Some questions about my new MG B GT

Hi,

I ended up with an 1980 MG B GT when I came home from an auction the other week. Nice car as it is, I have a few questions.

I heard that the overdrive should automaticly disengage. I cannot hear a solinoid going when I go from 4th to 1st or reverse (with the ignition on and the engine off). Is it broken? Any good tests?

I need to change the wheel bearings. I saw this site [1] and it reakons you do not need the spacers and shims, and it is loads easier to change them without. Anyone else agree?

What is the best additive, now they are phasing out LRP at petrol stations? I should be able to put real 4* in every now and again.

I could pick up a new set of carbs for 90 quid. My mate reakons they would help with fuel economy and performance. What do you reakon?

Thanks for any help. I am sure I shall be back for some more advice. Oh, and if you want to see pics of it, they are at [2] (warning, pics are big, link is to an index). There are also pics of the other car I bought at the same auction for motorway use.

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Reply to
David Jones
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What price did you pick that up for?

there is an isolating switch near the gear change for that - it only allows it to operate in 3/4th so you should hear the click when throwing the switch on/off when in 3/4th position this solenoid click maybe masked when changing gears like you have mentioned. These OD units have an internal solenoid unit - where the earlier cars had an external unit. BTW does the OD work when driving? thats the most important.

Make sure that you change the oil and clean the filters use the correct oil when refilling.

There are heaps of cars that don't have this spacer and shims - but I like the spacer and shims so the nut tightening does not flat spot the bearings

I think this should have an unleaded head by 1980 if not get the head serviced with new valve seats and run the best unleaded petrol. The additive I use is flash lube with unleaded premium plus fuel.

Yep go for it as when the carbys wear its a bugger to tune and 90 quid is cheap.

Reply to
Rob

543 GBP. Not bad I thought. Not exactly the sort of car I went to buy, but I have always liked the idea of these cars, and now I have one.

I do like it. It is slower than I had expected, but I love the way it handles.

Yes, it works fine. I am just being very carefull to make sure I take it out of OD when I come out of top gear, to be sure it is not in when I go into reverse.

You mean the engine oil? Of course I will use a new fillter and the right sort of opil according to the manual.

I shall try and get them on then.

Really? That would be great. Any way to find out?

I expect I shall go for it then.

Thanks for the help.

Reply to
David Jones

Looked fairly reasonable condition.

There is one for private sale here all original low miles $10,000 AUD (4200 UKP)

Not sure what suspension it has but there was a tuning book around which stated you had to increase the rate of the shocks to make it handle better.

the isolating switch will do that - not to worry.

No the gearbox/OD oil there is a flat filter under the large bottom cover on the OD also there are magnets in there as well. The smaller square one with the writing info on has the solenoid under that.

Its not difficult to retain the spacers and shims when replacing the bearings.

lead replacement fuel is rubbish. I have been using unleaded since the leaded fuel was dropped although lead replacement was around. Now there is only unleaded. We have a standard, premium and now just recently released an optima (97 oct) fuel which I use. Mine now (Very early -

1962 MGB 3Brg motor) has a bit off the head etc and it pings without the best fuel.

They were exporting them to the US and by then they had to comply with US emission rules. Also there were high and low compression motors.( this will have a L or H in the engine number.

Reply to
Rob

yeah, it is not that bad. The passenger side door is really rotten, and the rear secion of the wheel arch on the same side is pretty bad, but other than that it seems pretty solid.

:-) The cheapest I could find around here that is not a project is about 1200, so I thought I had done well. All a bit academic when you just want to drive it though.

Interesting. I have not really driven something as sporty as this before (the closest was an E30 BMW 320i) and I thought that the weight transfer was amazingly easy to deal with (for eample on a quick left right or when straitening up off a powerslide). I guess faster shocks would make it even better.

As long as it is working. I guess if it is internal I could well just be not hearing it. It would be nice to know though, before I break it totally.

I shall have to have a look at it. If I get it high enogh in the air doing the wheel bearings I may do it this weekend.

I guess I shall try it with the diffent grades of fuel. It would be nice to know if the head is prepared for only unleaded fuel though. It is a bit of a way to the nearest place that sells leaded, and it is very expensive.

Interesting. And the high or low compression engines mean what exactly? ;-)

Thanks again.

Reply to
David Jones

Use unleaded, I say. Higher octane may allow the car to run cooler.

The reasoning for this advice, the thing that suffers from VSR is the exhaust valve seat and if the head (if it's a v8, "heads") isn't capable of running with unleaded that it will show up by the valve seats / valve seat inserts wearing out, essentially by developing little craters and that.

The fix to this is to press in new valve seats that are steel capable of being an exhaust valve seat in a car running unleaded.

Alternatively, you can avoid wearing out the valve seats by pressing in new valve seats that are steel capable of being an exhaust valve seat in a car running unleaded.

Basically, you can spend money fixing the problem if it happens, or spend the same money in some years if and when it happens.

Higher octane fuel is another issue altogether, advancing the timing back to use the full potential of higher octane fuel means more of the energy (which is about the same with low or high octane) goes into forward motion rather than heat. Note that this is not the same as leaded where you can run a tank in every every three of unleaded because the engine bits are coated and stay that way for a bit.

If the engine isn't tuned for higher octane (and it wont have an ECU that can retune the engine dynamically unless it's seriously non-standard!) it won't benefit from it, and you might as well use regular. If it is tuned for higher octane, it'll probably pink and predetonate whenever you use regular, so this is a tricky balance to draw. I think you'll find the engine more lively with tuning and the premium fuels and it'll do more mpg too, but the fuel price will be higher - whether you will save money as well as the greenhouse gases is a thing you might want to test.

Lead replacement additives cost vastly more than the fuel per litre, you can see this quite easily. Over the life of the car they also cost more than just sorting the heads.

Reply to
Questions

That you can run a lower octane fuel. The difference being the deck height of the pistons - not the combustion chamber volume. The engine number should start with some thing like 18GBRUH 1111111111 where 18

1800cc G as in MG and the last letter is H as in High compression.

Reply to
Rob

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