MGB Engine Rebuild Advice

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Tue 7 Aug 2007 16:12
MGB Engine Rebuild Advice - stuartl
I have just bought a 1980 MGB GT that has sat since 1999. The engine starts and runs rough as one would expect after all that time but is blowing a good deal of smoke from the filler cap so I assume that the bores/rings are worn.

Has anyone any hints or tips specific to rebuilding one of these b-series engines other than the obvious swap to a V8?!?

Cheers,

Stuart
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Tue 7 Aug 2007 16:53
MGB Engine Rebuild Advice - Collos25
Before you condem it change the oil and filter and use some flushing oil first ,and then let it run for a while with some fresh petrol everything gets clocked up when they are left for such a long time .They are really simple engines to recon with all parts available as are body parts ring gear prone to wear and the king pins are ball ache if you reem them yourself. Loads of info available from the various owner club sites with loads of helpfull enthusiasts.
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Tue 7 Aug 2007 17:37
MGB Engine Rebuild Advice - 659FBE
The MGB has many problems (mainly corrosion and kingpins) but bore wear is not usually one of them. I would suspect that the piston rings are stuck in their grooves - in hindsight it would have been much better to free them before running the engine.

As you have run it already, I would suggest putting a small amount of graphited penetrating oil into each bore, turn the engine by hand a couple of revs, and leave overnight. Repeat the following day with thin engine oil. Then crank the engine on the starter with the plugs out to expell surplus oil. The first run will raise a good smokescreen.

As long as the engine is not actually burning much oil, a certain amount of "blowby" is fairly normal. Change the oil and filter more frequently than normal for the first couple of times and if your filter is mounted open end down, be very careful to get one with a functional anti-drain valve. Most cheap filters fail and some of the dearer ones do as well.

659.
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Tue 7 Aug 2007 17:31
MGB Engine Rebuild Advice - Victorbox
Agree with Andy B - give the rings a chance to unstick themselves - even try some Forte oil flush (most Vauxhall dealers sell it & others like ATS) and while you are giving the old engine a chance have a look around here www.mgbhive.co.uk/ and read up here
www.mgcars.org.uk/cgi-bin/gen5?runprog=mgoc&a=&p=e...l
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Tue 7 Aug 2007 17:33
MGB Engine Rebuild Advice - Lud
Put a lot of Redex down the caarb. That should help unstick the rings. Or put some in through the plug holes and leave it overnight, even better.
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Tue 7 Aug 2007 18:11
MGB Engine Rebuild Advice - stuartl
That sounds like great advice, many thanks!

I shall try the tips and report back on the results, cheers.
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