Time to come clean.

So. Engine reassembled, runs ok, oil cooler bursts.

Engine doesn’t run ok any more. 60psi oil pressure at idle, which drops linearly to 20psi at 4500rpm. There’s some kind of rattle. The oil, which was new 14km ago, looks like Deepwater Horizon had a glitter rave.

Out it comes again.

Here’s the damage:

Those bearings are toast. One, in particular, but the others aren’t looking too flash either.

We took all the bits to Henry at Auckland Camshafts, who consults as an engine failure analyst when not creating bespoke cams. His diagnosis: The obvious bearing failure is probably due to oil pressure loss, but started by particulate damage throughout the engine (almost like the engine block wasn’t cleaned properly before assembly. D’oh). The cam had been damaged, piston rings overly worn, and the whole lot is full of bearing shrapnel.

So here we are: the block is off at the engine reconditioners again to have the bores honed ready for new rings, and hopefully the crank can be saved with a polish. The cam has been reground (fairly severe damage) and the followers lightly refaced. Gaskets, bearings etc. are en route from Minispares in the UK.

Might not make it to the Mini Nationals this year.