Afternoon all,

When measuring for taper in the cylinder bore can you please confirm you would expect the taper to be towards the bottom of the bore ? I.e. if the bore is tapered, the top of the bore (cylinder head end) will be wider than the bottom of the bore ?

thanks
Paul

Top will be wider than the bottom as the top is where all the wear is. There will be a limit for the engine. Should be detailed in the haynes book.

David

Cheers, thanks

Top of the bore will wear on the thrust side and the lower bore will wear on the opposite side due to the crank rotation IIRC

Interesting...

So if the top wears on thrust surface and bottom on other side do you start with a vertical bore and end up with a slanted one ?

If so and say the wear was at the same sort of rate, presumbly measurements at the top and bottom could be the same even though the bore is no longer vertical ?

How do you then measure for this eventuality ?

If and when a rebore is required the boring bar is set to be exactly at right angles to the top surface of the block whilst centralised on the unworn top of the bore , the boring tool is then set to the correct over size . Slightly simplified but covers your question .

cheers