Premix Ratio??
 

If you are going to do a premix, what' the ratio? Do you just use the usual engine oil? Yes I did do a search.

Thanks!!!

Ray

Tcw3 rated 2 stroke oil @ 1oz per gallon.

I usually do 1 oz. per gallon plus a little more since I have a turbo and it can't hurt. I use Valvoline multi-purpose TCW3 since I can buy it by the gallon.

The only thing I can add to this entry is that the 2 stroke oil used is for a water cooled engine. I've only used the walmart generic TCW3 2 stroke oil for marine outbourd engines and it seems to work great and it's cheap. It does'nt leave any burnt oil smell. Going on four years on full BP 13b and running strong!

Here you go Ray. It's always better to get the answer straight from the source. http://www.idemitsu-usa.com/page_210.htm

This all I use. I love me some Idemitsu!!!!!!!!
Some testimonials for ya http://www.idemitsu-usa.com/page_200.htm

I use the Amsoil Saber professional 2-stroke. Fully synthetic. Run at a 100:1 ratio.... approx .5oz per gallon....

uh ho, he said the " S" word.

I use just over 1 OZ per gallon. You can hear a clear difference in the way the car runs when you do less. Mazda does 1:150 IIRC at WOT and I'm mixing 1:128. Doesn't hurt to be safe. When I fill-up I put in half a quart so I'm closer to 1:100. When the car is low on fuel you can clearly hear a difference in the note emitted from the exhaust. It's much raspier at the end of the tank which is leaner mixture due to the settling of the oil at the bottom of the tank, at night for example, and the imperfect mixing procedure. You cant shake the tank every morning. I use Idemitsu now. I used to grab what ever was available. Chevron, Valvoline, etc. as I could never tell a difference, but with the Idemitsu there is an audible difference in the way the car sounds it's so much smoother and so much less raspy running their premix. Another thing to consider is Idemitsu's premix was developed as a supplement to the MOP, not as a replacement, so the 1/2oz per gallon they recommend is in addition to a stock working MOP.

"Provides additional lubrication for apex and side seals to increase seal life and increase efficiency of engine."


Check your Math .5 oz per gallon is 1:248...

I just started using idemitsu also for my T2 motor, by builder said 1oz per gallon seems like exhaust dosent smell as much now

pot... kettle... black!! I forgot to carry the one... :rolleyes: 1:256

Amsoil Saber 8oz per fill up is what I use and what my builder (Dave at KDR--a Mazda rotary master certified mechanic) recommends. He actually recommends a little less but 8oz for racing conditions.

Thanks guys for the quick and helpful responses, sounds like between 0.5 and 1 oz/gallon is what to use. I'm curious, that seems like more than the OMP delivers. Is adding the oil through the carb via the OMP more efficient somehow than adding it as a premix?

Also what's the difference between using engine oil, as the OMP does, and 2 cycle oil? Is 2 cycle oil designed for premixing and is therefore more stable than engine oil would be when mixed with gas?

2 cycle oil is design to be combustible so it doesn't leave the carbon that regular
engine oil would leave.

Ray, your premixing? Has the OMP gone south on the silver one?

Exactly what he said. Gasoline is oil based, so any oil should mix fine. However, regular oil is not designed to burn--it is designed to protect and while it will burn, the additives in it are not intended for that resulting in carbon build up.

Oil designed for premix is intended to burn. Some people use Home Depot brand and claim that works perfect. Others use Lucas (premix, not regular) or whatever they have available. Everyone has their preference. I have had success with Lucas (burns clean), but I usually use Amsoil as they generally make good products. To each his own.

Premix and gas MD, but they have different densities and if the car is parked all night some will settle to the bottom of the tank. Put gas and premix in a Mayo jar. Let it sit on the counter for a while and tell me what you see. Pre mix will burn better than 4 stroke. Plus you're not burning contaminants from the sump when you switch to premix. The best solution is running a MOP that draws premix from a resivoir and mixes it in the carb. Then you dont get the settling in the tank issue. That's why I run more. I suggest anyone try 1oz per talon and pay close attention to the tone of the engine. I can almost gaurentee below 1/4 tank it makes a completly different sound than it did full. Its because there almost no premix left and you're getting seal chatter.

Some of the Aussies use caster oil and say it Burns sweeter. Old racers swore by it. Check out the premix threads on ausrotary.com

@ Hyper, I will experiment a bit and see if I can tell a difference in the sound... Good advice...

Reminds of RC airplane engines. You used a fuel that was mix of castor oil and
alchohol (if memory serves me right) and it smelled good. Those were small 2 stroke
engines too.

Hyper, I'm not sure if you are fuel injected or not. However, the issue you describe may be possible with carb fuel pumps. I have owned RX-7s from all generations, all fuel injected and all premixed and I have never had this issue. Fuel injected systems pull in much more fuel than what is needed--especially high performance pumps. Unused fuel is redurned to the fuel tank at around 40psi. This causes a constant mixing of the tank and its contents.

Prior to startup, I let the Bosh 44 complete its prime, fuel is at least stirred at that point, and then I start the car. The pump constantly running and the natural sloshing of the car movements have always kept my fuel well mixed.

I have never owned a carbed engine and I am not familiar with the amount of pressure that they run at so it may be a concern with carb fuel pressures.

Some interesting points about mixing, that could be a problem with my low pressure pump for the Nikki. Sounds like hooking the OMP to a reservoir is the best solution, I'll look into that. Of course you would need to get used to keeping the reservoir filled.

Yes Tim, there is a problem with the OMP in the Silver One. I went to check the OMP output yesterday because I was suspicious about not getting the usual puff of smoke on start up and discovered there was no output at all.

So I wanted to quick get some premix in the tank until I get the OMP problem figured out, which is why I stuck this post up.

I added 16 oz 2 cycle oil to the 15 gallon fill up this morning. Rotaries sure do run better with a little oil in the gas.

https://www.rx7club.com/1st-gen-archive-71/oil-12a-mop-mod-illustrated-597431/


https://www.rx7club.com/1st-gen-archive-71/oil-oil-metering-options-550951/


https://www.rx7club.com/1st-gen-archive-71/oil-omg-omp-519139/

its not the pressure, but that it recirculates. any car with a return line will circulate the fuel around enough.

so i agree, any STOCK rx7 should be fine

Well I'm carbed, and I do run a recirculated fuel system, but it's not recirculating shit when it sits in the garage for a day or two. I guess every time I start my car I could let the fuel pump run for a few seconds before I start it.

I didn't know that, now I know I have not done any premixing I really need to do that then. I guess I will have to go buy some soon. :icon_tup:

I'm liking the premixing too, I get a lot less smoke than I did when the OMP was working. I guess because of what was said above, the 2 cycle oil is meant to be burned and burns cleaner than the engine oil. Although I must confess that puff of blue smoke in the morning was at least some assurance that I was getting oil into the rotors.

And I'm still curious about this settling problem when you premix, I'm going to do Hyper's bench test when I get some more oil, see if it really does settle out overnight. Other than possible settling and the extra expense I could get used to this premixing.

And I'm still wondering why my OMP isn't putting out. The lever is operating and the tubes are filling, but when you disconnect them and run the engine not even a drop dribbles out. I've switched OMPs with the same result (3 different ones), so it doesn't seem to be the pump itself.

Is it possible for the drive to the pump to stop working?

Thanks for the clues on this guys!

What rpm do you measure it at? Could be at idle its just not able to pump it
well. I think the FSM has you measure it at a specified rpm but I don't remember
it off the top o my head.