[quote name='psyclo' date='Jul 20 2005, 10:03 PM']In my non-fact-based-reasonable-logic-only opinion that a mix of 1oz:1gal would be good for a car being broken in or that is getting tired to help seal and give a couple psi better compression. For a fresh sealed healthy motor 1oz:2gal should be just fine (based on the experience that my car hasn't blow up yet)


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well premix is not really used for sealing or compression, its used to lubricate the parts of the motor that doesnt get sufficent oil or any at all, such as the apex seals, rotor housings, corner seals, outer diameters of the side housings ... etc.

Yes I know what premix is used for. https://www.nopistons.com/forums/pub...IR#>/smile.png but there is a reason a motor has lower compression when it is flooded. The oil is flushed off the seals and walls of the rotor housings. If you think about it logicaly it makes sence, dry seals dont seal quite as well as lubed seals.

Its the same in pistons engines, if a motor has been sitting for a while or is very flooded many times they add some oil to the compression chamber to help build compression back up by helping the seals seal.

Just on a side note. Do you guys see much exhaust smoke with using premix? I see alittle under acceleration. This could be my tuning though, still running rich.

OK here goes; first newbie question.

Why premix? Doesnt the engine automatically lubricate and/or premix fuel/oil ? Wont this F up the cats? Or is this a secret way to extra engine life?

Because the stock system burns engine oil in(lotsa carbon and other crap in it)

Yes it does, however the system is designed for conveniance over best performance.

No it shouldnt, when you pre-mix you use 2-cycle TCW-3 oil that is meant to burn. By my logic if it doesn't screw the cats by burning oil thats not meant to burn it wont screw them up with oil that is.

This is a "better" way of lubrecating the apex and side seals than the stock method (useing some decent reasoning without actual tests). However it also has been seen by engine builders to reduce the amout of carbon build up inside the motor.

Thanks for the reply psyclo.

Should I now premix oil/gas?

What is the best and or easiest method?

You don't have to, your motor will not break with the stock Oil Metering Pump system (OMP). If you want to pre-mix, most people remove the OMP to clean things up in the engine bay and stop the injection of engine oil into the combustion chamber. You can then run synthetic motor oil without worry of wheather it will burn properly.

If you pre-mix I have found good luck with having a measuring cup in the car that reads to about 5oz and a long neck funnel, one that will fit into the gas hole without spilling. I usualy figure out about how much gas I'm going to put in, measure the appropriate amount of oil (somewhere between 1oz:1gal - 1oz:2gal like said earlier) and dump it in, then fill up with gas. My thinking behind putting the oil in first is that hopefully it will mix better with the gas than if I put the oil in last.



Be sure to get at least a TCW-3 2-stroke oil, more expensive stuff will probably protect better but use at least a TCW-3 oil. I tend to look for ones that explicitly say meant for fuel injection, just to be sure it wont clog the injectors 10k miles from now.

Once again, psyclo, thanks for your time and knowledge. https://www.nopistons.com/forums/pub...1047683894.gif

Castrol Outboard motor oil tcw3, 10ml's to 1 liter

Past issue of Bass &Walleye boats (like our rotary mag) they showed independent lab results on the oils. Belive it or not the Penzoil walmart had the best protection with the best additive package when it was finger printed.

The major motor brands werent close. Who would have thought?

Cheapest too....except the TWC3 100% Synth.