3 driveshaft ?
Is the shifter position the same as before ?
02-02-06, 10:22 AM
#48
Senior Member
Join Date: Jun 2004
Location: SoCal
Posts: 598
Likes: 0
Received 0 Likes
on
0 Posts
heres what needed to be done to shorten the t2 tail end.
Measure the bolt holes, It is much easier to measure from one end to the other when measuring center hole to center hole ( but you already know it's 4"). Youll need to remove the shifter collar off the shifter shaft, to do this you'll need to remove the access hole on the other side of the housing and align dowel pin towards it, that's the only way it will come out. The third picture shows I shorten the housing and the tube by 4". You then need to move the dowell pin location extactly 4" forward and shorten shaft. Try not to damage the rubber gromett when removing it off the tube you'll need it and make sure the trany is in nuetral when taking the tail end off.
The last picture will give you an idea what exactly needed to be done. Now get to work....
Measure the bolt holes, It is much easier to measure from one end to the other when measuring center hole to center hole ( but you already know it's 4"). Youll need to remove the shifter collar off the shifter shaft, to do this you'll need to remove the access hole on the other side of the housing and align dowel pin towards it, that's the only way it will come out. The third picture shows I shorten the housing and the tube by 4". You then need to move the dowell pin location extactly 4" forward and shorten shaft. Try not to damage the rubber gromett when removing it off the tube you'll need it and make sure the trany is in nuetral when taking the tail end off.
The last picture will give you an idea what exactly needed to be done. Now get to work....
02-02-06, 12:22 PM
#50
Originally Posted by islandsnow
heres what needed to be done to shorten the t2 tail end.
Measure the bolt holes, It is much easier to measure from one end to the other when measuring center hole to center hole ( but you already know it's 4"). Youll need to remove the shifter collar off the shifter shaft, to do this you'll need to remove the access hole on the other side of the housing and align dowel pin towards it, that's the only way it will come out. The third picture shows I shorten the housing and the tube by 4". You then need to move the dowell pin location extactly 4" forward and shorten shaft. Try not to damage the rubber gromett when removing it off the tube you'll need it and make sure the trany is in nuetral when taking the tail end off.
The last picture will give you an idea what exactly needed to be done. Now get to work....
Measure the bolt holes, It is much easier to measure from one end to the other when measuring center hole to center hole ( but you already know it's 4"). Youll need to remove the shifter collar off the shifter shaft, to do this you'll need to remove the access hole on the other side of the housing and align dowel pin towards it, that's the only way it will come out. The third picture shows I shorten the housing and the tube by 4". You then need to move the dowell pin location extactly 4" forward and shorten shaft. Try not to damage the rubber gromett when removing it off the tube you'll need it and make sure the trany is in nuetral when taking the tail end off.
The last picture will give you an idea what exactly needed to be done. Now get to work....