Morris Minor Owners Club

In a lifetime of dealing with BMC/BL/AR/MGR, I have never once modified an A series engine for any changes to fuel composition, and have never had a problem. - Discuss....

What’s there to discuss ? You have no issues !

I've mildly modified my engine giving it enough extra umph to pull a 3.7 diff. The longer legs have dulled the performance down but the higher gearing means more relaxed cruising and just about the same economy figures.
I have modified my '71 Commer PB camper by fitting a Sunbeam Rapier engine with gas flowed head, SU HIF44 carb, free flow exhaust and overdrive. The performance has been dramatically improved (had it round the clock)and the MPG figures have improved from low/mid twenties to over thirty on a run. Tuning for power can also have other benefits as long as you aren't to heavy with the right foot

I think this is about whether it is necessary to modify the engine for unleaded fuel or for unleaded fuel with ethanol in it as we have now.

I ran my Morris until this year on unleaded fuel with no modifications from when leaded fuel was no longer available. I did use a fuel additive but it is debatable whether it was actually necessary. I had to replace the cylinder head gasket this year due to oil leaks and at the same time I fitted a cylinder head with hardened valve seats specifically for unleaded fuel.

As for ethanol, I had some fuel leaks and used new seals and fuel pipes rated for ethanol containing fuel. I cannot say whether the old parts failed from old age or accelerated ageing from ethanol.

I do use a fuel stabiliser over the Winter period. Ethanol containing fuel goes "off" much faster and this is mostly due to the ethanol being hygroscopic and oxidation to corrosive substances which gum up the fuel system. I use the same stabiliser in petrol powered garden equipment to excellent effect.

So, I would say if everything is working fine then there is no need to change anything but when fitting new parts it makes sense to use parts designed to last with modern fuels.

Stephen

I use E5,although I had to put in a half a tank of E10 at a rural petrol station recently as I had nearly run out and they had no E5. I didn't unduly worry about it but did fill up again with E5 when I ran low again.

@sevendin I’ve just had my Traveller converted to unleaded in the same circumstances as you. What is the fuel stabiliser you use and how much do you put in? Thank you.

CG75 wrote: ↑Tue Dec 12, 2023 7:15 am @sevendin I’ve just had my Traveller converted to unleaded in the same circumstances as you. What is the fuel stabiliser you use and how much do you put in? Thank you.

I use this: https://www.sta-bil.co.uk/products/sta- ... er-4-sizes

I only use it if the car is not going to be used for more than a few weeks. I also use it in garden machinery over Winter. 90 ml does a whole 6.5 Imperial gallon tank (29.55 litres)

Stephen

@sevendin Thank you!

Checkout the full range here?

https://www.ebay.co.uk/sch/i.html?_from ... =0&_sop=15

John ;-)

@sleeper Thanks John!

Modern fuel goes off quicker than old four star ever did and ethanol is much of the reason. Although I have lead free heads, I use https://www.millersoils-shop.co.uk/vspe ... -multishot, simply to combat the adverse effects of ethanol (Like damaging the cork seal around the fuel gauge sender). I only ever use super unleaded fuel.

Blaketon wrote: ↑Sat Dec 30, 2023 11:11 am simply to combat the adverse effects of ethanol (Like damaging the cork seal around the fuel gauge sender).

That would depend entirely on the compound used to bond the cork granules together....

I found this research paper from 2010
https://www.researchgate.net/publicatio ... nol_Blends

"The main conclusion is that the composites tested have shown to be suitable for the sealing of blends of gasoline with ethanol, in particular with high percentages of ethanol"

There's a lot of factors to consider, including the thickness of the material and the torque of the fasteners holding it compressed...
It's an interesting read.

In the absence of knowing, best to play safe but cork gaskets (Along with many things) have been highlighted as problematic. Hopefully, given time, better understanding will be obtained and changes made but I think it best to avoid ethanol as much as possible and to take steps to combat it.