What is the maximum amount of cylinder taper normally allowed?

What is the maximum amount of cylinder taper normally allowed?

• A. 0.02 inch
• B. 0.06 inch
• C. 0.10 inch
• D. 0.04 inch

Answer: (B)

Cylinder taper is the difference in bore diameter from the top of the cylinder to the bottom due to wear. To determine it, measure the bore with a dial bore gauge at the top and again near the bottom (and at a couple of depths) and compare the two diameters. The limit you’ll commonly see for acceptable wear is about 0.06 inch. If the taper exceeds this, the bore is out of spec and usually needs re-boring or sleeving, with oversize pistons to restore proper compression and ring seal. A smaller value like 0.02 or 0.04 inch would indicate tighter wear limits and isn’t the standard maximum you’d tolerate; 0.10 inch would be excessive and indicate the cylinder is too worn.

Cylinder taper is the difference in bore diameter from the top of the cylinder to the bottom due to wear. To determine it, measure the bore with a dial bore gauge at the top and again near the bottom (and at a couple of depths) and compare the two diameters. The limit you’ll commonly see for acceptable wear is about 0.06 inch. If the taper exceeds this, the bore is out of spec and usually needs re-boring or sleeving, with oversize pistons to restore proper compression and ring seal. A smaller value like 0.02 or 0.04 inch would indicate tighter wear limits and isn’t the standard maximum you’d tolerate; 0.10 inch would be excessive and indicate the cylinder is too worn.