Place your bets please

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BMWChris

Original Poster:

2,022 posts

205 months

Friday 16th October 2009
quotequote all
Going to remove the head from my Midget 1500 to investigate symptoms below. Who is going to predict what I find?

The car has been used for competition (rallies and hillclimbs / sprints mostly) for the last few years.

Has always had a puff of smoke on full bore gear changes. Oil consumption always high, probably because of extra oil feed to head. Two events ago had ingested a lot of dust. When I cleaned out the intake trumpets the cleaner ran out brown. It also got hotter than usual but not enough to cause overheating symptoms. Possibly a little smokier at last event but not dramatically so.

Was getting smokey on long drive from Norwich to Prescott but seemed to be intermittent. Ie sometimes high revs lead to visible smoke in the mirror and sometimes it didn’t. Oil consumption rising.

Near end of journey dropped onto 3. Had oiled up number 2 plug. I cleaned it and the car restarted and ran on four. Also retarded ignition (wound along way forwards by previous owner with impressive power results) because now concerned about competing and getting home, not setting great time.

4 runs up hill. Smokey (mentioned by commentator – embarrassing!). Seemed to run ok.

Journey home uses 7 litres of oil! (about 3 times “normal”). And dropped onto 3. Cleaning plug didn’t work, nor did swapping it for another one. Oil pressure gauge stays showing normal and no obvious bottom endy type noises.

So what will I find?

shouldbworking

4,773 posts

218 months

Friday 16th October 2009
quotequote all
I'm betting on a high amount of general wear, with particular emphasis on knackered valve stem seals smile

52classic

2,629 posts

216 months

Friday 16th October 2009
quotequote all
Valve stem seals very bad. A couple may even be broken and gone.


Shattered oil control rings in the 'oily' bore.




BMWChris

Original Poster:

2,022 posts

205 months

Tuesday 20th October 2009
quotequote all
Finally managed to get head off.

Holed piston!

Bugger.