Morris Minor Owners Club

I have just acquired a 1968 traveller that is fitted with a 1300 marina engine, front servo assisted disk brakes and new diff. This is all good as it allows more modern driving.

My question is what is involved and roughly how much cost to convert this engine to unleaded?

Can I get the garage to fit a new head etc?

Hi, Speak to MM suppliers who can supply a new/reconditioned head to run with unleaded petrol. Bull Motif are advertising £137.95 exchange but there are plenty of others depending on where you live.

Alternatively take the Cylinder head off and take it to an engineering shop who can supply and fit new valve seats and also recondition the head for you if you need it. Lats time I done this it was about £120/30.

If a garage does all this for you expect to pay £25/30 per hour and in total it could be a days work depending on who does it for you.

If you give your location maybe you could get some recomendations of garages locally to you.

all the best, Jeff

Thanks for the info.

The car is currently in a Morris Minor specialist garage in West Malling - Kent for a bit of welding. I'll talk to them and see what they want to charge for the work!

If a garage does all this for you expect to pay £25/30 per hour

Our smaller local garages are more like £50-£60 per hour and we have a Volvo main dealer who has just hit £105 per hour................................................................................................

If the engine is running ok - just leave it alone! No need to worry about unleaded - it will go on for many miles yet. Keep an eye on the valve clearances - every 5000 miles will do. When the time comes - it will cost no more then than it will now - so meantime just enjoy !

Problem is where do I get LRP to run it on? Garages selling LRP are few and far between these days.

Lead replacement petrol? Or do you mean something else? If not, try using Castrol Valvemaster Plus. works a treat, and not much work when filling up!

Problem is where do I get LRP to run it on?

I'm guessing you meant 4-star. If you go to the main site and follow the links, you'll find out where you can get it.
Or you can use 'LRP' from anywhere - and cross your fingers that it does what it doesn't say on the tin.
Personally I'd rather save money and use a fuel additive that is proven to work.

Or you can play a bit of roulette and use unleaded and no protection. If the worst does happen then you can get an unleaded head conversion and feel happy that you've not lost anything by not getting it converted earlier.

Fuel additive seems the best way to go until I get an unleaded head. I used to have an old 1975 Series Three Land Rover that I ran on fuel additive and unleaded for a few years. That was quite a while ago now and I can't remember what the additive was.

Anyone got some names for tried and tested additives and rough costs?

Just use ordinary unleaded. My 1098 engine (295 head) has now done 6 years on unleaded fuel - no additives - no LRP - no 4 star - and the compressions are 160/170. It only does 3000 miles per year - but when it's running it's getting thrashed !

the stuff is cheap as chips, so i am not risking anything

My Traveller is likely to be doing 10-12,000 miles per year!

Well just use an additive if it worries you. I suggest the one that actually adds Tetra-ethyl Lead would be the one to go for !

Cool thanks

a really good option is Castrol Valvemester plus. Approx £10 a bottle in Halfords etc.. does 250 litres.
You can get it more cheaply direct from Castrol online (again follow the links from the main site - I presume they are still there but if not then we'll hassle Andrew/Billy )
The valvemaster (without the plus) is cheaper again but without the octane booster you can get into trouble with pinking a bit more easily (especially on a tuned engine).
As for the other additives, there are cheaper ones on the approved list but it depends if you can get them - not much point going for a cheaper one if you can't get any when you need a new bottle.

If you are sure you'll get the head done eventually, then you can just run without additive - if it's still fine after many years then you've beat the system.
There's no real right or wrong as long as you know the options and choose one that suits your use of the car.

Follow this link: http://www.fbhvc.co.uk/fuel/index.htm#add

For a list of approved and tested additives.

The point is this: Engines have been tested on a proper test bed to see the effects of VSR (valve seat recession) and running on unleaded alone DOES cause VSR. It's measurable and real. Just because you have been running for a while and your valve seats have not YET collapsed does NOT mean that they won't.

If an engine has been run on leaded for a while then there will be a lead build up which will protect for a short while but not forever! Especially if you thrash the engine.

If you use an approved and tested additive you will reduce the effect dramatically and prolong the life of your engine. ONLY use the approved ones though as the ones on the list have been PROVEN to work. The others (including LRP petrol) haven't.

The additive with real Lead is Tetraboost. Not cheap - but it does make unleaded into genuine leaded fuel - obviously must NOT be used with a catalyst! My 295 head had no 'lead memory' - the valves were heavily ground in before it went on the car. I'm actually 'willing' it to start leaking at a valve seat - because I have a better head just sitting waiting to go on !! However - I agree my car is just for fun - doing only 3000 miles per year - if you are using the car for serious motoring then it will be wise to get a proper unleaded head fitted. It is of course only the head (and valves) that gets damaged by the lack of lead - the rest of the engine couldn't care less !!

Yes, bmcecosse, that's very true about the tetraboost, but if you use an approved additive they all do a pretty similar job. I prefer Castrol Valvemaster plus because you can get it very easily (Halfords etc), but I suppose you could order a crate of the tetraboost.

Also unleaded is lower octane than the old 4-star (or LRP for that matter) so I use the additive with an octane booster. Lower octane usually means less power, hotter running engine and a tendancy to 'pink' and run-on. A splash of octane booster additive and your valves are protected and you are back to 'virtually' 4-star!

Yes - sure - but the tetra-ethyl lead IS an octane booster (or at least a 'knock' suppressor) . You would have to have a pretty fancy compression ratio to need to raise the octane number significantly !! The later Mini 998 A+ engines came out of the factory with 10.3:1 compression ratio - and run on normal unleaded.

Oh right so they don't do one without the octane boost then? Castrol do two types: Valvemaster (no octane booster) and Valvemaster plus (with octane booster).

Are you sure about the late 998 Minis?? I thought they were around the 9:1 mark? 10:1 is quite high for a production A-series. I thought only the MG Metro approached that value?

If you run 10.3:1 compression and 95 octane fuel you are asking for trouble!!!