Engine failure

[BAD942B]

Here is the piston just taken out of the Min engine, originally caused by servo failure with more damage at Goodwood Sprint mid 80s from a blown head gasket between 3 & 4, actually fully failed in 1999 on way back from Ireland. Pistons were Powermax forged ones

[Exminiman]

quick buff up with some Autosol and that will go again

[BAD942B]

[InnoCooperExport]

Forgive my ignorance, but how does a servo failing lead to this? The gasket failure however...

[timmy201]

A torn servo diaphragm could lead to a huge air leak straight into the manifold and an extreme lean condition

[InnoCooperExport]

ahh of course, didn't think of that! Thanks

[BAD942B]

brake fluid burns at twice the heat of petrol, so it must have sucking brake fluid into the manifold for a day or so, then I disconnected the servo to compete at Goodwood, the headgasket failed between 3 & 4 cylinders (at the chicane) leading to massive pinking which i could hear through the helmet, i kept my foot hard down & won the class beating Paul Chudeki in his Golf GTI in the process, the only time it came back on a trailer.
When I took the head off you could see the no.4 forged pistonwas damaged. it took a further 15 years to really crack it.
The rings came out without damaging the head or bore , it used 5 gallons of oil to drive the 200 miles back from Galway to the Midlands.