Wrong! No soup for you!

There are kits available online that allow you to use the existing OMP with a reservoir.

http://www.rotaryaviation.com/oil_in...p_adaptors.htm

 

well that would make it more costly. I did not know about those kits wow. But I still would not like the crappy injectors handling what I can do myself.

 

I guess it is difficult to know what is fact and what is fiction when it comes to rotary engines. Almost any change to the system you could mention would generate people both claiming it is the best thing since sliced bagels, and some claiming it is the worth thing you could ever do.
After reading the pre-mix link, I can see that it does have some advantages. But to say the pre-mix distibutes better than the OMP? Well, for one thing I have used pre-mix in engines before- In my weedeater if you just dump pre-mix in and add gas, it does not mix completely unless you shakes the tank (clear tank). So when you first add gas to the tank, you are
hoping the pre-mix distrubutes throughout the tank fairly evenly so that when the fuel enters the engine, it has an apropriate amount of oil with it.
To be honest, this seems whole idea started from racing, since those engines need far better lubrication and shade trees adopted it because it is cheaper than fixing the OMP when it fails or needs maintenance.
Does anybody have any long term experience with premixed engines? How many over 200k rotary engines got their with the OMP, and how many got their with pre-mix?
For the record, I have a 12a which doesn't have fuel injectors. I wonder if this works with a stock carb?

 

I will get some pics up of the rotor housing me and James took off the 88GXL engine soon so you all can see the way it looks in the area where the oil injector sprays the oil and where it does not.

 

You are adding a lot more gas to the tank in a car than in a weed wacker or lawn mower. I would guess it would mix more (makes sense, right?). If you are worried about it not mixing, mix it. Hop in your car, get upto 40, slam on the brakes a few times. Take a few hard corners. It should be mixed in more than enough.

 

Of course I run premix... it's just much much much better for the car.

BTW, this topic has been brought up many-a-time

https://www.rx7club.com/forum/showth...ghlight=premix

https://www.rx7club.com/forum/showth...ghlight=premix

 

I run pre-mix and I recommend it to all rotary engine owners -- absolutely, absolutely, absolutely.

B

 

I agree. However, with premix, we have testimonies from people with extensive experience rebuilding motors that have burned premix. And their posts have been consistent and definite - motors that burn premix (without the OMP) have far less carbon build-up (if any) and the apex seals are in better shape.
I'm not going to hunt these posts down right now - gotta get outta here.

Quote:

But to say the pre-mix distibutes better than the OMP?

Premix does distribute more effectively. There is a substantial difference between the way the OMP injectors and the fuel injectors spray.

Quote:

Well, for one thing I have used pre-mix in engines before- In my weedeater if you just dump pre-mix in and add gas, it does not mix completely unless you shakes the tank (clear tank). So when you first add gas to the tank, you are
hoping the pre-mix distrubutes throughout the tank fairly evenly so that when the fuel enters the engine, it has an apropriate amount of oil with it.

But we're not talking about a weedwacker with a 4L gas tank. We're talking about a car with a 63L gas tank. I don't refuel until after my low fuel light comes on (~11L left in the tank.) Then I dump in premix and gas up - the action of 52+ liters pouring in mixes things quite nicely. And there have been posts stating that members have left premixed gas sitting for up to several months with no signs that it has begun to separate or 'settle.' Again, I'm not going to look for it now, but I will later if you'd like to see them.

Quote:

To be honest, this seems whole idea started from racing, since those engines need far better lubrication and shade trees adopted it because it is cheaper than fixing the OMP when it fails or needs maintenance.

I don't know if it started from racing, but it definitely is a common 'mod' in that community. As for shadetrees, I'm premixing because I want to make life as easy as I can for my motor. The OMP on my car works just fine (the mechanical s4 OMPs *rarely* fail.)




Can't answer this - I don't know offhand what the mileage was on the motors that have been commented on... I'll look tonight - I'd like to see this answered as much as you do.

Quote:

For the record, I have a 12a which doesn't have fuel injectors. I wonder if this works with a stock carb?

Don't know. I don't see how it could hurt anything. Have you posted this question to the 1st gen section?

 

what is a premix?
At first I thought that the premix was using half of the oil motor oil with new but obviously I am wrong but could u guys tell me.

 

Premix oil is oil that is designed to both effectively lubricate the internals of an engine (usually in engines that have no separate lubrication/oil, like two stroke motors in chainsaws, etc) and to burn away cleanly (so that the same motor doesn't clog with left-over residue.

With the rotary, none of the internals contact the engine oil in the pan. So Mazda had a choice - let the customers premix or create a system to pump oil into the engine. Assuming that the public would either be too lazy or forgetful to premix, Mazda chose the latter.

Engine oil isn't meant to be burned at all. It leaves a lot of residue behind in the rotary. Ask 1987RX7GUY to link to those pics he has from when he tore his motor apart. It looks like the inside of a BBQ that's never be cleaned.

 

it says that used with stock OMP about 400:1... I'm running 50:1 right now... oops

 

dude I the most you should use even without the OMP is 100:1 your car must smoke a bit huh?

 

I run 100:1 with no OMP but for the trip to Indy I'll probly run 75:1 *highway's are fun *

 

dang! that suks
what would u guys perfer to do if u think that premix isnt all that great.

 

OK, I am convinced I want (need) to premix. Do I need to remove the any portion of the intake to get to the oil injectors out? Thanks

 

You will have to remove the upper intake manifold to get at the and dynamic chamber to get at all four injectors..... 2 on teh LIM and 2 directly on the housings .

 

you also have to fashion a block off plate and cap off the holes for the injectors.

 

It looked like I would have to remove the intake to get to the oil injectors. At least I can cable tie my silicon tubing when I get in there as I neglected to do so when I retubed under the intake a while back. Thanks again for the reply.

 

Me and my Cosmo are convinced!!!!!!!!!!!! We are gonna go PRE MIXEN! How ya like dat mo fo? I was just in the process of finding a way to run the OMP and now I dont have 2! WooooooooooooHooooooo
Thanx forum peeps

 

I spent the $80.00 for the premix pump and reservoir. I use non-smoking synthetic premix in the oil reservoir. There will always be discoloration where crankcase oil hits the housings by the injectors. I didn't want to take any chances on upper oiling (like having the wife fill up the car and forget the oil). I am not looking forward to rebuilding the engine. Hopefully, I won't have to. It runs strong and idles extremely well and has 94K on it. It will be interesting when I finally do have to tear it down to see how the pump and synthetic oil have worked. If I pass 150K with no major problems, I will consider it a success.
I just hate the thought of dumping oil in my gas tank. I haven't done that since I sold my old Lawn Boy lawn mower years ago. Putting oil in the injection reservoir is a breeze and it's also easy to check. I can see how much of the oil has been used and know that it went to the right place at the right time.

 

Full synthetic with the standard OMP set-up? Yikes! 4-cycle oil going into the combustion chambers is bad enough, but synthetic is even worse.
If you must use synthetic, advise you either ditch the OMP and pre-mix, or install an adapter (block-off plate/ alternate 2-cycle oil feed) between the stock OMP and the OMP mounting surface.

 

Yes you can; and yes, I do. Of course my car is a 12-A (carburated) 1st gen. Metering lines go into the float bowl and mix with fuel there before going into the combustion chambers. One of the "old wives' tales" about this system is the possibility of the gravity-fed reservior system siphoning 2-cycle oil into the intake while the car is parked overnight. (the reservior has to be at least 6 inches above the level of the OMP in order to gravity feed into it). I've seen no such problem with mine. And since the adapter blocks off oil flow from the pan, there's no reason not to use synthetic if you prefer.
Of course, the 13-B uses oil injectors which have been known to fail. I'm wondering if this failure is due to deposits left by 4-cycle oil from the pan (?) If so, then 2-cycle oil should cure this. If not, pre-mix is the way to go.
This adapter is easy to fabricate if you have access to a milling machine. If not, PCV Technologies sells them. E-mail address is unicorn@gdsys.net , phone # is (850) 834-4905. Ask for Richard Sohn. Cost is $76 U.S. for the 12-A adapter, $82 for the 13-B mechanical adapter (which will also work with the GSL-SE 13-B), and $88 for the electric OMP adapter used on the '89 and up 13-B. The reservior, connector hose, and fittings are supplied by you.

 

I premix for 3 reason:
1. My OMP doesn't work well enough
2. Increased Mileage (about 25 more miles on a tank of gas)
3. I like the looks people give me at the gas station.

Chuck

 

so this omp thing, *im really new to the rx7 and fairly new to mechanics* that would be a group of lines going down to by the lower rad hose with a linkage from the throttle to the same spot?

 

yeah