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MG MGB Technical - Jobs for Engine Out

I'm about to pull my engine for a head upgrade, new clutch, new clutch hydraulics, new wiring, new mountings, new exhaust, tunnel inspection, general clean out and finally engine bay re-preservation.

There used to be a very useful thread on 'jobs for engine out' but it's disappeared off the archive.

It was suggested that I pop off the sump and replace some of the bearing shells - seems reasonable. BUT both the main bearing and big end bearing kits offered by MGOC are available in 6 different thicknesses.

How do I know which ones to order?
A Riddett

You won't know until you drop the sump and look at the bearings that are fitted.

You should be careful what jobs you decide to do when the engine is out. I got a bit carried away...

D O'Neill

Replace the oil pressure relief valve. Only costs about 7 but impossible to do in situ. and probably timing cover gasket and seal and check chain tensioner (a new chain is only about 8 too.)
Graham Moore

Also if its a five main bearing: A rear main oil seal.
A front gearbox oil seal and a sat of welsh plugs.

I agree that you need to be careful you know where to stop, as its easy to get carried away. Cost me $5k last time pulled the engine. If the oil pressure is good and running well?? A set of shells may be the tip of the iceberg. Denis

The more you do the more you are likely to upset, either from poor quality replacement parts or, dare I say, errors in installation.
Paul Hunt

Thanks chaps - all much appreciated. Fully agree with not getting carried away - but I've been working towards this, a little at a time, for ages and now I finally have the fighting fund to do it. The engine was running fine before I took her off the road nearly 3 years ago - she's been dry ever since but the engine hasn't turned. The problems of long term projects combined with being in the Navy!

So, once the sump is off measure the bearings and order - I have a set of verniers so no problem there. Oil pressure relief valve, happy, timing cover and gasket, likewise. I'll check the oil seal, might give that a go as well as the chain if I can persuade my Landy oppo to advise. Rear oil seal, again looks to be within my abilities. I've always ordered from the MGB Hive and they haven't let me down yet.

Overall the engine looks okay but there's a lot of corrosion around the lower front end, mostly where I've done various radiator-off jobs that have spilled coolant everywhere. One for the drill and wire wheel before I take anything apart! Then strip back the engine bay and start playing with various shades of dark metallic blue.

Paul, wise words indeed. My greatest challenge - putting it all back on straight!
A Riddett

If you do the rear main seal, it is also prudent to fit a speedi sleeve to the crank. When you do put some tape over the edge of the sleeve before fitting the seal and remove after fitting the sleeve. This stops the sharp edge from nicking the seal.

Herb Adler

If the welsh plugs aren't leaking, leave them alone is my advice. As for the bearing shells, you can tell what size you need by slipping out one of the existing ones and on the back will be stamped the size. It will probably say something like "Std", "10" or "20". This is the amount of undersize - standard size, or ten or twenty thou undersized. Check both a main bearing and a rod (big end) bearing shell as they could be different.
Mike Howlett


Sounds like a good idea to me - but I'm an amateur at best!

I've quickly searched and found suppliers - how would you go about ordering the right sized sleeve?
A Riddett

Mike, excellent, thank you. I hate adding up vernier readings in my head, had a right mare when doing the front stub axle shims!
A Riddett

You would only need a Speedy Sleeve if the area of the shaft that the oil seal contacts is grooved or pitted. Then you have to carefully measure the diameter of the contact area and buy the appropriately sized sleeve. They come in many sizes, each covering a small range of diameters. I had never used one in 40 years of car maintenance until recently, when I needed one for the front seal on the diff of my Lotus Elan. I was pleasantly surprised how easy it was to fit, and how effective it is.
Mike Howlett

This thread was discussed between 01/06/2014 and 05/06/2014

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