Morris Minor Owners Club

Hi everyone!

I was just wondering whether I should be putting additive in my moggy with the unleaded petrol?

Or should I use four star leaded as there is a garage near me that sells it?

It seems to me that some moggy owners don't bother with either of these solutions so why is that?

I know it's got something to do with valves but don't really understand anything about it.

Thanks a lot!

Kate

i dont normally bother

i drive mine everyday, but no motorways and it seems fine

you can get additives, castrol

The theory is that the lead, tetra ethyl or something, not true lead, acts as a lubricant and also forms a cushion on the surfaces of the valves and seats. This prevents wear on the surfaces and subsequent burning out of the valves. The cushion remains on the surfaces for some time so your engine won't suddenly blow up if you forget to use an additive one day.
When the original tests were carried out it was found that the A Series engine suffered from significant valve and seat wear, however these tests were carried out under harsh conditions which are unlikley to be frequently repeated by the average Minor owner.
You could always swap your head for an unleaded one with hardened valves, guides and inserts but why change a perfectly good head? Might as well wait until the head needs changing anyway then buy an unleaded one. Meanwhile you can use an additive if it makes you happy but keep to the same brand.

Thanks for that!

So what additives can you get and where can you get them from?

castrol valve master from halfords

Thanks! No one ever normally recommends Halfords for anything!

some of their gear is all right

I got a nice socket set there the other day for £9.99.

Although I've now got only unleaded heads, in the early days of unleaded petrol I used Castrol Valvemaster and highly recommend it. If you choose another brand then make certain that it is approved by the FBHVC, id it isn't then (a) don't believe the outlandish claims and (b) don't touch it.

If you just chug around and do only a few miles a week then don't worry about an additive (as others have said) but if you intend to use the car properly, which will include dual carriageway, long drives, and even motorways, then definitely use the Castrol. It's available in most car accessory shops.

Why not just use the 4 star leaded from your local garage? Or is it a lot more expensive than unleaded?

I haven't been to the garage to see how much the leaded petrol costs yet. Maybe the additive would be cheaper though. I'm definitely going to use it I think because I'm going to use my moggy quite a bit.

esm do valvemaster and valvemasterplus for a resniable cost bet its cheaper than halfords.go for valvemaster plus,it will give you a better performance.

For normal motoring - you don't need any additive, or 4 star. If you really WANT to put an additive in, the only one that makes genuine 'leaded' petrol is Tetraboost. This is the only additive that contains the original Tetra-ethyl Lead that was in good old Leaded petrol. As regulars on here know - I am highly sceptical of all the other non-lead additives. But you really don't need any additive unless you are planning high mileages with hard motorway driving. You DO need to keep an eye on the exhaust valve gaps - which should be set to 15 thou, and checked every couple of thousand miles until you are confident they are not closing up.

Thanks for that. Where would I get Tetraboost from? It sounds good.

castrol valve master is fine

Wow Tetraboost is a bit expensive for me. I had a look at their website and it's £120.

I think I'll use Valvemaster because it's under £10.

Yes - it is expensive (although that's for a case) - but is the only one worth using. Just don't use anything - it will be fine.

I spoke about this very subject to an engineer at machine shop that I use for re bores etc.

They are certainly not that convinced about its protective properties when it comes to the valve seat wear.

Although as Octane boost I have found it works wonders in my old 6 cylinder Jaguar, without it the engine has a tendency to pink, but then again that was designed to run on 5 star!

I still use it, but when my Minor gets its rebuilt 1275 midget engine fitted later this year I will cease to use it.

BTW, I use the Castrol product.

Ardenrun

Yes - the Octane boost is about ALL they do! This was the main 'worry' at the time of withdrawal of leaded petrol - people were all of a tizzy about what to do with the dizzy! Using the additive allowed the timing to stay as was . For low comp Minor engine - it's not necessary (or advantageous) to boost Octane - just retard the ign slightly if there is any pinking.

This a link for petrol stations that still sell 4 Star.

Ardenrun

http://www.leadedpetrol.co.uk/list.htm