Adding two stroke oil in gas?

[johnl]

A lot of our setups use fuel to supress detonation and to cool the top end. This can acccelerate the advent of cylinder wall taper by way of the fuel "washing" the oil off the cylinder walls, especially near the top of the stroke. Also, with good stem seals, valve guides can wear out before cylinder walls & rings.

So, why not add a little two stroke oil to our gasoline?

If OK, how much?

What's the effect on octane? Compatible with ethanol blend?

[Directconnection]

Oil will decrease your "detonation suppression" as I see it.

Also, 2 strokes don't get their fuel from the top end... it enters mid-bore.

It might help.... but I am not feeling so sure of that

[turbovanman²]

I don't think it will help, all it will do is carbon up the engine, make it more detonation prone and raise the compression over time thus making it even more detonation prone.

Use a fuel treatment designed to lubricate the top end.

[T-Bohn]

I think, not so good...by adding 2 stroke oil you will be taking away fuel which would not be a good thing.

Stay away from bean oils. go full synthetic "premix" not injector oil. 50:1 is often used in 2 strokes so go higher than that. 75:1 100:1 but at those levels what does it really do??

[Mopar318]

Your going to lower the octane rating of the fuel therefor lowering the flash point temperature of the fuel (AKA pre-ignition)

My volvo 850 turbo had leaky valve seals, and now there is a hole in one of the valves.

Oil in fuel is bad.

[johnl]

Steve, most two strokes today are no longer pre-mix, of course; they direct inject their oil in several places - directly into the mains and even the big end; the wrist pin and cylinder walls get the atomized fuel/oil mix that results from oil injected at the carb or throttle body.

Yes, less detonation suppression, but how much?

Simon, as for carbon buildup, the new synthetic TC4 2 stroke oil is very clean burning, far less residue than back in the day.

Two strokes that run on premix need at least 100:1 and that ratio is mainly for the rollers and balls of their mains, rods and wrist pins; I suspect that they don't need as much oil for the pistons/rings/cylinder walls as they do for the bearings. So, I'm thinking that a light mix might burn clean and help prevent wear of our fuel soaked cylinder bores and valve guides.

There really is no oil that is better engineered for both lubrication and combustion than TC4.

[T-Bohn]

I have been thinking about how much oil, just to get a sense of it.

12 gallon tank @ 128 oz. per gallon = 1536

100 to 1 ratio would be 15.36 oz.

Is my math wrong??? This seems like a real lot of oil!!

[Johnny]

What about Rislone instead?

[RoadWarrior222]

ONLY one kind. TCW3 outboard oil, it's ashless and O2 and cat safe. The most you want in is 2oz per tankfull. It is actually effective for lubricity at 1000s to 1 ratios, designed that way so if you run your $5000 boat motor and forget to add it one time, it should live on the residue in the tank.... even though the spec might be 200:1

Anyway, you can pick up about 2 or 3% on fuel mileage from it, I was using it to keep fuel pumps alive while playing with various solvents and alcohols as additives.

Would very very marginally affect octane at 2oz/tankfull type concentration.

---------- Post added at 09:52 PM ---------- Previous post was at 09:51 PM ----------

What about Rislone instead?

that stuff is mostly solvents or paraffin/kerosene type fractions...

---------- Post added at 09:55 PM ---------- Previous post was at 09:52 PM ----------

Oh johnl must be talking about TCW4, which is next gen TCW3

[johnl]

Thanks for the correction, RW222.
I'm just confused, TCW3 is what I meant.

So, you agree? Can't hurt and might help?
Somewhere, with reference to outboards, I read that it also tends to stabilize ethanol blended gas? Is that true?

[RoadWarrior222]

Probably does, it helps stuff mix together (and stay mixed) including itself.

[black86glhs]

Use it during the wet season to control mosquitos.

[RoadWarrior222]

I don't think it will help, all it will do is carbon up the engine, make it more detonation prone and raise the compression over time thus making it even more detonation prone.

While I might suspect that yard tool 2 stroke mix at 20:1 ish would tend to do that, the outboard stuff is high detergent and ashless. Also de-carb additives that work out at several hundred to one mixes in a tankful are typically kerosene or mineral spirits, which are "oilier" hydrocarbons than gas, not sure actually how they're meant to work in the chamber, but know that you can dissolve and mobilise carbon with them if you're cleaning up a motor. It's probably just that carbon is hard to light off when it's plastered against the wall, and anything that picks it up helps it burn.

[Reaper1]

If you are using enough fuel to taper cyclinders in these engines...you are using WAY too much fuel!!!

Stay away from using 2-stroke oils in the fuel regularly. I don't see it being an issue every once in a while, but I still say...WHY!? These engines are designed to work as 4-strokes. With correct tune and mechanical set-up, and the internal seals functioning as designed...the issue you are describing should be non-existant.

How many have DOCUMENTED significant cylinder tapering in these engines?

[contraption22]

I think you are spending time coming up with a solution to a problem that doesn't exist.

[johnl]

Taper, in highly boosted engines does not exist?

Who's running stoichiometric at 20 pounds and more?
At 10 or 11:1, that's a lot of fuel and it doesn't compromise cylinder wall lubrication?

[contraption22]

For how much of your engine's total running time are you seeing those A/F ratios? How many hours of those conditions between oil changes?

[turbovanman²]

For how much of your engine's total running time are you seeing those A/F ratios? How many hours of those conditions between oil changes?

Exactly. If your worried about it, then get a Metro or Honda,

Seriously, run synthetic oil, add a fuel additive to lube the top end, run a proper tune and problem solved.

[contraption22]

I could see the concern if we see alot of Chrysler turbo engines smoking like old Mitsu 3.0's and have low compression issues, but we don't. More often than not, when I took apart a half-assed maintained 2.2/2.5, I saw good bores.

[RoadWarrior222]

That's not the reason why 3.0s smoke though... just pointing out.

Couple of BITOG guys seem to like TC-W3 better than top end lube....
http://www.bobistheoilguy.com/forums...at&topic=90452

BTW, pulled a couple of MSDSes for TC-W3, I'm noticing something.. the "oil company" TC-W3s have just high refined oils and kerosene type fractions, the "outboard company" TC-W3s have acid neutralisers, which might be a very good idea with ethanolated gas...
https://docs.google.com/viewer?a=v&q...wVg2zWQQ-VvyNw
https://docs.google.com/viewer?a=v&q...QEveCHM6hjS3cg

Plus there's the "proprietary" part of the outboard company stuff, which I have a suspicion might be burn catalysers or something...

Anyway, what I had been using was Evinrude stuff, I picked up a stash of at somebody's yard sale... I haven't used it heavily in the Escort, due to MPG yo-yoing all over from maintenance and tune issues, and attempting to investigate an in-port catalyst effect, but I used it steadily in the Voyager... was seeing 26 and 27 mpg with the magic recipe of 1oz TC-W3, 2oz IPA, 8oz methanol in E-10 gas... I have used it too irregularly to get stable mpg figures off since.