Piston Clearance
Posted: Mon Jul 11, 2005 8:33 am
Just checked the diameter of the bores in my twink and I think I have discovered why I have so much piston slap. The bores are too big.
Before I come to any final conclusions can someone please tell me what the correct clearance is between piston and bore wall. I have heard mention both 2 and 4 thou.
Measuring my piston at right angles to the gudgeon pin about 1/2 inch from the bottom of the skirt, I get 3.267" The bore is measuring 3.274" which seems a bit big to me. All the bores measure the same and they are dead parallel - no wear.
I think the pistons are +20 and are solid skirt.
The engine was rebuilt not long before I got the car 15,000 mls ago. looks like the rebore chappy was a bit too enthusiastic!
Any advice welcomed.
Regards,
Hamish.
Before I come to any final conclusions can someone please tell me what the correct clearance is between piston and bore wall. I have heard mention both 2 and 4 thou.
Measuring my piston at right angles to the gudgeon pin about 1/2 inch from the bottom of the skirt, I get 3.267" The bore is measuring 3.274" which seems a bit big to me. All the bores measure the same and they are dead parallel - no wear.
I think the pistons are +20 and are solid skirt.
The engine was rebuilt not long before I got the car 15,000 mls ago. looks like the rebore chappy was a bit too enthusiastic!
Any advice welcomed.
Regards,
Hamish.