How things used to be, no Vincent content.

[John Cone]

On the subject of micrometers, until recently i still had a full set of internal mics which i had given as gift when i stated my apprenticeship as an engine builder in the 60's. Theres no need for them today because as bores get worn we just pull out the liner and insert a new one and keep everything as standard. With most large truck engines it does not matter what the physical size of the engine is ie: 240 to 680hp the bore sizes are the same, the power out puts altered by remapping the engine management system, altering the valve timing or the fuel injection system. So theres no need to rebore or worry about oversize pistons.

 

[Alan J]

My old "heap" is about to be treated to a rebore and new pistons-40 thou oversize-did 70,000 miles on the last pistons, will I manage another 70,000 miles and need new liners? Only time will tell! I did mention that pistons used to be 50 quid, now only 85 quid!! a bargain! thanks to "club spares!"- Kettering is great for me, a nice ride through the lanes of Northamptonshire- Hope to see Ian Savage back "on duty" soon! Alan J. p.s off to "the Dragon" soon!!

 

[Tom Gaynor]

At 70,000 miles I'd expect the liners to be little more than a light push fit in the muffs, which it is widely accepted lose their grip with age. Yes, quite. It would be worth your while therefore to check the fit of the liner in the muff before making your decision. It ought to be 0.006 interference.
(A friend decided that he needed a new liner in his Comet. The guy who was going to fit it put the Comet barrel on the table, and started to light the gas axe to heat the muff to make sure it was necessary. Before he struck the match there was a "clonk" as the muff slid off the liner. It was necessary. Gravitational anomalies were not suspected. )