Fuel for old cooper S

[gam]

My 1967 Mk1 S is back with me next week MOTd and insured ready. I used to run it on unleaded plus all the additives but now we have optimax so I am not so sure whats for the best? I have been told it will run well on optimax as this is closer to the old leaded fuel but I am not sure?

It is the original engine but has 1'3/4 su's that have new jets etc and the rest of the engine I am told has all the right bits - competion valves toughened valve seats and rods etc. Last time it was running it was just off 100bhp if this helps?

Any thoughts
Gam.

[cooperman]

My 1964 1310 cc 'S' has about 115 bhp with 11.1:1 c.r and twin H4's. I use Optimax with Castrol Valvemaster Plus and it runs very well. I have also used the BP Supreme which is like Optimax and that's fine as well. The Valvemaster Plus takes 97 octane up to about 100 octane and the lead replacement additive works fine. I have had the exhaust valves recess into the head a bit, biut only after about 25 longish rallies using up to 7000 rpm aqt time with very strong double valve springs, so I can't complain.

[gam]

ok I will give it a go. I was not sure if it would be ok as I put optimax in my Tuscan and did't get off the forecourt, engine went pop!

But the older engine should be simpler and a bit tougher.

Thanks If any one see's a little red cooper s flying round derby you know its ok!!

Gam.

[Extra 300 Driver]

gam said:

But the older engine should be simpler and a bit tougher.

Too bloody right! These are tough engines, when the fuel strike was on I used AVGAS in mine and it ran sweet.

Put 95 in the Cerbera once, drive like a dog for weeks.

[cooperman]

AVGAS 100LL is a great fuel. 100 octane, leaded and not too expensive. I often used it before Optimax came along. Although, apparently, it has a slower burn-rate than MOGAS, I never noticed this and peformance was fine.
By the way, for those wondering, AVGAS is 'Aviation Gasoline' and MOGAS is 'Motor Gasoline'.

[haynes]

Just to hijack with a dumbed down question, but whats Tesco stripey shopper 99 ron like, ok ok but Shell stations are pretty few and far between round here?

[cooperman]

I think the Tesco stuf should be about the same as Optimax and BP Supreme, especially with the Valvemaster Plus.

[love machine]

Use tetraboost tetraethyl lead, www.tetraboost.com Lead up 95 octane as it responds better than 98. Failing that run brush thinners with a lubricant.

In my estimation, the old stuff wins. And I'm an expert!

If you have access to a chemist, I can give you the recipe to make your own! (my 6th formers make mine!)