Morris Minor Owners Club

Hi, I just bought a 1958 convertible, with a 998 cc engine. How much lead additive do i need for each litre of unleaded petrol?

Not a lot, if any. Does it not say on the can? Only worthwile if you are doing a lot of high speed driving, at sustained high revs, where it will protect the valves.

Just glug a drop or two in each time you fill up.

I use 1ml per litre of fuel, but as above it usually tells you on the bottle I think.My additive came with a measuring cap.

You don't need ANY! Just set the valve gaps at 12 thou inlets and 15 thou exhausts - and check/reset every 3000 miles......

if you want piece of mind for a very small additional cost add 1mm per litre of lead additive ,cost around a tenner for 250 litre,tho you can get it cheaper sometimes at auto shows etc,I do lots of ,for a moggie,of high speed driving and no problems at all and tappets ok after 4000 miles with out having to faf about with settings.

you pays your money and takes your choice good luck

Most of the additives are based on hocus pocus and 'faith'.......the only one worth ever considering is Tetra Boost. It's the ONLY one with Lead Tetra Ethyl in the mix, and so it can genuinely replicate Leaded Fuel when added to unleaded. You should in any case be checking/resetting valve gaps every 3000 miles - so it's hardly a huge task, and only takes 10 minutes or so!

i do 300 miles a wek in my moggie, m,oterway constant speed and rural during the week
i dont use additives and she seems good

aupickup has the evidence that you don't really need additives as he is a high mileage man (do you have your ex valves at 15 thou like bmc suggests?)


A tip I got is to mix 2 stroke oil with the petrol at a 1:100 ratio to lubricate valves, upper cyl. head etc. The only downside to this I can see is possibly the need for more frequent decokes.

ex valves set at 15

JOWETTJAVELIN wrote:A tip I got is to mix 2 stroke oil with the petrol at a 1:100 ratio to lubricate valves, upper cyl. head etc. The only downside to this I can see is possibly the need for more frequent decokes.

I wouldn't do this for more than the odd tank. One problem that 2 stroke bikes get is that after a while, the exhaust gets clogged with deposits from the burning oil, leading to poor performance. It then has to be cleaned out using a variety of methods (filling the pipe with caustic soda and leaving for 24 hours being a common one). Not sure this would really be possible with a Minor exhaust, due to the non-removable baffles and packing. Obviously at 1:100 this won't happen very quickly, but it's worth bearing in mind. The plugs may foul up more quickly too.

[quote="JOWETTJAVELIN"

A tip I got is to mix 2 stroke oil with the petrol at a 1:100 ratio to lubricate valves, upper cyl. head etc. The only downside to this I can see is possibly the need for more frequent decokes.[/quote]

Isn't that adding an additive to save the valves

Yes, but it's proper oil as opposed to LRP or whatever they put in lead additives.

I haven't done it myself yet but am tempted to give it a go, especially with today's ultra-dry eco fuels.

When I was ultra skint in the 60's,and could barely stand the cost of half a gallon,but not the shot of two struck oil I would on occasions use newtons straight 30 from my mates dad's shed,never had a problem but always worried in case I would