Fuel and Oil

There'd be little point in using synthetic if the car has never had any in it. Most likely you'll find it's had multigrade (or even *really* old-fashioned single grade) used in it. It's not a new engine, and you're unlikely to subject it to driving stresses that will exceed its original lubrication requirement.

My advice would be to use Shell Optimax (forget LRP) and a recognised classic additive (millers?) without octane booster (or with octane booster if you want more pep, and fancy adjusting the timing to suit).

Don't think you'll get any benefit exceeding 97 octane even with any ignition tweak. 100 octane wasn't around when the TD saw the light of day. It may even be fine on 95 octane plus lead replacement.

Wasn't 4 star 97-98 octane in the pump?

Are those engines especially prone to valve seat recession or particularly difficult to repair when it happens? If not, I wouldn't bother with an additive at all. I've been running my Triumph Vitesse on straight Optimax now for about 17,000 miles with no sign of trouble.

The TD XPAG 1250 engine is a different kettle of fish from the Triumph unit. The XPAG engine has 30 degree valve seats which produce a valve quite thin round the outside edge making the valves more prone to burning, the exhaust gas temperature tends to be on the high side which dosen't help. Also different size of vales are fitted later cars the "TD2" model had the TF spec engine, with fairly masive valves that left very little "meat" between inlet and exhaust. It is also possible the head might be modified, most T Types had fairly large ammounts skimmed from the heads in the 60s so they were not to embarassed by 850 Minis. The good news that any of the Xpag/Xpaw engines I stripped in my TF days (OK -- a grand total of 3 engines :-) ) all had valve seat inserts (I might add very badly fitted on one unit)also the vale stems diameters are fairly enormous by moderns standards which helps cool the vale.

I would tend to play safe and go for unlead + additive -- this will also help the piston rings -- the top ring has a hard life on these engines as the pistons tend to run quite hot.

Duckhams 20/50 or something similar should be perfectly OK. There is no reason to go to fully synthetic, but if you go mad and do so, it might be an idea to use a flushing oil first as some people say the synthetics have been known to dislodge old gunge that normal oils leave undisturbed.

Don't use LRP. It can be horrid stuff, there is no British Standard for it and it is being phased out anyway. If the engine is still on its original

7.2:1 compression ratio, you should be OK on ordinary unleaded, but in the fifty-two years that it has been around, someone may have planed the head and you might have to go up a grade. I don't think there is a problem fitting hardened valve seats to this motor (though don't take my word for it, ask around) and unless someone has recently done work to it, it must have built up a pretty good lead memory by now, so I would be inclined to run the thing on the grade of unleaded on which it is happiest and keep an eye on the valve clearances. If they show any sign of closing up, which they probably won't for quite a while, whip the head off and get it converted. In the unlikely event of there being a problem with fitting valve seats, then use a lead substitute (with or without an octane booster), but otherwise save the money and put it towards the head job. It would also be a good idea to keep an eye on the fuel pump in case the diaphragm is an old one that isn't resistant to unleaded - or LRP for that matter. You don't say what fuel the car has been running on, or how much running it has done since fuels changed some years ago. It is possible by mixing some LRP's with the remains of some old cheap leaded to produce something rather like glue which, among other things, will make your choke control very stiff to pull out. If this happens the carbs need stripping and cleaning.

Good luck

Ron Robinson

I'll second the Duckhams recommendation. Good oil at a reasonable price.

snipped-for-privacy@zetnet.co.uk (Paul) realised it was 1 Nov 2004 06:11:09 -0800 and decided it was time to write:

Congratulations on an excellent choice.

I happen to have a workshop manual for the MG TD/TF, left over from before I matured and went into Triumphs ;-). According to this manual (which I highly recommend), the engine was made to take straight

30-weight monograde oil. The same stuff you pour into your lawn mower.

It'll be alright on any 20W50. I'd steer well clear from synthetics (I doubt you'll find a synthetic oil heavy enough), as the dopes in them may dislodge deposits that have accumulated in the engine over the years. Nothing wrong with deposits, as long as they stay where they are.

The important thing is how it retains its viscosity at temperature - and modern oils will be very much better than those when it was designed. A thick oil when cold is a waste of time.

They do make oil for older engines - these are better than modern synthetic oils - modern engines have closer tolerance and are designed to run synthetic oils.

Old-fashioned.

I wouldn't use a synthetic on anything with old-style seals; rope or scroll. They have a habit of finding leaks where there wasn't a leak before.

In news: snipped-for-privacy@4ax.com, Andy Dingley decided to enlighten our sheltered souls with a rant as follows

as anyone who ever put Mobil 1 in a Mini will confirm...

...or a Briggs and Stratton lawnmower engine... :-(

Regards,

Paul.

"R.N. Robinson" wrote in message news:cm5rki$hfc$ snipped-for-privacy@news7.svr.pol.co.uk...

Funny you should say that, Ron ;-)

Oh well, another job to add to the list :-). What would you clean the carbs with? Thinners?

Regards,

Paul.

A Mini without a leak before, though? ;-)

Or pukka carb cleaner. In terms of buying a small amount from an accessory shop, the pukka stuff is often cheaper.

5 litres of 'cleaning' thinners from a paint dealer is the cheapest way, though.

In news: snipped-for-privacy@davenoise.co.uk, Dave Plowman (News) decided to enlighten our sheltered souls with a rant as follows

Heh, I've never seen one.

Hey, _any_ oil in a Mini will find a leak somewhere! ;-P

"Dave Plowman (News)" realised it was Tue, 02 Nov

2004 00:08:32 +0000 (GMT) and decided it was time to write:

That's why I mentioned the mineral multigrade. Excellent stuff in such an old motor IMHO. Although for true originality, one should always use the appropriate monograde for the season, of course.