DDK - Die Deutschen Klassiker

I read on a well known 'Air Cooled' Facebook page that if you are planning a long journey in your Air Cooled Porsche it's advantageous to add a very small amount of 2 Stroke oil to your fuel tank.

Anybody heard of this? Does anybody do this? and what are the advantages / disadvantages?

I have done many long journeys in air-cooled VW's and Porsches (plus my dear old Dad drove a Devon splitty overland to Israel and back just before the 6 day war...……. ) , but I've never heard that one before.


Unless of course you really want to be followed everywhere by a light blue smokescreen...…….


JW

Harry Pellow recommended using a pint of 2 stoke to a full tank of gas when breaking an engine in. I think times ( and fuel recipes) have moved on but here's a thread on the Registry that might shed some light.

http://forum.porsche356registry.org/vie ... =1&t=25480

mycar wrote:Harry Pellow recommended using a pint of 2 stoke to a full tank of gas when breaking an engine in. I think times ( and fuel recipes) have moved on but here's a thread on the Registry that might shed some light.

http://forum.porsche356registry.org/vie ... =1&t=25480

Really interesting read, safe to say I won't be adding any 2 Stroke to my fuel.

The Guy on the Facebook thread on Air cooled Porsche 911 & 912 swears by it.......I'll let him carry on

Abject ballcocks. If anything, you risk coking-up valve stems and combustion chambers.

That said, Marvel Mystery Oil... I recently had a sticky valve in a Lycoming O-360 (which is basically an upscaled VW Type 1), and read that adding MMO to the fuel can help to fix it.

I always imagined this stuff was just snake pish, cloaked in a screen of marketing puff, but within five minutes of starting the engine the valve was unstuck and smooth running had resumed. I've been adding it since.

Not sure how it'd benefit a long journey, but perhaps if you have a motor that's all caked-up because two-stroke has been added to the fuel, this will help clean it out

Oil goes in your sump, and oil tank, not in your fuel tank.
Good way to f up your carbs or injectors

Till the late seventy's nearly every petrol station in the UK had a large Redex oil can which you paid for by the squirt.
I live in Canada now but you can still buy what is called "top oil" in the Canadian Tire stores.
Also for a quick de-coke Redex was injected through the plug holes to loosen gummed up piston rings !

FedEx is an upper cylinder lubricant, different formula to 2 stroke oil which also.lubes the bottom end. Even better use castrol r like old school racing cars / bikes

Nonsense

I’ve twice done 1000 Miles in day in my 911 (Portsmouth to Venice) - no problems at all.

Would add coffee and red bull for the driver though

"Even better use castrol r like old school racing cars / bikes"
Even though it smells great it wont mix well with regular engine oil, it emulsifies in the piston rings.
Don't ask me how i know

Oil in the petrol will also cause the engine to run weak.

Does anyone know the Calorific Value of typical 2 stroke oils?

In motorcycle race engines these oils normally burn with the fuel and the high end Ester based oils used in Moto GP engines the CV seems to be around 40MJ/kg.

This is around 3.5% lower than a good quality fuel (43.5 MJ/kg)and in a very small concentration may not have much impact.

I am still not convinced it is a great idea but in low concentrations may not be too harmful.

Not sure on calorific value, but the flash point is about 240c which is quite a bit higher than petrol. Could this be being added with the intention of reducing combustion temps a bit?

I'm not sure how much is being added here, but guessing by "very small amount" its largely an irrelevance in 40 litres of fuel, assuming it will mix with petrol (which I'm thinking logically, 2-stroke oil is designed specifically to do). I seem to remember mixture ratios of >50:1 for a 2-stroke motor? And knocking on 1 litre in a tank isn't a "very small amount" in my head

In the bad old days a 2 stroke motorcycles 20:1 mixtures on old Villiers engines was a common figure.

This reduced to around 40:1 when 'Bardahl' became available and I used this oil in my 'Starmaker' engine.

I think some of the more modern oils can now be used down to 100:1

I would agree that concentrations of 40:1 compared to 20:1 need to be allowed for in terms of fuelling but the suggestion in this thread was to add small quantities which I presume would be similar to the old 'Redex' - - one squirt per gallon which is likely to be around 400:1 and I don't think that the initial suggestion was to use a full 2 Stroke Mix

Many 2 stroke oils have flash points at around 100-110 degC with some being significantly higher. and there is a list published on a us motorcycle website.

Amsoil Interceptor - 183 F
Amsoil Dominator- 194 F
Amsoil Saber Pro - 237 F
Maxima Formula K2 - 240 F
Maxima Super M - 280 F
Maxima Super M Injector - 220 F
Maxima Castor 927 - 420 F
Maxima Bio 2T - 180 F
Motul 710 - 190 F
Motul 800 - 485 F
Motul Bio 2T - 255 F
Motorex Cross Power 2T - 230 F
Lucas Semi Synthetic - 182 F
Bel Ray H1R - 435 F
Bel Ray MC1 - 208 F
Bel Ray Si7 - 194 F
Castrol Power RS- 163 F
Castrol 2T - 194 F
Red Line Two-Stroke Racing Oil - 221 °F

fetuhoe wrote:I don't think that the initial suggestion was to use a full 2 Stroke Mix

I was meaning that 50:1 seems significant for a 2 stroke engine in terms of lubrication/combustion, however a small quantity in a full tank of petrol (lets say 25ml in 50 litres) would seem almost an irrelevance to the combustion process?

From what I can see, it looks like redex might actually contain 2 stroke oil, plus some detergents and other bits?! So I'm thinking the intended benefit of adding 2-stroke prior to a long journey might be to help "clean the engine"? Makes me think its old advice (ie prior to redex, or for countries where redex isn't/wasn't readily available). If that is the purpose, I'm thinking modern fuels with more advanced additive packages/detergents probably outgun this solution anyway