why we don't use 4 cycle engine oil in a 2-stroke

C

Chris Crew

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Several months ago, I started a thread questioning why we didn't just use regular 30wt engine oil as a cheaper alternative to 2-cycle oil. I had read that in China, 30wt is commonly used.

Surfing the web trying to diagnose a problem with my four-cycle boat motor turned up a very obvious answer:

2-cycle oil is designed to burn with the fuel---30wt is designed to NOT burn. If you were to mix 30wt with fuel for a 2-cycle, you would get some of the lubricating benefits, but you could also end up with lots of smoke from your exhaust and lots of gunky carbon build-up on your piston, ports, and in other places.

That about answers the question, but opens a new quest for a cheap alternative to 2-cycle oil.

Any ideas?
 
Chris Crew said:
....... but opens a new quest for a cheap alternative to 2-cycle oil.

Any ideas?
Click to expand...

Start your own castor bean garden and process your own castor oil.

With my 50cc moped, I get 100mpg. I figure I use $0.25 worth of 2stoke oil per gallon, so thats 4 miles for every penny worth of oil.

I suppose I could make that cheaper buying in bulk, but honnestly, I wouldn't want an alternitive to 2 cycle oil. It does a specific job realy well.
 
I have never tied it but I was once told that 25% diesel and 75% gas could be run in a two stoke but proper oil seems cheaper than a new engine. The source was a guy with an old Honda dirt bike. I buy walmart 2 stoke oil and the price never seemed high, but I'm also curious about other solutions one could use in a pinch like needing to refuel far from home.
 
Two stroke oil is cheap. You can get multi-purpose (outboard/air cooled) oil for around 15 bucks a gallon. That's a whole lot of premix for a 50cc motorized bike!

Even the racing 2T oils are affordable if you want the very best - but I doubt the racing stuff will make a difference unless you have a modified engine running high rpm all the time.
 
I use Amsoil oil at $9.00 a quart...cost more then most oils. At that price the oil cost $0.28 per ounce. Lets say the ratio will be 8 oz oil to 128 oz fuel (16:1). Fuel at $2.50 a gal all totals roughly $4.75 or if you get 100 miles per gal of mix that figure is $0.0475 per mile. If one needs to find a cheaper way to travel, buy bulk 2 cycle oil by the gallon at China Mart...or better yet peddle or WALK (but add the cost of shoes). At 32:1 you're now looking at $3.60 per gal of mix and $0.036 per mile. How much cheaper do you want from a motorized vehicle? Then again I'm looking at $0.28 a mile towing my fifth wheel, 5.6 times that of my bike. If this hits you wrong, I'm sorry but I can't see complaining about the cost of a few cents per mile on these bikes, unless you are somewhere where fuel cost $5.00 a liter. And North Carolina isn't one of them. Think about it...you pass more money in aluminum cans per mile then the cost of fuel. There you go...pick up cans and recycle them.
 
Dude.. Two stroke oil costs like, an insignificant amount.

The quest begins to not be cheap! Haha :)
 
chefdouglas said:
I have never tied it but I was once told that 25% diesel and 75% gas could be run in a two stoke but proper oil seems cheaper than a new engine. The source was a guy with an old Honda dirt bike. I buy walmart 2 stoke oil and the price never seemed high, but I'm also curious about other solutions one could use in a pinch like needing to refuel far from home.
Click to expand...

if you could get it to run on that mix, it won't run long, diesel doesn't not have any where near enough lubricating qualites to replace oil.
 
Many years ago i sprouted the idea that a 2-stroke engine may be able to run on "straight" diesel fuel, due the notion that the transfer ports are effectively working as a crude type of fuel injector, atomising the diesel as it's blasted through the transfer ports at high speed.

The method to test the idea was to run the engine with the fuel tank almost empty and then add straight diesel to the fuel tank.

Certainly was an eye opener as that little weed wacker engine filled the back yard with white smoke but the engine did indeed run on straight diesel and at similar rpm to running on 2-stroke mix.

I repeated the experiment a couple of times.
Upon stripping down the top end to check the condition of the piston and cylinder bore; there was no evidence of any wear.

If i had the machine shop facilities, i would like to try the same experiment with a high compression version of the already high compression billet cylinder head.

Fabian
 
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