Forecourt embarassment - which fuel???

[abz 7001]

Suddnely realised we have been nonchalantly filling our new 87 998 cc mini up with Unleaded but she is a pre 89 model and no indication of "green pack" and no sign of cat (only about 20 quids worth of petrol in total and some of that was V power). Have popped in some fuel additive to rectify and will look out for LRP where available. Will this be enough to have damaged the seals or will we get away with it?

Suppose it could have been worse - could have been diesel!
Stuart & Dominique

[Plotloss]

Mine is UL but has no cat, its an 89.

I think UL valve seats came in in 88.

One tank will be fine, no worries there.

Alternatively, get some additive.

[abz 7001]

Cheers for the reassurance - its an 87 so I think may have the soft seals.
Doesnt matter anyway today, the missus phoned and said she took the Lotus as it was too dark at 6.30 this morning to drive without any lights. Either way rocket fuel additive has been added.
Cheers
Stuart

[wadgebeast]

Run the stuff on unleaded if you want, but expect to have to alter the timing slightly. Yes, it'll damage the valve gear eventually, but not for some time. That's when you buy a new head with hardened valves and just swap one for one.

If you've only just put replaced the head, you might want to use an additive just to lubricate the valves better and counteract the effect of the fuel's different octane rating prior to having the timing altered.

[Dino42]

The problem is with the valve seats in the engine, not any soft rubber seals.
Early cars don't have hardened valve seats so you can get valve recession after a period of time if you run unleaded fuel.
A couple of tankfuls of UL will have no effect at all.

Many people have run UL for many thousands of miles and not reported any ill effects, in fact it has been suggested that the simplest course of action is to run UL until you get noticible recession (keep an eye on the valve clearences - they will tighten up)and at this point rebuild the head with hardened seats.
Depending on the car and how you drive this could take years to happen.
Or you could just put in an additive - if you do this stick to one type, they contain different ingedients

[wildoliver]

I for one have noticed zero recession on very hard driven engines over vast mileages.

A 998cc mini in normal use should suffer no probs, but do adjust the timing if it starts to pink.

[love machine]

Just get the haynes manual for all metros (117?) and look up the engine code for unleaded 998's. Run the head until it shits itself and with all the money you save on not buying that expensive red stuff, get a head from a scrapper. I'll have a look at codes if you like......

[LazyDocker]

I've never had a problem with it. I used to just stick the red stuff through every now and then. I did thousands of miles like that, just had to adjust the timing slightly!

Anyway, changing the head on these is really simple and quite a quick job!