Morris Minor Owners Club

Falling at the first hurdle!!

Unleaded petrol in my 68 Moggy?? Do I need an additive? I have had a read through here, and some people say none needed, aothers say yes! So...?!

Obviously, I'd rather without, as it would be less expensive, but I don't want to do unneccessary damage to her!

This is the problem with talking to boys about my car, they just serve to confuse me greatly! What must you all think of me?!

Unless you plan to thrash it up and down the motorway a lot then plain unleaded should be fine.

Same again here. They were designed to run on pretty awful fuel from the 1950s. I've never added ANY to ANY of my cars and have never had a problem with ANY of them. In theory it reduces valve seat wear but I've never met anyone who can conclusively say that a lack of additive has caused extra on their car.
If you feel so inclined you could splash out once a year for some and add a small dash on long runs down the motorway.

Might be worth looking into Stabil for the fuel if you intend to lay it up for any period, though. It stops the 'goodness' evaporating out of the fuel during storage and I use this in my aeroplane. It will start much better if it has been stood with Stabil in it.

Ahhh now that is clear!! Thank you

Saves me worrying anyway

No additive needed - but it IS a good idea to set the exhaust valve gaps to 15 thou, and check/reset them every 3000 miles.

valve seat regression is real and proven on A-series engines in independant testing - however it'll take you ~20,000 to 50,000 miles of hard driving before causing any noticeable problems. If you plan to keep the car for a long enough to do 50k miles then using an additive will pay for itself compared to the garage bill for replacing/repairing the head.

If you want to use an additive, get one that is proven to work - some worked very well and some failed the testing.

Or do nothing and you may never get a burnt valve, saving the time effort and cost... and if you do then you can get an unleaded head at the same time.

So as long as you know the facts, then whichever choice you want to make is fine.

Thank you! And thank you for not patronising me too, I am very aware that I am probably asking stupid questions, but how else am I meant to find out other than asking people here that are familiar with the car & who know?! I like it here

I just want to look after my baby the best I can

The only stupid question is the one that you don't ask. If you need to know something then ask away, that's how we all learn.

Practical Classics magazine ran some tests and proved valve seat regression. The Federation of British Historic Vehicle Clubs has a list of approved (and tested) additives. My personal recommendation is Castrol Valvemaster (if it's still available?) for any serious road use of the car (eg daily commutes and fast dual carriageway work) or go for the unleaded head. As others have said, you can just run on the standard head with standard fuel, but be aware of the risks.

My side valve engine has been converted to run on unleaded petrol because all the mechanical bits are in the block so it made sence to do the work whilst the engine was being rebuilt.
With the Minor 1000 engine you might as well wear out the present cylinder head and if you ever need to then you can replace it with an unleaded head

Or just replace it with a very inexpensive second-hand head.......for another 50 k of motoring! The damage only becomes serious if you neglect to check/reset the exhaust valve gaps - do this regularly and it won't be a problem.

I have never bothered with additives. It takes many miles of hard driving before you will find serious effects.

After 20k miles, the money you save would easily buy another head and its not too hard to replace either. I do have a head in the garage that I paid to have converted and I'll fit it whenever I have to take the head off for whatever but that's only because its had so much performance work done to it that I want it to last!

The choice is yours. Additive might save you hassle in doing a head swap down the line but I wouldn't bother

Hello Rob,

"They were designed to run on pretty awful fuel from the 1950s."

That is not the same thing, fuel then was low octane but modern fuels have no tetra ethyl lead which definitely has caused problems to engines with soft valve seats. I would say that fact that fuel was poor then does not mitigate the possible damage that modern fuel can cause. Another problem looming in the near future is the increase of ethanol in petrol from the current 5% maximum to 10%, as a lot of material in older car's fuel systems are not tolerant of ethanol.

Alec

Alec,
There's a lot of hassle over here over that ethanol. The government is trying to push it at all costs. The environmentalists are up in arms and the public is boycotting it. The car manufactures will not guarantee it won't cause damage -it's just not selling.
Regards
Declan

Hello Declan,

interesting to see the reaction there. Apparently it can affect cars not much older tha 10 year old, never mind the age of our classics.

Alec

Another problem looming in the near future is the increase of ethanol in petrol from the current 5% maximum to 10%, as a lot of material in older car's fuel systems are not tolerant of ethanol.

My Minor would probably be less bothered about the 10% Ethanol than a lot of modern cars!
I've got 20L of E85 (85% Ethanol) whioch I wanted to try in a Minor (with timing adjustment) but I lost the motivation and it's sat in the jerry can for 3 years

Hello Ray,

you may like to take a look at the FBHVC's website and their list of materials that are not compatible with ethanol, even a common item like brass is affected by ethanol.

Alec

yes, brass, copper and and galvanised/zinc coated parts. Fortunately there's not too much of that in a Minor fuel system (unless someone made an aftermarket copper fuel pipe).
The most interesting part would be the fuel pump diaphragm, but not a lot of evidence suggesting problems.

as for vapourisation - that's going to be much more prevalent with E10

Hello Ray,

brass components in the fuel system, albeit substantial section, except for earlier H type carburettor floats, zinc coated fuel tank and the various hoses, whcih of course are easily replaced with compatible ones.

Alec

I was thinking that the fuel tank coating was tin - as many of mine have been rusty...
The tin can get eaten away with current fuel (e.g. E5) depending on a few factors.

I'd forgotten about the brass float in the carb
I seem to remember that later SU carbs had plastic floats (although I may be completely wrong!!) so that may be an alternative if people get perished floats in a few decades time.

As regards Diesel (not usually a Morris Minor issue!!) the change of viscosity with bio fuels can be a problem, and is well known for causing a blocked filter during inital use, as any silt in the fuel tank gets held in supsension in the fuel and ends up in the filter.

The feed pipe from the tank to the pump is copper! What about the main jet?