13 replies to this topic

[dale23mini]

New to this forum purely because i have a rover mini checkate 998 and i have been running on leaded fuel for the last two months, this is realy expencive and i wish to convert my cylinder head to unleaded type.
i want to ensure the car is definitly leaded before i start.
can anyone give me information about my car .. VIN: SAXXL2S10xxxxxx

thanks.
dale.

[taffy1967]

Dale I think you may want to remove you're VIN number mate, because vehicle identity theft is rife.

Anyway I believe it's the engine number that is required for this purpose, but as you're Mini is a 1990 Check Mate LE then it would have been unleaded compatible from new.

Of course that's assuming that it's still fitted with it's original engine? If not provide the engine number, but you probably should change the last three digits to ### and then someone will be able to tell you for sure.

[mike49]

haha might as well type out ya credit card number and pin while ya at it! its 2007 britain!

[miniboo]

all we need to work out if you rhead is lead or unleaded is your engine number.

then look in the engine FAQ

[Dan]

The Checkmate should have a 99HF16 type engine, these are unleaded as standard. Check the engine number on the block corresponds to this and try to determine if the head has been replaced, someone may have put an earlier head on I suppose. If what you are putting in it is LRP please stop using it now, it's terrible unregulated fuel and really bad for the engine. If it's real 4 star then it won't have damaged anything because these cars have no cat but it will be a waste of funds.

There should also be a sticker on the slam panel telling you to use unleaded, it's probably got lost in the mists of time.

[205 tref]

sorry to hijack, but what Dan said about LRP caught my eye...

We're fortunate to have a couple of places round here with proper leaded fuel, but mostly we've just been using LRP from Sainsburies as it's cheaper and car seems to go ok on it.

Is it actually better to dose regular 95RON unleaded with an additive/use an in-tank fuel catalyst?

With regard to unleaded heads (hardened valve seats for exhaust valves?), I have a suspicion i remember the A series wanting the lead for upper cylinder lube too... am i imagining this? I'm just getting back into minis after years of fords, K-metros and pugs...

I'd never heard any serious bad news about LRP, but with the engines I've been running it hasn't been relevant, so I prolly wouldn't have taken any notice if i had!

Edited by 205 tref, 30 July 2007 - 08:34 AM.

[annodomini2]

Leaded or 4-Star as it use to be known is higher octane than unleaded.

[Dan]

Only if it really is 4 star you are talking about, leaded fuel of course came in many grades. 2 or 3 star were lower octane than unleaded. Octane and lead additives are unrelated really, the engine needs both for different things. The Mini was not originally designed for 4 star.

LRP fuel is garbage. It has no British Standard or other regulation and can be made of whatever they want if it will burn. There are many documented cases of long term use of LRP producing worse damage than simply using unleaded in a leaded engine will. When the government first restricted the sale of leaded fuel several fuel companies and classic car magazines ran tests of the various alternatives and LRP came out bottom in all respects.

In tank or in line fuel catalysts are a con. The lead added to petrol is not simply lead but a complicated compound of tetra-ethyl lead mixed in a very specific ratio with the fuel and other additives. British 4-star fuel is some of the highest quality and highest regulated petrol in the world, lobbing a brick of lead into the fuel tank won't do the same thing. For one thing lead doesn't actualy disolve into petrol on it's own.

If you don't want to spend out on real 4 star (although if I had a leaded car and a local supplier of Thrust petrol then I would be buying it) then the best option is an additive used with 95 ron unleaded. Castrol Valvemaster seems to be the most popular. It will raise the RON to about 97 (if you start with 97 RON it will come up to over 99), and contains a good mixture of protective additives. If the engine has a good lead memory you won't even need to add it to every tankful, although it is better if you do. Wait until a rebuild is required to make the full swap to unleaded.

A series engines don't need lead for any cylinder lubrication. They are very compatible with unleaded so long as the right valves and seats are used. Remember that petrol never used to have lead in it, it was only added so that car manufacturers could save money by not having to fit hardened valve seats. Japan never introduced lead to petrol and the Mini has been used there since it was first introduced with only an unleaded head being fitted. Some very early UK spec Minis may need parts of the fuel system replaced as unleaded will attack various types of rubber used in fuel lines, pumps and carbs. Other makes of car have this problem a lot more commonly, specifically anything using Lucas petrol injection.

[205 tref]

cool, cheers Dan!

I'll forget about the net bag of lead marbles someone was recommending to me then... As you explain it it sounds obvious. I feel a bit silly having believed in it!

Guess that'll be the Valvemaster then! We give the Min and the 104 the odd drink of proper 4*, but it's a 10 odd mile each way run on not particularly fast roads to get there and the place has mom and pop opening hours. The car gets used too much to depend on that as a source of fuel!

What we did find with the current additive (which might be Redex, not sure, looks like a redex style bottle in my memory) was that it was obviously packed for convenience and bigger cars. no way of measuring small amounts without taking your own syringe to the garage (!) just nice big grads for 55 litre tanks. OH was accidentally overdosing the car quite significantly, and while other stuff all went wrong about the same time, we had horrendous detonation-type smooth running problems, that i think must at least in part be the fault of the overdosing...

[205 tref]

the Huddersfield Sainsburies actually stopped selling LRP but then started again due to the number of complaints from local classic buffs!

[asbear]

My local Sainsbury's have finally stopped selling LRP.

I run an '87 Mini, (from new) Engine No. 99HB813*** (last three omitted).

I intend to use Castrol Valvemaster: what would be the best combination,
Valvemaster/Valvemaster Plus
Standard/Premium Unleaded?

Advice would be much appreciated.

Edited by asbear, 13 November 2007 - 05:37 PM.

[Ferrina1275]

Mainly all A series engines after 1989 are unleaded as factory standard. I recently bought a GTa Metro (1989) but found it was leaded. The engine is an MG Metro engine, last of the leaded one!! ( The guy ran it on unleaded with no exhaust valve burnouts yet!! I'm getting it converted for £117 through a local engineering company. I was going to run it on unleaded with an additive, but it's too fiddly remembering and unleaded is simpler. Shaell Optimax is good at 98RON and some Tesco outlets sell 102RON!! You could put in unleaded and a tin of Jet500 (Kerrosine jet fuel?) for lube.

[littlejem59]

My local Sainsbury's have finally stopped selling LRP.

I run an '87 Mini, Engine No. 99HB813*** (last three omitted).

I intend to use Castrol Valvemaster: what would be the best combination,
Valvemaster/Valvemaster Plus
Standard/Premium Unleaded?

Advice would be much appreciated.

I've been running Valvemaster plus with the Shell super unleaded for a while now on
standard ex seats, it seems to be o.k. on my 10.5:1 cr. It gives a couple more points
up the octane scale and added to the shell super stuff it works out around 100-101 and it's
not too pricy even in my local Halfords.

[asbear]

Thanks.
I'm not really interested in high performance as long as it starts and runs reliably without damaging the engine.
Might not a higher octane rating harm it?
And is my Mini (when new) cr also 10.5:1?
Considering the value I've had from it any extra fuel costs would merely be the TLC it deserves.

Sorry, posted in two different threads by mistake.

Edited by asbear, 13 November 2007 - 06:57 PM.