Daytona-Dave

The engine was still running just had a knock Tom knew it was terminal so didn't run it so as to try and save the block

Daytona-Dave

Toms old engine, engine started knocking so it was shut down and swapped for a known good one, the problem turned out to be No2

Toms1989

Interesting stuff mate. How heavy is the scoring on the crank? Doesn't look bad but pictures tell a thousand lies ha

Nick Graves

Indeed; it's difficult to tell from the photos, but that looks like a really lucky escape.

Looks like aside from crank scoring damage done by spinning the bearing, it's really very light.

Nottm_S2

so is that just a bearing failure? (excuse the ignorance)

Nick Graves

From the dirty mating surfaces of the big end cap, plus the damage to the piston, it looks more like the cap came loose, causing the bearing to get hammered and spin.

It could be that a failed bearing hammered the bolts loose, but that seems unlikely, it they were correctly-torqued and the thread speed is sufficiently fine. I know it's not aviation grade thread, but it would seem strange for Honda to make a basic error like that.

Daytona-Dave

what caused the bearing failure that is a different matter

Daytona-Dave

Just checked the ring tolerance's from Tom's engine with the Honda manual and the top ring is well within spec in every dimension the 2nd ring is within spec but towards the service limit but the oil control rings were that far out of spec they almost fell through the bore when trying to measure the ring gap so the car would have had very good compression and good leak down test but would have supped copious amounts of oil

CHIPPO

Would the mind betting my oil rings are kerfurgled , it drinks oil , at or about the infamous 1 litre per thousand miles.

One day I might find out.!

Daytona-Dave

These are the two bolts that were loose from the worn bearing you can see the shinny threads where they had being chattering around




And these are two bolts from a good rod end