Unlead?

A vehicle where the engine components and setup are suitable for continual operation on unleaded fuel.

Or was that not what you meant?

An external examination cannot tell you if some engines may be used with unleaded.

Give the model and we will all know a bit more.

mrcheerful

Any car with an aluminium cylinder head is OK, because they all have hard valve inserts (alu is too soft on its own). Cars with cast iron heads may or may not have been converted, and some had hard inserts from new. Anything made after 1984 should also run on unleaded.

Cars made since catalytic converters were introduced (1991?) will have been built and set to take unleaded and will not need converting. A lot of older cars will also not need converting.

Unleaded capability depended on two factors. Whether the car's timing needed adjusting to take the lower octane rating and whether the car had hardened valve seats.

Do you mean 'cope with unleaded' rather than converted?

bear in mind that a lot of the converted pre-1990 cars needed a regular dose of leaded for the lubrication.

As I understand it you are going to look at mk1 escorts. You will have to take the sellers word as to whether it has been converted or not. Mind you the worst it will do if unconverted is burn the valves out, you could then get the head converted yourself.

mrcheerful

You need to know what is required for the particular vehicle, whether

Maybe nothing at all

Timing adjustment

Head rebuild

Occasional use of Leaded

And what works for what type of usage.

Then you need written proof that what should have been done, has been done. A sticker, or the assurance of the seller, is no good.

I wonder, could it be an '86 mini?

Steve

Apparently not, it is to do with mk1 escorts, my choice would be a bda engined one.

mrcheerful

Thanks for all replys. Sorry about misleading, as I am a foreigner.

I got a MINI, but it is not the one I talking about, because its already got sticker says "run on unlead".

The car is actually a 84 Merc 2.8 straight six. Does it got a Aluminium haed or a Cast iron one? Any idea please?

mini86 ( snipped-for-privacy@hotmail.com) gurgled happily, sounding much like they were saying :

It'll almost certainly be fine. I doubt Merc made two different heads - one for the US (which had been on cats and undeaded since '74) - so it'll be fine. Timing may have originally been set up for 98RON 4*, but it'll certainly be right for 95RON undeaded by now, I'd think.

The merc. 280 6 pot (engine code 110.988 1981-85) is suitable for unleaded. (Autodata 2004) Tell the exact model and I will double-check for you.

mrcheerful

Apart from early hard driven Golf Gti's, apparently. I've heard a few stories in racing circles about recessed valve seats.

-- r

MkII VW Polo FormelE's dont, and they were made until 1990.

:-(

Maybe I should have said "first sold after 1984".

It's a W123 280E, almost the last few cars of the 123series.

Both engine variations are ok on unleaded.

mrcheerful

Many Thanks