43 replies to this topic

[mohammed]

Hello everyone..

i have a rover mini mayfair auto 1985..998cc.. how do i no if its leaded or unleaded..

thanks

mohammed

[jbs.998]

Mines an 86 mini Chelsea and it's leaded.
I use an additive.

[Huddley_Clubby]

i thought they got rid of leaded engines long before the eighties? i have a Austin manual 1985 998cc and its unleaded?

[andymini12]

I think it was around 89 they started making them unleaded?
But it could be unleaded if someone has changed the head to a unleaded one.

[matt615]

Yes Minis changed to unleaded engines in 1989 ish. So assuming it has it's original engine and hasn't been converted, your 1985 Mini would be leaded

[firefox]

1989 unleaded

Guide to Engine Numbers

Eventually i'll build this into a guide to Mini and Metro engine numbers. Telling you what they mean, how they break down and which mini's and Metro's have equivalent engines.

So far though here's a list of engine number prefix's which are compatible with unleaded petrol. It is only the head that is different, so you can use this information to source unleaded heads from breakers for your mini.

Here is a list of unleaded engine numbers for the 998cc engines.

99HF15, 99HF32, 99HG30, 99HG31, 99HG32, 99HG33, 99HG34, 99HG39, 99H/D81P, 99H/E20, 99H/E21, 99H/E22, 99H/F16.

All the post 1990 1275 mini engines are unleaded compatible, many of them have CATs so can only use unleaded. None of the pre 89 engines, or sizes other than 998 and 1275 can use unleaded, with out modification. Information Received from Barrett''s MG-Rover, Folkestone.

Edited by firefox, 19 December 2011 - 08:38 PM.

[mohammed]

thanks

[eeae6000]

might need to look at mine but been running unleaded for 6 months now no problems

[stretch tech]

if it is the original engine, it will be leaded as mini went unleaded in 89

you should put your engine number into guess works engine checker to find out more about it.

[Deathrow]

You should also use the search. This question has been answered many, many times.

eeae6000, you should search for something called lead memory, as if you're car is leaded, it's information you will want to know.

[Huddley_Clubby]

1989 unleaded

Guide to Engine Numbers

Eventually i'll build this into a guide to Mini and Metro engine numbers. Telling you what they mean, how they break down and which mini's and Metro's have equivalent engines.

So far though here's a list of engine number prefix's which are compatible with unleaded petrol. It is only the head that is different, so you can use this information to source unleaded heads from breakers for your mini.

Here is a list of unleaded engine numbers for the 998cc engines.

99HF15, 99HF32, 99HG30, 99HG31, 99HG32, 99HG33, 99HG34, 99HG39, 99H/D81P, 99H/E20, 99H/E21, 99H/E22, 99H/F16.

All the post 1990 1275 mini engines are unleaded compatible, many of them have CATs so can only use unleaded. None of the pre 89 engines, or sizes other than 998 and 1275 can use unleaded, with out modification. Information Received from Barrett''s MG-Rover, Folkestone.

is this why my 1985 998 works without modification?

Edited by Huddley_Clubby, 20 December 2011 - 01:33 AM.

[Deathrow]

1989 unleaded

Guide to Engine Numbers

Eventually i'll build this into a guide to Mini and Metro engine numbers. Telling you what they mean, how they break down and which mini's and Metro's have equivalent engines.

So far though here's a list of engine number prefix's which are compatible with unleaded petrol. It is only the head that is different, so you can use this information to source unleaded heads from breakers for your mini.

Here is a list of unleaded engine numbers for the 998cc engines.

99HF15, 99HF32, 99HG30, 99HG31, 99HG32, 99HG33, 99HG34, 99HG39, 99H/D81P, 99H/E20, 99H/E21, 99H/E22, 99H/F16.

All the post 1990 1275 mini engines are unleaded compatible, many of them have CATs so can only use unleaded. None of the pre 89 engines, or sizes other than 998 and 1275 can use unleaded, with out modification. Information Received from Barrett''s MG-Rover, Folkestone.

is this why my 1985 998 works without modification?

I think you're interpreting what that says incorrectly.

If your cylinder head has not been converted to unleaded using hardened valve seats then you are running on a lead memory in the seats. Once that memory wears off, your valves will start eating in to your head.

[Guess-Works.com]

If you want to know the factory spec of an engine...

http://www.guess-wor...Tech/engine.htm

[twrminisport]

This is all ridiculous.
It is not your "engine" that is leaded or unleaded. It is your cylinder head.

Therefore look at your cylinder head casting number.

Because BL used so many different heads for so long the engine number does not really tell us anything. This also only tells us how is LEFT the factory and not what it is now

Sorry for the attitude but you will need your head casting no. to be sure. (Its under the rocker cover in the middle under the rocker shaft.

Jesus

[Guess-Works.com]

This is all ridiculous.
It is not your "engine" that is leaded or unleaded. It is your cylinder head.

Therefore look at your cylinder head casting number.

Because BL used so many different heads for so long the engine number does not really tell us anything. This also only tells us how is LEFT the factory and not what it is now

Sorry for the attitude but you will need your head casting no. to be sure. (Its under the rocker cover in the middle under the rocker shaft.

Jesus

I'm afraid that at some point you've been seriously misguided...

The engine number tells you exactly the specification of the engine as it left the factory, ok, some of the information has been lost over time, especially information from the 70's, however, 80's onwards is very well documented...

The casting number on the head means very little, ie all 1275 heads post cooper S are 12G940 castings, whether it be from a GT, turbo, spi, Metro, unleaded or leaded, and the same is true for 998 and 1098 A+ heads which are CAM4180 castings, irrespective of their specification.