guys
I am currently having the barrel of my M20 Bored to suit a 0,040" oversize piston when I reported to the machinist the recommended clearance on the Web Site of Between 0.004" and 0.006" he Thought this was A bit Wide and you Would hear the Piston Slap for Some Distance is this the correct clearance and where on the piston is it measured?
Regards
email (option): grumpy.moran@gmail.com
Hi Ron, Piston clearance is measured on the piston skirt at the front and rear of the piston (the thrust faces when the crank is rotating). .004"-.006" is the correct clearance and will run without problems.
I generally get them honed to the minimum figure and 'run in' carefully.
It is frequently the case that machine shops more familiar with modern engines think the clearances are excessive..and that includes the valve guides.
However, tighten them up at your peril...I have experimented and they don't like it!
My local engine shop man also can't get his head around a 4.9-1 compression ratio and is convinced it should be at least 8-1..
...Ian
email (option): julie@wright52.plus.com
Ian
Thankyou again for the QUALITY information the Machinist always does Qualty work but his Bread and Butter are Mainly Modern Watercooled Engines but we will educate hin as we Go as an aside without putting Pressure on how are the Early Patten Bash Plates Crankcase Shields What ever you like to call Them Coming
regards
Ron Moran
email (option): grumpy.moran@gmail.com
I've mailed you direct Ron...Ian
email (option): julie@wright52.plus.com
Hi Ian,
Can you also tell me when you think the sump-plates are availeble?
Cheers,
Leon
email (option): ljvbekkum@hotmail.com
can i have one as well please ian?