Re-Rotorising RX-2 - Technical thread

Kaptainbalistik · February 23, 2006, 09:48:53 PM

Has your car got the straight front crossmember or the horseshoe front cross member?
If it is the straight crossmember, The RX7 sump fits nicely (It better, Im using one!) If Its the Horseshoe, Twin dizzy sump time! (Reversed sump to RX7) I know someone in Oz who has a few (He does/Did build my motors)

Modify the rx3 engine mount crossmember to fit the rx2 (Gives more exhaust space, I think jap performance in Oz sells them cheap,there pretty good with that stuff), However, the RX7 front mount bracket thingy plate is short by about 2 and a bit inches. Easy to "adjust" with 6mm steel plate and a gusset or 2.

The motor will be in the correct position when the oil filler pipe is in line with the Shock tower strutt bolts.

The Rx7 gearshifter is in the right spot when you cut the gearstick housing and the shaft so the rear bolts are in the front mount holes. (about 3" shorter) You will need to redo the gearbox crossmember.

Also, you want a 929 stationwagon tailshaft (Thats if you can find one!) , Unless you want to run the car low (Or silly suspension travel), Then you need the 2 piece shaft.

If you need any more help, just yell. (Ive gone through this all before)

Martiny · February 24, 2006, 07:40:19 AM

The cross member is the horseshoe shape, or banana shape. I have read that its possible to just turn the RX-7 sump around and drill some extra hole in it for the bolts? Maybe this affects the pick-up, though?

I will now have to get that 7 engine out of the shed, and start having a look, so I know what I am talking about !

Kaptainbalistik, I remember we spoke at the Autosolo, and I now know what you meant about the crossmembers that go under the anti-roll bar mounts. I think thats better if installing a 13b. For me, I think fabricating mounts onto the horseshoe crossmember is a better idea.

Are you coming to the FDMC Autosolo in March?

Martiny · February 24, 2006, 07:41:20 AM

Gearbox out, engine is ready to come out. I have borrowed an A frame and pulley system, thanks Andrew ( Jinx)

Kaptainbalistik · February 24, 2006, 09:39:36 PM

Yep , Im busted! ( Peter\'s the name by the way)
Is that the Borough 19 sprint? (Hope to, Need to find some old rims and tyres and get some neg camber pins, Oh and change the clutch!)

Has the crossmember still got the mounts on it? If so, you may be able to use a set of cosmo engine mounts. (Thats if the motor has the side mount stud holes ). If not, I would go for front engine mount. (Mines a 12A and it is a simple job to fit the motor.)

You can redrill the sump and reverse it (there is a leak issue though) or I think you can use a rx4 sump . The twin dissy oil pickup is about 20 cm long and bent so it runs close to the bottom of the motor.

If you are not worried about originality, Moving the motor back makes a big difference to the handling on a RX2.

Also, You will need to dimple (Actually, quite a big bash in) the firewall/tunnel to clear the clutch lever on the top of the motor. (The heater is right behind , but it can be made to clear neatly) This is nessisary when the motor is in the original spot too as the twin dizzy clutch lever is where the starter motor is on a RX7.

Finally if the car has always been a manual, you will have to tap in the tunnel on the passenger side to clear the starter.

As far as I remember, The RX7 radiator can fit.

Martiny · February 25, 2006, 07:12:32 AM

Quote from: KaptainbalistikYep , Im busted! ( Peter\'s the name by the way)
Is that the Borough 19 sprint? (Hope to, Need to find some old rims and tyres and get some neg camber pins, Oh and change the clutch!)

Has the crossmember still got the mounts on it? If so, you may be able to use a set of cosmo engine mounts. (Thats if the motor has the side mount stud holes ). If not, I would go for front engine mount. (Mines a 12A and it is a simple job to fit the motor.)

You can redrill the sump and reverse it (there is a leak issue though) or I think you can use a rx4 sump . The twin dissy oil pickup is about 20 cm long and bent so it runs close to the bottom of the motor.

If you are not worried about originality, Moving the motor back makes a big difference to the handling on a RX2.

Also, You will need to dimple (Actually, quite a big bash in) the firewall/tunnel to clear the clutch lever on the top of the motor. (The heater is right behind , but it can be made to clear neatly) This is nessisary when the motor is in the original spot too as the twin dizzy clutch lever is where the starter motor is on a RX7.

Finally if the car has always been a manual, you will have to tap in the tunnel on the passenger side to clear the starter.

As far as I remember, The RX7 radiator can fit.

Yeah March 19th. Check it out on the FDMC website.

Ok, I know about the clutch and the starter issue, so I will have to bend the tunnel a little and grind down that clutch lever.

Engine mounts from which Cosmo? This still mean I have to tap and drill a thread i the engine to tak a side mount , right? Then I have to find an RX-2 side mount that goes on the engine!

I think its easier foer me to try and weld need mounting points on the cross-member to take the front mount style.

Was thinking about what you said about the bearing in the prop shaft. Unlikely I will change the ride height. So I think I do actually need the bearing, as it rides so high! There is quite an angle on it. Maybe Era, and Dave have never had a problem because all their cars have been lowered, so the shaft would run "straighter" I think.

The shaft that came off has a bearing, so I will try and use that one.

Martiny · March 05, 2006, 08:12:05 PM

Ford engine is now removed. Now I took the "good" engine out of the shed. It turns over fine, and it feels like its got compression. I might connect the gearbox and starter, and do a compression test before I fit everything, what do you think?

I now notice that the front pulley has been removed :-( I have another engine, so I can just take the pulley off that, but there was a thread on here a little while ago, with a link to Mazdatrix, about the needle roller bearings falling out of place if the pulley is removed.

Will I have to remove the front cover now to re-align the bearings and fit the pulley?

Its a 1983 12A

Martiny · March 07, 2006, 07:07:10 AM

http://www.mazdatrix.com/faq/pulley.htm

ah found it.

Damn, front cover has to come off.:-(
Ah well, I think I need to remove the sump anyway.

Kaptainbalistik · March 08, 2006, 01:39:46 PM

HB Cosmo motor brackets to be precise! (Ill still go the front mounts!)

Martiny · March 08, 2006, 03:24:56 PM

Ok, what are the implications for my oil pickup if I turn the sump around?

Kaptainbalistik · March 08, 2006, 09:16:27 PM

you need to extend it so it sits in the middle of the sump bowl.

If you can mig weld (or tig) its just a pain.

You need a piece of tube the same Dia and thickness as the original about 30cm long.

Stainless would be good if you can weld well.

Hacksaw cuts into the pipe so you can bend it into a tight bend (A la jap titanium exhaust style! Works very well ) and make a new pickup pipe, and weld the old ends back on

Or use a RX4 pickup.

You may also have to dimple the sump to give enough clearance for the 1st pickup bend.

The factory manual has some good pics, (Mine\'s in a shipping container in Aust , sorry!)

Actually, Its got pics of the mounts as well!

PS take the thrust plate off as well because the end float spacer can jam in the back thrust bearing when the pulley is removed. Also , check the Endfloat because the new pulley will Affect it. (You probably knew that!)

Martiny · March 09, 2006, 07:45:49 AM

Thanks for all the help. I didnt realise the new pulley would affect the float, thanks for that.

Right, calling Carl / Dave Nixon, - does ayone have an RX-4 oil pickup please?

I can MIG, but not all that well. I s\'pose I could get a pro shop to do it if I found the bits.

Martiny · March 10, 2006, 08:18:15 PM

Next problem looming.

The plate that goes under the gearbox, to mount it, has a big step, as if the RH side mounts much higher than the LH side.

However, where the body holds the gearbox mount is even on both sides, so I cant use the standard RX-7 mounting. I guess it wont be difficult to make one.

multirotor · March 10, 2006, 09:11:48 PM

I have put a 79 Rx-7 transmission with an 85 12a into my Rx-2. Original driveshaft, original shifter position, engine forward about an inch.
New crossmember from a 1974 Rx-2 (but an Rx-3 one would work just as nice).
Let me know if I can help. I do have some pictures.

Kaptainbalistik · March 10, 2006, 09:46:03 PM

Series 1 RX7 box... Damm I forgot that one!

I used a 2-3 mm wall 1.5" box tube for the rear mount, cut so it wedges between the chassis rails. Just put 3mm bearer plates in the footwells (Harness mount size). Use about 3mm of washers to space the gearbox up to the right height.

I also use a pair of bolts on each side, to stop the crossmember bolts coming undone.

Ray · March 11, 2006, 09:12:48 AM

Martin,

If you\'re wanting to to mount the engine back further than standard, but still keep the standard shifter position, you could use a gearbox extension housing from a 626 or Mazda 2000, I know I\'ve just got one! The stick is about another 3 inches further forward than a series 1, so pushing it 6/7 inches further forward than your series 2 box. The attachment shows it pretty clearly.

Ray