piston face

[Mingish]

im just wondering why does the top of a piston look the way it does?
whats the purpose of the dents?
im thinking maybe something to do with increasing surface area to reduce heat..i have no idea tho

[CivicSpoon]

To clear the valves better?

[Kven]

Originally Posted by CivicSpoon

To clear the valves better?

its so the valves dont hit the piston.

[crxlvr]

yes that is correct. this type of motor is called an interference engine, meaning if the grooves were not in the piston, the valves would slap into them at every upstroke. a non-interference engine is just the opposite.

[5gcivic]

yeah to prevent piston to valve clearance problems, some are more severe than others and those are usually pop up pistons for more compression