In the summer I posted a couple articles regarding issues that my partner was having with her R56 Cooper. In short, the engine developed a hot idle misfire which was eventually diagnosed as a loose inlet valve seat.

Prince Engine Hot Idle Misfire - Reason and Cure (IMHO)

Misfiring Mini My partner's Mini Cooper developed a hot idle misfire on cylinder 4 with a characteristic that if you disconnected one of the camshaft sensors the misfire would stop. A fault that was widely publicised but with no credible answers at that time. People's understanding of why some...
www.mini2.com

The combination of a loose valve seat and newly fitted ‘faulty Bosch plugs’ caused significant damage to the top end of the engine. Not giving up on the car I decided to rebuild the engine over the summer. The rebuild was extensive and included replacing and/or repairing many damaged components from new pistons, rings, big end bearings, cylinder head repair and in line with good practice, replacing all gaskets, seals, O-rings and TTY bolts.

On 1st August the mini was put back on the road with 125,000 miles on the clock and since then it has clocked up another 3,000 miles through daily use. In the past I would regularly add a litre of oil every couple of weeks which equated to 800 miles of use. But since replacing the ‘one piece’ factory fitted oil scraper rings with new ‘3 piece’ oil scraper rings, it has not been necessary to top up the oil.

For me this is proof that one of the main reasons for high oil consumption with the Prince engine is predominately down to the failure of the factory fitted oil scraper rings. In the case of this mini, the valve guide seals had already been replaced in 2020 with limited effect on the oil consumption; in contrast, replacing the oil scraper rings has had a dramatic effect on oil consumption.

Mini Gen 2 - Oil Consumption, Thermostat Failures And...

I have seen a lot of discussion on the topic of gen 2 mini oil consumption and excuses made by the likes of BMW that it's okey to consume a litre every 1000 miles. Well maybe it is okey for a car fitted out with a French engine, but I think the issue is deeper than that. Personally, I have had...
www.mini2.com

Several key contributors to the mini forums have been quite clear that high oil consumption with the Prince engine is due to the choice of factory fitted oil scraper rings. And for me this is now borne out by my own experience with the results of the mini engine rebuild over the summer.

I hope this helps mini owners pondering how to solve their oil consumption issues with cars fitted with the Prince engine.

 

Do you have any links to these 3 piece oil scraper rings? Or part numbers? My mother's mini has the same engine with the same problem and I'm trying to sort out these modified rings for her! She loves the car so if I could manage to help fix her issue that would be great.
3 p

 

[QUOTE=Tiarno99;4697594]Do you have any links to these 3 piece oil scraper rings? Or part numbers? My mother's mini has the same engine with the same problem and I'm trying to sort out these modified rings for her! She loves the car so if I could manage to help fix her issue that would be great.
3 p[/QUOTE
FAI Autoparts
PR12-000

Mahle plus several other companies do 3 piece rings for this engine