Any MGB GT tips

[cybermat]

I just bought an MGB GT 1978 plastic bumper jobbie - mechanically its pretty sound by the sound of things but the body is starting to wilt a bit.
tatty around the drivers side headlight and under the windscreen has some small rust holes by the look of things (Ebay special).
I thought it was worth a punt at only £500 with tax and test on it till October.
Now I don't want to leave the old girl to get any worse so I am going to start attacking the rust and getting her tidied up but I would appreciate any tips on areas to keep an eye on, bits that are prone to rot and wear etc.

the seller sounds quite genuine and they have looked after the mechanical side of things by the sound of it at least, though bodywork isnt their forte by the look of things although I am being slightly over mean as she isnt that bad really. Do the MG's handle unleaded ok, and if I am considering using her as a daily driver should I look at anything else - eg uprated brakes,electronic ignition etc ?

Cheers for any basic tips - This the Rover and the Daimler are going to keep me on my toes.

[Wicksy]

Just sold my B roadster and had GT a few years ago so know sommatt.
Rust in the sills, inner sills, front wing tops and lower rear arch, floor pans and front of rear arch are the real killers - PC are currently doing a resto on a GT so plug in to that to get the full horror story.
Mechanically they are really strong so if there is no smoke on start, no rattles apart from tappets which clatter anyway, the gears don't jump out and the axle is reaonably quiet she should last for years. Rads clog up and leak so keep an eye on it and the temp guage.
Keep the front trunions regularly greased and watch out for oil leaks - the diff and axle case need to be watched, top up regularly and replace seals to avoid seizure, also the crank rear seal invariably leaks with age.
They are lots of fun though and are suprisingly agile if the shocks are good - talking of which they can leak and become useless - replace with teles if they need replacing, that makes them handle even better.
Best thing about them though is you can get every single part, probably quicker than a modern and certainly cheaper

PS. had a Searle unleaded in the GT, it ran on and was not sweet unless you put super unleaded in. The 66 Roadster engine was a honey in comparisom, it had a fitted fuelcat and it ran as sweet as a nut on ordinary supermarket unleaded with no pinking and no valve recession. I have always had catalysts on my classics by the way and they really do work, this opinion is backed up by many miles and hard use too.

[JPB]

The bit about fuel cats working had me going for a moment!

In case anyone doubts whether the tin pellets are in fact no more than solid state snake oil, see the Practical Classics test with the ADO17 that had a freshly overhauled head and was run on nothing but unleaded for a few thousand miles. The car - an 1800 so relevant here - suffered from such severe recession that the head was scrap after, ISTR, around 4000 miles so use a recognised lead alternative or the real thing - Tetraboost - in anything with an iron head and no inserts or induction hardening as only [tetra-ethyl lead] can work in petrol, solids cannot be dissolved and any benefit in the pellets exists purely in the pockets of the vendors.

For the long term, exchange heads for the B are available cheaply and work out far easier than faffing about converting your own with seat inserts.

Sounds like a nice buy at that money though, I can't see any way that you could lose on the car and rubber bumper examples seem to be more popular these days as they're perhaps better suited to the daily grind or to people who touch park.

[Wicksy]

Re the fuel catalysts - anybody is very entitled to an opinion on tin amalgam additive to unleaded fuel but all I can say is that I have used such devices for many thousands of miles in a variety of engines - 2 MGB's, a Healey 3000 and my Princess 2200 - none of them suffered valve recession and performance was as running with 100 octane.
As a retired Aero Engine specialist I am well aware of the science behind the anti knock properties of fuel aditives and actually tetra ethel lead was only chosen by the US oil industry for convienience and cheapness - there are several other acceptable additives which would have worked just as well,
The convincing case for tin was established in WW2 with the Roll-Royce Merlin engine being operated by the Russians in the Hurricane fighter - the soviets had no access to the 130 octane AVGAS necessessary to make the engines perform properly. R-R chemists came up with the tin amalgam additive and this in fact was rather crudely added to bulk storage tanks and fuel bowsers - it restored performance and there were no more engin failures caused by detonation or other maladies linked to the poor fuel.
The main scepticism about this additive is that there is no "real" scientific evidence, such as back to bac ktrial or analysis results, it is purely anecdotal. The original wartime work was obvioulsy rushed and would have been classified as top secret - no known specifications or other documentation survived after the war, only in the heads of the people who marketed the first Fuel catalysts for automotive use.
It is claimed that a tin additive will increases the iso octane no of the fuel, delay the onset of knock and also protect valve and seat burn by a cooler charge temperature. I reckon that is quite valid based on my experience and I will continue to have faith in such devices.

[JPB]

Fair do, it's your engine and if you believe that it works and have managed to convince yourself that it can, in spite of being possessed of more than enough knowledge to realise that, in solid form it cannot; then that's what matters.
As you say, the evidence for is anecdotal, but the damage to the Practical Classics staff Morris 1800's head was real and it's that which makes their, and MIRA's tests worth far more than a mid 20th Century Russian anecdote in terms of the question of whether people ought to be using additives in iron headed engines with no physical adaptations in place - which of course they should - and as the OP asked the question it would be irresponsible not to base the reply to him in hard fact; the magazine's own long-term test of fuel "catalyst" products.

Do the MG's handle unleaded ok

No, Cybermat, they do not, not unless you use tetra ethyl lead or one of the tried and tested alternatives to it or opt for an exchange head. I also accept that some people report negligible recession in engines that are never driven hard and know that some iron heads (Triumph OHVs for one example) used to suffer from recession even with 5 star petrol when they were current, but in the vast majority of iron heads examined in the metallurgy labs at work, where the students "volunteer" to send them as and when they pull a head during an assignment, recession is observed. In fact, the only iron head I can remember seeing during the past seven years that hadn't suffered noticeably was that from a US import, 1968 Volvo 142S which may have been induction hardened.

[OneCarefulOwner]

Fuelcats are the homeopathy of the motoring world.

Many cars that are run gently on unleaded will do fine if the head's had thousands of miles-worth of leaded fuel run through it beforehand to leave some deposits behind; THAT is what's keeping the engine running, not metal pebbles wrapped in chicken wire. When those deposits are cleaned away (remember when they first introduced detergent in fuel?) or were never given a chance to form, we always get what happened in the scientific tests.

[suffolkpete]

Surely the question is whether the tin-based additive used in WW2 is the same as the bag of tin pellets in the petrol tank sold today. I personally doubt it. It was probably some tin-based chemical compound added to the fuel, that works in the same way as lead tetraethyl and Wicksy's description seems to bear this out. The bag of pellets is described as a catalyst, not an additive, presumably to explain the fact that once inserted in the petrol tank it sits there unchanged for ever. To act as a catalyst, it needs to be present where the chemical reaction is taking place, in other words in the combustion chamber, and this is clearly not the case.

[Luxobarge]

Here's an idea: run the car on unleaded, and don't worry about valve seat recession, because if this happens you can just tip in a can of "Engine Restore" and it'll all be fine again in a jiffy. Simples!

Opening up another can or worms? Moi? Surely not!

On a serious note, Pete sums it up well above: the operative word is "additive". I have no doubt that tin (or a compound of it) as an additive may well work, as per the aero engine story, but these "Brocade" things are not an additive, they are allegedly a "catalyst". Clearly not Tin material ever actually enters the fuel that gets burnt. Any half competent chemist can describe at molecular level the effect that a true catalyst has on any given chemical reaction, yet I've never heard even an attempt to do this with the fuel "catalysts", and I'm sure I never will.

[JPB]

...Engine Restore......

Ooh-er, we like a bit of Quentula here.

*Running for yonder hills as I write this.*

[rich.]

ive got a load of magic beans for sale, only £20 a bag..







beanstalk giant& treasure not included