Ok, I'm putting an se 13b into my 84 gs, which already has the gsl se suspension swap. Anyhow, I'm going carbed,(Dellorto 48) so can I still use the oil injectors and just plug the nipples on the back? I'm eliminating all the emissions crap in advance, but it would be nice not to have to re-route the omp lines into the uim. Also, just curious, but is there any difference between the gsl se tranny and the 12a? I have both, but the 12a is already in and is still good.

 

yes use the stock omp line location. the gear ratios between the two r different, the se having a taller 5th, but otherwise the one already in the car will work just fine.

 

sorry to hear you aren't using the EGI on the 13B. such a smooth setup. the transmissions are different but will interchange. the SE trans had a double vented bellhousing and a taller 5th gear ratio in addition to a 5th gear switch.

 

Well, this being my DD, I don't have the luxury of a learning curve for the EGI. I do still have a 280z that was fuel injected that will eventually be getting a 13b as well, I'll probably use that as my testing ground since I'll have to be re-doing wiring and everything else while I'm at it. Plus, then if I'm having trouble, I still have the FB to drive. Not to mention I already have the Dellorto 48 and uim, so I only needed the injector block offs to do the swap.

So if I'm understanding this right, I can just leave the omp and oil injectors as they are and they will still function? Even without the vac or whatever lines were attached to the rear of them? Can I just use vac caps on em? If thr 13b tranny has a taller gear, I'll probably go ahead and use it then. I don't have a hoist or any concrete or driveway, so I have to do everything with a come along on a beam in the covered gravel carport. So I was considering leaving the 12a tranny in just to make things easier on me.

 

the 12A trans will work fine with the 13B from a GSL-SE. in fact, my 85 GS that i converted to EGI with an SE engine still has the original 12A trans behind the engine. i originally used a GSL-SE trans but the bearings were too worn so i took a leap and used the original trans from the car and found it to be perfect.

 

Well, for now I'll just go with the 12a tranny in the car and can always swap in the other later.

On the oil injectors, I'm told that they HAVE to have vaccuum to work properly, so can I just run a line from my intake to the four way and connect them up? Some of the "spider" hoes were cracked or hard, so I pulled it all before realising what it was for. LOL

 

No vacuum. I have the same set up in my Cosmo. GSLSE engine with RB Dellorto. I just have the hoses connected to a t which is open to the outside air. Stock connection is to the plenum where outside air pressure is available.

 

Cool, so you ARE running the OMP and not premixing right. And you are using the stock oil injectors with the nipples on rear "T"ed and open to the air and everything is working as it should? Sorry if this seems redundant, but I really don't want to go through all this and install my motor only to have it lock up because I didn't do the omp and oilers correctly. What do the "nipples" on the oilers do if they just vent to outside air? I just figured they were a vac actuated diaghram or something that opened at a vac signal.

 

There are little diaphragms in the oil injectors that give you a little squirt of oil when the vacuum changes - kinda like an accelerator pump would. Every time you alternate between high and low vacuum, you get a little extra oil, particularly if you're shifting from WOT. They can be run without any vacuum and you'll just get the steady flow from the OMP.

If you want, you can just plug the holes in your housings, swap your 12A front cover onto the SE engine and take advantage of the old OMP, and just run 2 lines to the float bowls. Either way, you'll be fine.

 

No pre mix, but my dell has nipples for the other two omp lines also. I have all 4 hooked up. I can see the oil running through the tubes. FSM has a simple test for the oil injectors. Air should flow through the injectors when you blow into the air nipple. Air should not flow when you suck on the nipple. Section 2, page 7.

 

Thanks guys! I really appreciate the info. I'm running the stock se lim with mods, so keeping the factory oil injectors will simplify things. I just wanted to be damned sure I was doing things right before I got it installed and found out by toasting the motor. I'll go ahead and test the injectors via fsm instruction, just to be sure they are functioning properly though.

74RX4- what is the jetting on your Dell? I bought a rebuild kit to do mine and a few jets etc. to tune with, but it was originally on a 12a street port and not quite tuned said the PO. Will be rebuilding tonight.

 

Iirc, the line to the injectors is filtered fresh air, not vacuum. As intake vacuum increases, this may allow more oil to be pulled in. If it was a vacuum line, oil would be sucked back into the line.

 

Ok, so I never get much sleep anyway and I'm sitting here last night thinking about oil injectors .......... Seems to me that the SE oil injection and OMP setup is a better more efficient setup than the 12a setup. Since the SE front cover will bolt onto the 12a, Would a guy be nuts to put an SE front cover and omp on a sp 12a and tap the intake for the oil injectors, running one injector per port? Seems that would be a nice upgrade to a well built 12a. Of course this is assuming the 12a has an aftermarket intake and carb. Thoughts?

 

there's really no reason/benefit to running more than one omp line per rotor.

 

So oiling the seals/rotor from each side is no more efficient? Does oiling the 2 intake runners or mixing in the carb really lubricate that well? Sorry if this sounds stupid, but it would seem like oiling from the port on either side of each rotor would lube better than either mixing into the fuel or oiling the main runners. I am obviously no expert on this, so I could be way out in left field, which is why I come here to ask. My secondary question would be, if there isn't a benefit, why did Mazda go to the four line omp's from the two line ones to begin with? Is that another of the emissions type compensations made for the motor?
Thanks.

 

Well Mazda has taken a hit over engine oiling in the RX-8 because it's housing-only metering. It's been found that the oil doesn't spread across the housing very well and you get localized wear. Back in the day, they mixed it in the float bowls, everything got metered evenly, and it worked great.

With the GSL-SE and later 7s they had one direct-oiling port in the housing, and the ports in the runner would allow for some pooling and spreading of the oil in the runners and atomized with the fuel charge. What they lost was the ability to mix it in the float bowls.

As long as you're running the Dellorto, I'd recommend a 12A cover, 2 lines, and plumb them into your float bowl for good distribution. The king of all long-lived rotaries is the 3mm-sealed family of the 74-85 12A and 13B.

 

Thanks Crit. I knew there had to be a reason, even if it wasn't a good one. I'd think Mazda's R&D woulda figured that out and went back to the 12a style. But that's why I don't make the big bucks. LOL!
BTW- Running the 12a now with IDF, but dropping in the SE 13b with a Dellorto soon as I get it cleaned up and sorted out. Was just curious as I have other 12a's as well.