I've got a MB question???????????

[Fabian]

Considering i get 4,000 kilometers (2,500 miles) out of a cylinder and 10,000 kilometers (6,000 miles) out of a bottom end using the cheapest 2-stroke oil at 25:1, there is no point in even thinking about the use of synthetic oil.

The extra cost of synthetic will not be proportional to any increased engine life.

It's the same notion that a top quality chain is better than a dirt cheap chain, which does not pan out in real life, considering that i have tried a $10 generic 9 speed chain and a $150 Wipperman 9 speed chain. The difference in mileage life span was an extra 15% over the dirt cheap chain, yet the top quality stainless steel chain cost 15 times as much as the cheap generic.

It would be a similar scenario for synthetic vs dirt cheap mineral 2-stroke oil, and a good part of the synthetic push was to enable running leaner oil/fuel ratios mandated by the ever tightening grip of the EPA.
Lean oil ratios are not compatible with Chinese bicycle engines because they are made from rubbish grade aluminium; giving poor materials stability; which requires a heavier oil/fuel ratio to create a barrier seal between the cylinder bore and piston rings.

 

[geebt48cc]

Fabian, then you are saying that using a cheap 2-stroke oil, vs a good synthetic 2-stroke oil at both ratio of 25:1, would both end up being the same wear on engine parts??

I know we are talking about very low quality stuff here, but using either or would be the same? Right?

 

[darwin]

If I was an amsoil dealer I'd say you can get 1000's of miles of extended life out of your motor and get 250 mpg using our magic in a bottle. Plus you can mix at 300 to 1.

 

[Fabian]

Only 300:1

I have heard some say that you can use that special miracle oil at 500:1 and it's "good for your engine" speaking in the most emotive manner.

_____________* You wouldn't want to hurt your engine *
__________________________________________________* You don't want to be a bad person*
__________________________________________________________________________________* You like to be doing "good" for the internal parts *

and you would never be seen engaging in mechanical torture by using bad old mineral oil that comes straight out of the ground; the very same kind of (non synthetic) oil that comes from the refinery and gets put straight into your fuel tank.

If only the petroleum companies could legally call their fuel "synthetic", they would be able to charge twice as much for the same product with a percentage of consumers falling over themselves to pay double the price,

because,

it's good for my engine

 

[Fabian]

Fabian, then you are saying that using a cheap 2-stroke oil, vs a good synthetic 2-stroke oil at both ratio of 25:1, would both end up being the same wear on engine parts??

I'm saying that at 25:1 (with a correctly jetted carburettor) it will make little if any difference to engine longevity using synthetic oil versus a low cost "air cooled specification" mineral oil.

 

[geebt48cc]

Just saying.......................

Ok then? I've seen first hand the difference internally of synthetic vs just regular oil! I know what we are talking about here when it comes to quality metals, but it was very obvious the different of wear between same engine parts that didn't use synthetic.

So, that being the case, one would believe that also you would find that to be true in just any type quality engine?

 

[Fabian]

In percentage terms, does the exta cost of synthetic 2-stroke oil vs the cheapest 2-stroke mineral oil make economic sense in the longevity of the engine, considering i can get 4,000 kilometers (2,500 miles) out of a cylinder (@ 25:1 oil/fuel ratio) and it costs $30 for a new cylinder?

 

[Fabian]

A 2-stroke engine does not use oil purely for lubrication and the lubricant value of the oil is only 1/3 of the equation.

In a high specification water cooled 2-stroke engine, the situation is greatly different to the Chinese bicycle engines powering our pushbikes.
Considering that those who use 2-stroke Chine bicycle engines are dealing exclusively with such technology, there is no point in trying to relate a higher technological specification to a rubbish grade (recycled) pots and pans quality 2-stroke engine.

Sometimes you just have to accept that you can't turn a sow's ear into a silk purse by using a high specification 2-stroke engine oil, nor greatly extend it's life span using a premium priced oil.

If i can get 4,000 kilometers (2,500 miles) out of a cylinder with the engine working it's guts out at virtually 100% duty cycle using the cheapest air cooled specification 2-stroke oil at 25:1 and a replacement cylinder is worth $30, why would i use a premium priced (ester based) synthetic and how much greater would the life span of the engine be prolonged by using a higher specification oil - 5%, 10% 20% ???

You can get premium grade synthetic 2-stroke oil for $40 per litre (quart), yet i can purchase a complete Chinese bicycle engine for $100.

I challenge anyone to build an economic case for using anything other than the cheapest (air cooled specification) 2-stroke oil in the cheapest sector of Chinese engines.

 

[crassius]

seems the question could be answered if the SAE rating on the container was higher for synthetic than for natural

 

[geebt48cc]

Very good point Crassius.

Have you ever thought about if using synthetic, in replacement to straight line 2-stroke oil? I bet it might double longevity from 2,500, to 5,000 before you have to worry about it?? (Not to mention bathing though's weak bearing, and just burning cleaner internally)

(Cheap or not cheap, it would prolong life)