Why I had to retire at Snetterton last races of 2006

Since the end of the racing season Stuart has stripped and inspected my race engine. If you remember i had to retire from the last two races at Snetterton at the end of the year, due to a smoking engine. As Snetterton is a long, fast circuit the engine rev`s are held higher and longer than any other circuit we have raced it, this causes a higher oil pressure than normal, the exess pressure in the MR2 engine is relived by an oil pump relif valve, which dumps the excess back to the sump. This was my problem on stripping the engine Stuart found the relif valve stuck. This would cause the excess oil to fill up the cylinder head, leading to it getting into the inlet side, causing the smoking. Stuart had intended to fully strip the engine at the end of the season this was fully rebuilt engine for this year so things needed checking, he has re-honed the cylinders to help it rev a bit more as after a season racing we have only done 680 miles on the engine, he has replaced the piston rings, main and big end bearings,he is also fitting a new cambelt and clutch plate(just to be sure i`ve had problems before and while its stripped down we gave it some xmas prezzies) so hoping for a mechanically sound year . we have also had the cylinder head apart, checked the valve seats, and springs, replaced the valve seals and reset the tappets. so all rebuilt and ready to go into my new car.....looking forward to 2007.