MGB burning oil

MGB burning oil

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Discussion

ahockley

Original Poster:

136 posts

236 months

Wednesday 23rd January 2008
quotequote all
My MGB is burning oil to the degree that something needs to be done about it. Puffs of white smoke are evident on over-run, and I always have to top up the oil after even short (30 mile) runs. It is a standand 5 bearing 1800 from a ‘69 mkII gt.

I’m just investigating options: is it likely that a full engine rebuild would be required or just a top end? How would I know? If so how much would these two options cost?

Would a new or reconditioned engine that can just be dropped in be a better option?

Thanks in advance,

Alastair.

Huntsman

8,223 posts

257 months

Thursday 24th January 2008
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I'm in the middle of rebuilding an 1800 for put in my MGA, the bloke told me it was a good 50k mile motor, I gave him 80 and drove it home, reality was it was a knackered old smoker...

I've ended up fitting the following

big ends
mains
thrust washers
core plugs
releif valve and spring
piston rings
cam
lifters
cam bearings
oil pump
strainer
valves and guides

Bores, journals and rocker gear (oddly) were all ok.

They are simple engines and parts are cheap, so you might enjoy rebuilding one yourself. I would be careful about who I choose to buy a recon motor from, some are suspisciously cheap.....

If you do it your self you know exactly what you've got.

I've had good parts service form these guys

http://www.sussexclassiccar.co.uk/

HTH


wadgebeast

3,856 posts

218 months

Thursday 24th January 2008
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Depends on how long you've had the car and therefore know the mileage on the engine itself. Horses for courses.

Mine blew a piston ring about 110 k after its last rebuild. My options were:

- second hand engine - couple of hundred for the engine plus fitting
- exchange but reconditioned engine - ~ 800 quid plus fitting
- rebuild mine - 2 k total.

If you fit it yourself you'll save a packet, but I didn't have the space, a garage, half the tools let alone the time so it had to be done in a garage.

In the end I rebuilt my engine. It was a stage 2 lightened and balanced engine to begin with and had proved very torquey. The engine itself was sound and had 80k trouble free miles on it last year when the car did its disappearing act.

wildoliver

9,000 posts

223 months

Thursday 24th January 2008
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You have a few options Andrew:

Take your engine out, find the problem and solve it, the good news is it sounds like either bores/rings or valve stem seals. It would maybe be worth getting a head set and doing your stem seals, checking valve guides and having a look at bores one weekend. £15 for a headset tells you a lot and may solve the issue.

Option 2 is if you find it needs a rebore and rings, take engine out and have it bored, check crank journals at same time and generally rebuild engine. If you take it out one weekend and get it to the machine shop if you speak to them nicely it should be ready the following weekend. But your car will be off the road for a week, and you won't see much change from £300 in my experience once you have bought the gaskets, bearings, rings, pistons, boring, possible journal grinding, painting engine (because you may as well), new clutch, etc etc.

Option 3 is to take a punt on a used engine. £25-£200 B series are cheap, very cheap. I would go this route, if the engine is as bad as yours at least you can rebuild without taking your car off the road.

Option 4 is a total rebuild at a specialist. Anyone doing this work and offering a warranty for less than £5-700 is suspicious. They have to make profit after all.

I'll rebuild your engine for you if your stuck, but as I say quite often to people have a go yourself if you can, you can always come back to a specialist later if needed.

Huntsman

8,223 posts

257 months

Thursday 24th January 2008
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...and if you decide to rebuild yourself and need to tools to change cam bearings give me a shout as I got a set, anyone can borrow them, open offer.


ahockley

Original Poster:

136 posts

236 months

Saturday 26th January 2008
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Many thanks for your replies - skill and tool constraints prevent me doing most of the work myself, so I may look into getting a reconditioned engine to drop in solving the problem. Then I can fiddle/rebuild my current lump at leisure which may well entertain me for quite a while!

wildoliver

9,000 posts

223 months

Sunday 27th January 2008
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If you get desperate I've got a recon sat here I was saving it for my roadster but got a 1950 now.