MG Midget Forum

I'm at my wit's end. I've successfully rebuilt about four 1275 engines before, but my latest won't cooperate. Rebored it .020" oversize, new pistons ,new valve guides, oil pump, timing chain, etc., after 5000 miles still smoked bad. Tore it down again, checked cyl. wall dimension and condition, looked perfect, re-honed cyls, new rings, new valve stem seals, put it back together, put another 5,000 miles on it still smokes bad, good compression, plugs stay very clean, good power, idles smooth. Anybody got any ideas? I've heard of putting Boraxo in the cylinders. a little afraid to try that. I welcome any suggestions Jeff.

What is your crankcase ventilation set up?
Could be that you are sucking oil into the intake if it is not set up properly.
If you are just venting to atmosphere though, I'm stuck for answers.

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Andy

NAMGBR# 20-7738

My MIDGET smoked really badly after a full rebuild.

Turned out to be the PCV Valve.

My 1275 has a cone shaped PCV with a flat top.

The PCV fits to the centre of the manifold joined by a small section of heater hose.

The hose from the timing cover goes onto the PCV.

These PCV valves can be cleaned out and have a functional rubber diaphragm and spring but in the neck there is a metal plug that corrodes over time and makes them unfunctional.

I replaced mine with a new unit which solved my problem.

The other issue is the wire gauze in the oil trap at the front of the 1275 timing case can shrink and fall to the bottom.

I have attached an article from GILLSPEED newsletter that might help.

How do you stop a Midget from smoking? That is easy, turn off the key.

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Ian:

Fire extinguisher?

Banana in tail pipe

Take away it's lighter?

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Mench tracht un MG Gott lacht!
(We plan and the MG God laughs!)

I go with PCV. But what rings did you use? Different rings have different break in procedures in order to get a good seal. Some even have different directions for honing.

Hide his cigarettes...

Perhaps a nicotine patch? It might hold some of the parts together, too!

Of all the suggestions above I like Roger's, Phillip's and Andy's.

Jeff, did you redo the head as well? Worn valve guides also could cause oil consumption.

Have you done a compression check yet? Maybe you have a problem with just one cylinder being bad.

Have you pulled the plugs to see what each cylinder looks like? If you find one or two of the plugs that look oil fouled or black possibly concentrate your search on those cylinders.

Do you have the vent running to atmosphere? From my own experience and reading the MG posts the venting of the crankcase into the intake may be the root of all evil (as opposed to money which by now your car has consumed everything you own)!

Boraxo......I like Mr. Clean! Although you know the Boraxo fix comes up often in my freinds discussion on American cars. I think that goes right up there with Hoodo Oil which is guaranteed to stop oil burning, prolong engine life, get 100 MPG, cure hair loss and increase your sex appeal!

Lets us know what you find.


Ice

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Iceman

Atlanta GA

71 MG Midget

62 AH MKII
67 Midget
71 Midget

Have you installed the oil rings correctly? If it us the type with the corrugated spacer then the ends must butt against each other and not overlap. Don't ask how I know! Get it wrong and it smokes like mad.

I always thought hoodo oil put too much hair on my sex appeal.

I can't resist,
Put up a non smoking sign.

seriously, are you sure the smoke is from oil burning or is it from miss adjusted carbs.
check your spark plugs... and compare to the many spark plug reading postings online

Y.