I did some research, but I want to clarify before I dump oil in my gas tank. My oil level has never dropped in the whole year I've owned the car. I've never had to add oil at every refuel. I'm under the assumption that the OMP is either weak or inactive. Would adding 8 oz. of wal mart 2 stroke (super tech?) be about right? wal mart seems to be the popular choice. im also going to switch to 87 octaine. would diluting the gas with oil decrease the octaine too much or would it be ok?

How long would the engine be safe with a bad OMP?

Should I be worried about passing emissions. I have to pass in May.

Car is an 86 GXL.

 

Adding 2 stroke to gas will lower the octane a little, but not noticable. I ussualy mix my oil 100:1 or so. i dont see it being a big deal to be exact. I buy good 2 stroke mix myself, a 16oz bottle will normally do me for 2-3 fillups. So I guess 1oz oil per gallon would be plenty. Engine will be safe for as long as you add premix every tank of gas. As far as emissions i dont know, i dont have to pass any, so ive never tried.

 

People always say it will lower the gas octane rating but I've never seen any numbers to prove that?



I'm running 1 ounce oil to 1 gallon of gas which I think is 120:1. I have the OMP disabled/blocked off and bolts in the injector holes. I usually get the gallon jug from Walmart of Penzoil 2stroke and pre-fill bottles for fill ups.



I'm not to sure if it will pass emmisions, but I have heard of people passing with it on this forum.

 

actually that just triggerefd something. Correct me if Im wrong, but higher the octane number the slower the fuel burns. Im assuming the oil burns slower than the fuel, so in actuality, wouldnt it up the octane rating? Though the way its rated it wouldnt really do much of anything to the number. i mainly just assumed it slows the fuels burn down, as it probably isnt as explosive as gasoline.

 

actually its more like a resistance to combustion......like if you can't run 87 on high *** compression....you need 91 so that it doesn't detonate. the octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites.

and also i don't think that using two stroke oil will lower the octane rating specifically because of what it is. two stroke oil was designed to not only lubricate but mix with gas and be burned in a combustion chamber. not positive though.

 

oh yeah and i dunno why wal mart 2 cycle oil would be a popular choice. i run a mobil 1 synthetic 2 stroke oil. i have my omp blocked off and i also run amsoil pure synthetic in my oil pan. you see because the omp injects oil from your pan into the intake when you block it off you will be able to run synthetic whereas with the omp you would be injecting synthetic in and rotaries don't like that. it causes excessive carbon buildup.

synthetic in the tank and in the pan.......its a win win situation.

 

well my thought behind it was the fact that surely 2 stroke doesnt burn as explosivly as gasoline does. so it may not hurt the octane rating but to a very small point does probably effect how the fuel burns.

 

i agree. i'm sure it affects it somehow but not enough for anyone to notice it.

 

No, but it definitely burns better than engine oil.

 

So my tank is about 16 gallons. I have an OMP that may or may not be working. I fill up to the top everytime.

so for 16 gallons, 8 oz. of 2 stroke is a good choice?

 

Well to keep in mind. 2 stroke is good for your car because it lubs your apex seals and what not and yet it will clog your cats very quickly so haha I would suggest running straight pipe or unless you would want to keep buying cats.

 

1oz. per gallon? so 18.5 oz for S5? Can any of the gurus confirm this? Seems like a lot of 2 stroke to me. WOuldn't it foul the plugs with that much 2-stroke?

 

it cant possibly clog cats that fast. ive heard it might smoke a bit more than normal, but not enough to destroy your converter in a few months. maybe a couple years...

correct me if im wrong.

 

been running straight pipes for years. the only cats I know are *****-cats.

 

i have to go through emissions where i live so no cats isnt an option.

 

Id imagine it WOULD clog them, eventually. But I dont see the small amount of oil being burned in the gasoline clogging them that fast. Then again I dont deal with cats either, so what do I know. 8oz per 16 gallon is approx 250:1. That might be ok, but I like to run a bit more to make me feel better, like I said, I run 16oz through in about 2 or 3 fuel ups (I ussualy dont fill up all the way, normally only 3/4 tank or so). Id say maybe 12oz per full tank would be about right. I see this more as a preferance thing. No 2 people here probably run the same number, unless they both are going by what someone else said.

 

my main concern is going through plugs every 3K miles

 

Ive been running heavy premix since I picked the car up (approx 4,000 miles ago) and they still do just fine. I take them out every so often and spray them off with some carb cleaner and let it eat off some of the carbon and other junk. My car isnt a good indicator though as its pretty worn out anyway. Even so, what does a set of plugs run you? $20 every 3 or 4 months if that often

 

more like 40-50 bux but still slightly unnecessary.

so what is the worst case scenario if your OMP fails and you're not pre-mixing?

 

None if you catch it in time. If you let it go for a long while Id guess youd see alot more internal wear and possible premature seal failure.

 

cool. I am not losing much oil and I was told a while back (when I was buying the car) that the OMP was on it's way out. I kept fouling the plugs so I stopped pre-mixing but i might have to take it up again.

 

A few things happen when you have no premix or omp. The housings and apex seals wear prematurely not to mention they don't seal as well. The oil lubes the seals for movement as well as friction where they ride against the housing. The premix at 100:1 definitely doesn't clog the cats or foul the plugs, running rich will. Or some other problem such as burning too much oil(bad oil control rings and such). If your unsure as to whether the omp is working test it as per the fsm or simply remove it and block it off. Which is what I've done on all of mine and recommend it to all my customers. It's just a safe bet. So there's my 2cents, hope it helps.
BTW it's about 600ml per tank. You'll have to convert it to oz's. A little more than 1/2 a quart. If that helps.

Brent

 

rock on. Great info.

 

Brent's the man!..he knows his stuff....NOW..IF I would be Premixing,I would NOT be just Pouring the Stuff into the tank..I would at least have a Small jug that I could Shake a Mixture in,and then Pour the gas/Oil Mix into the Tank(like a ONE gallon gas can)..That way it will not be "Clotty" in the Tank,and would mix with the Rest of the Gas IN the tank more Easily...and The Guys that have been premixing have Been Using ONE Bottle to ONE Tank..So if the Bottle is 16 Oz and the Tank is 16 Gallons,That works out to One OZ Per Gallon..

 

Well 2 stroke oil seems to mix in with gas pretty easily. I just poor it in using the spout that comes on the 16oz bottle, ahd hold the gas flap open with a screw driver. Once you drive for a few minutes, the starting and stoping along with turning will slosh the gas around enough for it to be mixed pretty well. Doesnt take much