two stroke oil in petrol.

[alanbell]

. after speaking to several people who know a lot more than me about engines the advice is DON'T put any oil in your petrol, for the following reasons.
1. each litre of fuel will contain but 95/6 cl of petrol.
2. it reduces the octane rating of the petrol and may cause pinking.
3. the engine will run lean (see 1 above) and so run hotter than it was designed to do.
4. oil burnt and unburnt will depart with the exhaust gases causing a smokey exhaust.
5. the extra carbon in the exhaust gases will increase carbon deposits on valves, ports and in the exhaust.
6. carbs do not like oil inside their working parts.
7. oil deposits in venturis and inlet ports.
8. the combustion of the oil can cause glazing of the cylinder walls, not good.
9. 4 stroke engines get plenty of oil on their cylinder walls. that is why pistons have an oil ring to take it back to the bottom of the bore and so to the sump.
10. any 2 stroke oil that manages to mix with the car's lubricating oil will not improve its quality, au contraire.
Excel engines were designed to run on the octane ratings available in the 80's, an octane booster might be a better option.
if you disagree feel free to say so but do not expect an argument from me as i have not a wish to cause raised blood pressure or a heart attack amongst those of a delicate constitution.

[fueltheburn]

A mis-interpreted post.
Read the two below posts. Richard was talking about restore which is an oil additive to restore compression on failing engines. It works by filling in microscopic gaps between the cylinder wall and rings. In R. Goslings case his engine was too far gone for this and would possibly cause more damage as opposed to cutting losses and being able to salvage the engine at a later date.
I do however run two stroke in my diesel not petrol, my jag runs a delphi common rail system which is known to need extra lubrication in the fuel.
When you are losing an engine and it is your main source of transport... you investigate every possibility.
R.G will be up to speed on a lot of what floats around as heresay and what works as he is involved with engine design.

"

Another little 'I know what I'm doing' heresy of mine is to add a little 2 stroke oil to the petrol (approx 10ml/litre.) 2 stroke oil is good for several things:

- providing some lubrication for the cylinders in cold start situations (where otherwise all lube is washed from the cylinders by petrol)

- lubricating the fuel pump;

- resisting much of the damage that can be caused by ethanol;

- providing resistance to corrosion in the tank.

In addition it helps keep down carbon deposits (shouldn't be a problem on our cars!)

By the way, just to qualify my Engine Restore heresy, my Discovery MPI (OK I know another heresy but a least it's a twin cam) was burning around a litre of oil every 1000 miles. Engine restore reduced this to about 1 litre per 4000 miles, and improved compression by 15-20%. I merely report what I have found, and make no comment on the sometimes extravagant claims made for it. For me, it just worked.

Anybody got any other (Lotus related) heresies they'd like to share?

ATB Richard

I certainly use JASO-FB two stroke at 200:1 in the Jag diesel BUT it has been noted baby oil is better due to being a finer grade of mineral oil compared to that of two stroke.
The baby oil apparently has very good properties as an upper cylinder lubricant hence ised by old school tt-riders.

I would say in Richards case the ship sailed a loooooong time ago to be using any kind of restore.

Edit- I seem to remember Lancia sent out a technical bulletin suggesting a 3% petrol and two stroke mix to be added to a full tank for cars stored long term to stop rusting of the pintles on the injectors in integrales and to stop the fuel tanks rusting. Weird how I remember the most random things

"

[alanbell]

FTB, I was not addressing any previous post, otherwise i would written about the other things (heresies) richardw mentioned. i cannot help but wonder how one adds a 3% mixture of petrol and two stroke to a full tank as lancia seems to have suggested,

[chrisw2811]

I recollect that Esso, in the early to mid 1980s (when I worked for them) stocked clear plastic sachets of 'upper cylinder lubricant', which seemed very similar in colour and consistency to 2-stroke oil, to be added to a tank of fuel. It wasn't a big seller. A group of friends also used to add a capful of 'Castrol R' to the fuel in their Honda Supersport motorcycles. The exhaust smelled like a race bike's but, on engine disassembly, the piston edges and rings had a gum/lacquer deposit that was difficult to shift. For that reason I only add it to the fuel in my lawnmower, but the smell brings back great memories.

[richardw]

Alan - a quick correction - at a ratio of 200:1, each litre of fuel will contain more or less 99.5cl petrol and 0.5cl 2 stroke.

ATB Richard

[alanbell]

as i have said the post is not a reply to any previous posts in other threads.