I am almost finished in doing a complete engine rebuild on my race motor nc30 after a big end failure. i have been very careful in rebuilding this motor and have checked all clearances etc with a replacement crank and rods and shells etc and have taken my time to get it right but there is one final problem which i cant find any info about in the manual and on the net.
On the right side of the lower crankcase below the crank shaft there is a small metal disk, i presume it is some sort of oil pressure release valve as it sits in the end of one of the oil gallery's, if it is should i be able to remove it easily or is it pressed in at the factory and designed to be left alone.
I have been careful but have tried to move the disk but it is stuck fast, i just dont want to rebuild the engine and have a release valve stuck, if anyone could shed any light on this it would be greatly appreciated.


Many thanks ian

I think you will find that if you consult the factory service manual on this website, it indicates that the pressure relief valve is located adjacent to the oil pump and the small metal disc you refer to is simply a end plug for the oil gallery.

I know there is a pressure relief valve that push fits into the lower crank case but just wanted to make sure there wasn't another on the end of the oil gallery suppose thats why its not shown on the schematics.
Thanks for the heads up just wanted to be sure i hadn't missed anything.

Thanks again

There is no apparent escape path around the small metal plug if it was a relief valve.