The problems never end

[Roger Goldthorpe]

Not the same situation but I ran a two stroke with an alloy cylinder with chrome plated bore. The cylinder bore was deliberately pitted to retain oil for lubrication.

Roger

[Ivor Hawkins]

I rebuilt a three bearing motor and the bores were pitted, I carefully honed the bores and the pits were still clearly visible from the top to the bottom of every bore, the car went very well, the exhaust was clean and it burnt very little oil.

As the gouges are well below where the rings work their hardest, I’d be tempted to check the gudgeon pin and rings, pop the piston back in and run it.

[Renaud]

Thanks for the thorough answers.
That engine is a Rosengart less common than Austin so that enters the equation!
I counted 3.5 "against" for 1.5 "for". (I counted you half for and against Alan).
I believe when time comes I will see how the compressions stands.
I don't know how Renault pistons availability is now.
Thanks again.

[12jslater]

THE CARS CURSED 

Took the head off, sump off with no issues, popped the piston out, turns out the clamping bolt was fine, the damage to the cylinders must be from from years ago, so a waste of time, the piston then decided it wanted to pop its lower ring bellow the bore when I was under the car, the piston then got wedged and upon removing the bottom oil ring is now broken... This car will give me grey hairs far too soon haha

[charlie carpenter]

What size of pistons are they as I have a selection of rings and I am happy to send you one.

Charlie

[Howard Wright]

 Also check to see if the grooves are new or old.  If they appear old they may have been present before the last engine rebuild.

Cheers

Howard

Hate to say it but.....guess it is difficult to judge if scores are new or old and probably I would have erred on the side of caution and taken the piston out   .

Good luck
Howard

[12jslater]

They're big seven rings and oversized 0.060"  so that limits my spares hugely.

[Jeff Taylor]

Have you tried Robin Taylor (no relation !) of the Austin Big 7 Register and Spares - email: robin.e.taylor@talktalk.net

There's also an "Austin Big Seven" private group page on Facebook with 449 members.

https://www.facebook.com/groups/1534369470108586

Also worth contacting F. W. Thornton

https://www.fwthornton.co.uk/piston-ring-sets-l

[charlie carpenter]

Sorry can help with +40 but not +60. I am sure Robin Taylor can help you he is a Big 7 Stalward.

Charlie

[Bob Culver]

When at age 20 and less I was first running my Seven as everyday transport I rather looked forward to non calamatous problems as an excuse to tinker with the dear wee mechamism.....
A mechanic colleague is seriously afflicted with an interest in cars. He has bought, renovated to varying degress and evntually resold a succession of 1930s to 1960s cars. Nearly all had significant assembly errors or obvious faults detracting markeldy from correct function. I am always very sceptical of the comparison test done by old car mags. Never sure how original or defective cars are.