valve guides
#4
Reason they are Bronze is because they wear before your expensive valves like a bushing. You can replace them with iron but the coefficient of friction is higher, more wear...
#9
12 Second Club
iTrader: (49)
lack of lubrication, carbon build up inside of them taking the oil cushion away. you usually have about .002 of oil clearence in the valve guides. about the same as a bearing.
i didnt really mean there is no friction, what i ment to say was the difference in materials between bronze and steel guides is not going to create less or more friction.
i didnt really mean there is no friction, what i ment to say was the difference in materials between bronze and steel guides is not going to create less or more friction.
#11
TECH Addict
iTrader: (4)
lack of lubrication, carbon build up inside of them taking the oil cushion away. you usually have about .002 of oil clearence in the valve guides. about the same as a bearing.
i didnt really mean there is no friction, what i ment to say was the difference in materials between bronze and steel guides is not going to create less or more friction.
i didnt really mean there is no friction, what i ment to say was the difference in materials between bronze and steel guides is not going to create less or more friction.
They wear over time due to the geometry not being perfect, or the surface finish/stem shape/guide shape having flaws that result in metal-metal contact despite the oil film.