Mobius

1986 13b non turbo

This is the very first engine I heve ever rebuilt. Never really had much indepth experience with internal piston driven engine parts.

The story goes, my first Rx-7 had a manual transmission. Short strory, coolent seal failure: Engine = toast. (rotor housing warp)

Second Rx-7. This had an automatic tranny. Short story, going up hill one day, my right leg noticing abnormal heat where the tranny is housed. Tranny make big crack noise, Transmission then was functional in 1st 2nd and reverse only = toast. That's kinda ok, I hate automatics.

Now currently, I am combining the two. Good engine with good manual transmission in the best body (the Automatic body is good)

What I want to know is, does anyone out there who is more experienced have any suggestions, comments, concerns that I should address before the final re-instalation?

What I have done so far:

New oil seal springs and o-rings on rotor oil seals. Oil seals not replaced because they are ok.

New apex seals, side seals rubber buttons and all parts related,

Full Rotor Housing inspections

Full Rotor inspections

Full rear front and intermediate housing inspections

New rotor bearings.

New main bearings

All new, and full gasket replacements. Oil pan, water pump, water pump housing, lower intake throtle body, actuators, metering oil pump etc.

New oil pump chain.

New oil injector lines.

New exhaust header (Racing beat)

New exhuast (Racing beat)

New bearings related to eccentric shaft endplay (haven't checked actual endplay yet)

New fuel injectors by RC engineering

New air intake from K&N

New thermostat, and O2 sensor.

A few modifications:

Omitted the check ball and spring and used webber 200 caborator jets placed inside of the oil jets on eccentric shaft. They are conically shapped.

Ommited oil thermal unit which turns on oil jets in eccentric shaft. Oil jets are always on regardless of temperature.

Any suggestions? like what weight of oil I should use to brake it in? ECU different for a manual tranny than an automatic? Tranny mountings different? Car body mountings differ from manual to automatic? Counterweight issues? Coolent line issues? More modifications? ANYTHING, even minor that you think might help would be appreciated! The last thing I need is to terd-launch the 3,500 I've spent so far.

Thanks'

Mobius drive.

HWO

here's a suggestion: DITCH THE OMP AND PREMIX IT!!!!!!!

NathanRX7

What do you mean the automatic body is better? They're all the same for each series (86-88 and 89-91). The automatic uses a different counterweight than the manual, so make sure you get that worked out, and I don't think the ECU is different, but I'm not sure on that. Good luck.

4rxz

i have an automatic
i was reading about converting to manual and someone that did the conv. said the auto tranny is longer and the crossmember of the tranny is 8 inches backer than manual not sure but try a search on auto to manual transmition

i will like to know if it matches up or not

NathanRX7

Oh. I think I understand what you're saying now. The actual bodies are no different though. You can put either tranny in either car, but you will also need the driveshaft and differential, maybe also the halfshafts.

HWO

weather they are manual or auto they all have the same differential and half shafts

its just the box, drive shaft and mount which is different

NathanRX7

The auto differential has 3.9s, and the manual has 4.1s unless it's a GTUs which has 4.3s.

Ryde _Or_Die

Or TII

NathanRX7

T2 has 4.3? Can anyone verify this? I was looking at http://beyondtheredline.fd3s.net/Spr...gen2.html#1990 and is says all are 4.1 except the "GTUs".

HWO

T2's all have 4.1:1

i forgot about it being a non turbo car originally

ReZ311

iTrader: (4)

what's wrong with an OMP? I don't trust the premix method for various reasons.

Good luck on the rebuild. =)

4rxz

might help
http://home.rmci.net/panther/trans.htm

HWO

at least with pre mix you know its actually getting oil into it, with the OMP its sheer good faith that the thing is actually working

the benefits of premix by far out way the little trouble you may have of remembering to put some oil in everytime you fill up with gas

Mobius

Greetings nathanrx7

thanks for the reply.


RE:.
The automatics body is in better condition that that of the manuals'.

The counter weight issues are most puzzling. Since I have torn down each engine I examined both. When I compared the front counter weight from the manual, to the automatic's, the automatic had a deeper bore located on its bottem end. Also, the rotors differed ever so slightly. There were different lightly shaved bores at the top of each apex. I am sure you have seen them here and there. I thought these bores were uniform for all rotors, but appearently that's not so. The bores differ in depth and quantity. I assume that the bores are counterweight related. Should I use the manual's front counterweight? Or the Automatic's, when I am sing the automatic's rotors and eccentric shaft?


Mobius drive

Mobius

Hello Hwo,

thanks for your suggestion.

RE:

However, I am a bit of a novice with the slang. I don't even know what FC stands for. As you can imagine omp is a little rough.

Mobius drive.

Mobius

Greetings 4rxz

Thanks for your reply.

RE:

Lucky for you I have been documenting all of this with a digital camera.
As soon as I am done and everything works correctly, I will put it on the web. Probably mid Febuary.

Do you have anything you want digitally specified while I'm at it?

Mobius drive

Mobius

Oh and......


What would the effect be if the diff is not swapped? Seems like the list keeps getting bigger and bigger.

Mobius drive.

NathanRX7

Are all of the cars in the same series of 2nd Gen (FC), as in are they all 1986-88 (Series 4), or all 1989-91(Series 5), and are they all non-turbo? The difference you are seeing in the rotors is not because of the different transmissions, but could be different compression ratios. The Series 5 non-turbo FCs (2nd Gen) have a higher compression ratio than the Series 4 non-turbo FCs. If you leave an automatic differential in the rear, which has 3.9 gears, it will result in slower acceleration, slower off the line, but a higher top speed, if the motor has enough torque to get it there. If you use the manual differential with 4.1 gears, you will have the proper acceleration, etc. If you are lucky, you can get hold of a "GTUs" differential which has 4.3 gears. It is also possible to buy other gear ratios and rebuild the differential you have with different gears. There's at least one guy on the forum that has 5.12s.

4rxz

just the tranny conv, thanks

Mobius

Hello

RE:

Each of the cars are 86 non turbo. I have a pretty good idea about the history of the manual as I bought it from a friend. The automatic on the other hand was a tow away that I bought from a mazda shop who sold it because it was abandoned with them as a rusult of a bill.

The auto is an interesting one. First thing is that the hood is much lighter. It came with a straight pipe exhuast, and the transmission cover, interior wise, was never there so it never locked in place in the sense of pushing the thumb button on the shifter (slightly dangerous)Its major problem was that the fuel injector seals where cracked and when driven it was like driving a molitov cocktail. For all I know it was originally a manual transmission. Also, it was really sluggish off the line even when the fuel injection was re-sealed. If someone wanted to race you'd literally have to time the takeoff just right. I think my moms little four cylinder corrola could beat it off the line.

But like I said, why would the front counterweight, located where the oil pump chain is, have a deeper bore?