Advanced Engineering Tech - valve guides

dose a iron valve guide wear better or less than a bronze valve guide when using a stock ls rocker arm?

this isn't really asking the right question. But iron is harder then bronze so should wear less, in genral like your asking.

Now will both last a long time, setup with the right valvetrain geomety? Or can both get destroyed really fast if setup wrong?

if the valve train geomety is set up right.

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...

i heard that if you have a roller tipped rocker arm then you want a bronze valve guide.

I think you mean if you have bronze guides you need roller rockers.

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...

there is no friction really...the valves dont ride on the guide...

there is no friction really...the valves dont ride on the guide...

Then why do the guides wear out over time? Natural break down? lol

Then why do the guides wear out over time? Natural break down? lol

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.

less!!!!!!!!

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.

Yeah, friction is much more a function of surface finish, proper geometry and proper oiling than it is material.

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.