Lockdown lowdown :(

[makeitfit]

How do muckers
With all this down time I've been enjoying sorting my mega list of things to do around the house, absolutely loving it, skint as a church mouse , but loving it.
Any roadup it came to pass that the Black Pearl was needing an engine rebuild again
Last year after less than a 1000 miles the old lump literally spat it's oil out big time. Oil blow by was horrendous.
I did a comp test and true enough the wet test was double the dry. Suspected piston ring failure.
Sooo, here I am again with the engine completely stripped down.
On strip down everything seemed ok till I looked carefully at the bores. They looked quite marked like from the rings but the biggest thing was the ring gaps that should be 25thou, are now 4.26mm



Here's a view or two of the bores.


All the pistons seem ok but here's a pic for your delectaton :thumbs

It's been suggested the hone I had done was rather course and had no cross hatching, combined with suspect quality rings :nenau
I'm off to an engine specialist tomorrow to check the bore sizes for tolerance etc.
Wish me luck :lol

 

[macabethiel]

I've been there did that !

Back in 1978 when I was well skint I rebuilt a 1275 Cooper S engine that had been bored out plus 30 thou of an inch.

I used a rotary glaze breaker in my drill to score the bores as I had fitted new piston rings. Engine rebuilt and it would not start. After a couple of days making sure the distributor drive shaft was in right and checking the timing, the spark,dwell I resorted to a tow start. It fired up immediately. I drove it a couple of miles, it was well fast with a new 731 BL Special Tuning Camshaft duplex timing gears etc.

Got home had a coffee went to start it again and she fired up - result !

After standing overnight it would not start again unless tow started - yep I had messed up the compression with my glaze breaker.

Engine out again and rebored to maximum - lesson learnt - glaze breaker in bin!

 

[solarman216]

Yes honing is supposed to be very mild with a supper fine grit, too course and you might as well call it a re-bore but without quality control, Rick

 

[makeitfit]

Yes honing is supposed to be very mild with a supper fine grit, too course and you might as well call it a re-bore but without quality control, Rick

If only I knew that when I built the bugger
Anyway, I took it in today for professional advise, and luckily, the bore is still within Nissan spec.
Therefore , it's going for cross hatch hone, deck check and the head surface ground.
Again, that had been done with a single point milling machine, leaving marks in the head gasket
Fingers crossed next week I get to build it all over again .
Any recommendations on piston rings while I'm here ? :thumbs