I'm Aussie and I agree it's odd but it's an old school industry standard. Bore and stroke generally measured in mm but clearances/interferences etc. generally given in inches. Never really thought about it until you mentioned it but it would be confusing for someone from outside. We haven't always been metric and a lot of people, myself included, were taught both systems.JadusMotorcycleParts said:Anyone know why an Australian guy/company uses inches for bore measurement? Then mm for measurement?
Its because of the finer increments of 1/1000 inch than 1/100mm i think, but what do i know, im a welder! those measurements are too fine for me..Pete12 said:I'm Aussie and I agree it's odd but it's an old school industry standard. Bore and stroke generally measured in mm but clearances/interferences etc. generally given in inches. Never really thought about it until you mentioned it but it would be confusing for someone from outside. We haven't always been metric and a lot of people, myself included, were taught both systems.
datadavid said:Its because of the finer increments of 1/1000 inch than 1/100mm
Tell the british that! they promised they will convert to metric though. Inch by inch!der_nanno said:1/1000" is actually 2.54x 1/100mm, so it's in fact 2.54 times less accurate ;-)
(But we're officially splitting fractions of hairs... ;D )
datadavid said:Its because of the finer increments of 1/1000 inch than 1/100mm i think, but what do i know, im a welder! those measurements are too fine for me..
Did you bother to read what i wrote?hooligan998 said:1/1000" = .001"
1/100mm = 0.000393701"
Which is finer?
JadusMotorcycleParts said:0.035 - 0.055mm. Is this good?
datadavid said:Did you bother to read what i wrote?
It was a bit of a joke. Been using both imperial and metric for 15 years so no need to try and lecture. Thanks.hooligan998 said:I had to read? WTF is this?
JadusMotorcycleParts said:Yepp, Special Piston Services came back with a recommended spec: 'CLEARANCE = .0032” @ 23 MM BELOW OIL CONTROL RING you could perhaps try slightly less maybe .0025 min'
Anyone know why an Australian guy/company uses inches for bore measurement? Then mm for measurement position? .0032” = .08128mm, .0025" = 0.0635mm
themotoworks said:if australia is anything like I learned from mad max …
stroker crazy said:Mad Max is actually a documentary!
Crazy
der_nanno said:I've had another good long thought on the subject... It really depends on the bore and material of your piston. Is the new one forged as well or is it cast? If it's forged, you definitely have to go up with the tolerances and gutt-feeling tells me, around the 0.07mm to 0.08mm clearance is roughly 1/100 of the bore or one percent differential expansion due to dissimilar materials of piston and cylinder/liner in the hottest area of the piston and should be alright for a forged piston. If it actually is a cast piston, going below one percent will prolong piston life dramatically and aiming for the higher end of the range will probably just do you fine. Maybe being a bit more gentle on the first hundred kilometres might be advisable anyhow.
Cheers,
Greg
stroker crazy said:Mad Max is actually a documentary!
Crazy