50:1 2 stroke in a 4 stroke engine?

[canoeman]

We have a selection of 2 stroke engines and 1x4 stroke engines.

Apparently someone, who shall be nameless, not me, has attempted to run our 4 stroke on 2 stroke fuel. Not to sure the result but do I have to go to the fad of draining the engine or will reconnecting it to normal fuel be OK?

 

[Chiara’s slave]

It’ll be fine. A bit smoky maybe til its all gone through.

 

[Refueler]

Exactly ... just fill up with straight petrol and run it ... plug would probably benefit from taking out and cleaning ...

 

[canoeman]

Just run it with 4 stroke fuel, started immediately, at bit smokie but that has cleared. I suspect 4stroke through a 2stroke engine could lead to over heating and damage.

Now off to label the fuel tanks

 

[Falling Star]

It's lucky that the nameless one didn't do it the other way round.........

 

[Chiara’s slave]

It's lucky that the nameless one didn't do it the other way round.........

Things are apt to get hot and squeaky rather quickly in that case.

 

[Snowgoose-1]

What would happen if you ran a two stroke fuel mix into a 4 stroke with no oil in it's tank ?

 

[nortada]

What would happen if you ran a two stroke fuel mix into a 4 stroke with no oil in it's tank ?

Why would you

Not an experiment I would advocate.

 

[snowbird30ds]

What would happen if you ran a two stroke fuel mix into a 4 stroke with no oil in it's tank ?

Two stroke oil in the fuel will only lube the bore in that case, the rest would be knackered very quickly.
It also runs weaker and hotter using 2 stroke in 4 strokes.

 

[Chiara’s slave]

Two stroke oil in the fuel will only lube the bore in that case, the rest would be knackered very quickly.
It also runs weaker and hotter using 2 stroke in 4 strokes.

You might get 5 minutes of idling before permanent damage.

 

[billskip]

What would happen if you ran a two stroke fuel mix into a 4 stroke with no oil in it's tank ?

Can you walk on water?

 

[Alicatt]

Two stroke oil in the fuel will only lube the bore in that case, the rest would be knackered very quickly.
It also runs weaker and hotter using 2 stroke in 4 strokes.

My IT465 Enduro motorbike recommended 35:1 2stroke mix for normal street running and 50:1 for racing

 

[Mark-1]

What would happen if you ran a two stroke fuel mix into a 4 stroke with no oil in it's tank

Totally different engine designs. 4T engines have valve gear on top, as you know, and the petrol mixture doesn't touch those, they rely on oil pumped from the sump. Also the big ends etc. In a 2T engine the mixture goes through the crank covering the con rod ends and main bearings in oil via the mixture. In a 4T engine the oil for that comes from the sump while the petrol goes straight into the cylinder with out circulating through the crank.

 

[Mark-1]

Two stroke oil in the fuel will only lube the bore in that case, the rest would be knackered very quickly.

...but if you used Castor 927 it would smell fantastic as it tore itself apart.

 

[ducked]

Some people run 2T oil as an Upper Cylinder Lubricant in 4-strpke engines.Has to be a low percentage (in the 500's to 1 range typically IIRC) otherwise if theres a catalyst its life will be shortened. I suppose maybe good for diesels on lowsulphur fuel. MPG improvements are claimed though I find it very hard to believe there is evidence for that.

2-cycle oil as a fuel add in 4-cycle engine

 

[Chiara’s slave]

Some people run 2T oil as an Upper Cylinder Lubricant in 4-strpke engines.Has to be a low percentage (in the 500's to 1 range typically IIRC) otherwise if theres a catalyst its life will be shortened. I suppose maybe good for diesels on lowsulphur fuel. MPG improvements are claimed though I find it very hard to believe there is evidence for that.

2-cycle oil as a fuel add in 4-cycle engine

Any fuel saved is probably as a result of slightly increased viscosity, and therefore less fuel passing through the jets/injection. Running lean is not a good thing. What you might save in fuel is offset by the increased wear.

 

[Snowgoose-1]

Some people run 2T oil as an Upper Cylinder Lubricant in 4-strpke engines.Has to be a low percentage (in the 500's to 1 range typically IIRC) otherwise if theres a catalyst its life will be shortened. I suppose maybe good for diesels on lowsulphur fuel. MPG improvements are claimed though I find it very hard to believe there is evidence for that.

2-cycle oil as a fuel add in 4-cycle engine

At one time, It was all the rage to use an upper cylinder lubricant to reduce start wear . You don't hear so much now. Perhaps high tec synthetic oil overcomes this problem ?

When I had a boat with a Volvo 2000 series engine, it required an extra splash of diesel instead of glow plugs at startup. I always felt that the bores got that extra bit extra lube when the engine was cold.

 

[ducked]

Any fuel saved is probably as a result of slightly increased viscosity, and therefore less fuel passing through the jets/injection. Running lean is not a good thing. What you might save in fuel is offset by the increased wear.

I find it pretty hard to believe there's any evidence for that, too, at 500:1

 

[Refueler]

At one time, It was all the rage to use an upper cylinder lubricant to reduce start wear . You don't hear so much now. Perhaps high tec synthetic oil overcomes this problem ?

When I had a boat with a Volvo 2000 series engine, it required an extra splash of diesel instead of glow plugs at startup. I always felt that the bores got that extra bit extra lube when the engine was cold.

Bob's worth of 2T petrol and a shot of Redex please !! Brings back memories of my Lambretta days ..

The gob' of diesel to start your V 2000 .. the diesel basically created a seal when engine cold ... plus acted like the Cold Start on a truck - where instead of heat - the truck CS was an over-ride on the fuel governor - allowing a larger amount of diesel to be injected ... its why later trucks had the CS button out of easy reach of driver ... to stop them using it to get up steep hills !! (I grew up with Bedford TK's .. TD's ... Ford D series .. Leylands etc).

 

[Beneteau381]

I

Bob's worth of 2T petrol and a shot of Redex please !! Brings back memories of my Lambretta days ..

The gob' of diesel to start your V 2000 .. the diesel basically created a seal when engine cold ... plus acted like the Cold Start on a truck - where instead of heat - the truck CS was an over-ride on the fuel governor - allowing a larger amount of diesel to be injected ... its why later trucks had the CS button out of easy reach of driver ... to stop them using it to get up steep hills !! (I grew up with Bedford TK's .. TD's ... Ford D series .. Leylands etc).

I remember the old engines as well, your anecdote doesn’t chime with what I remember! Most had a coil in the inlet manifold which had diesel dribbled on them to produce vapour or even flames!