What Is A Valve Job?

[SpyOneUSN]

can someone explain to me what exactly a 4 or 5 angle valve job is and what benefits it does? im guessin it has to do wit air and fuel flow. is it worth the money if your building top end? how much do they run if it is?

 

[viciousracing]

the angle job is the angle the valve seats on the cylinder head chamber. it's usually modified to produce good air/fuel flow efficiency.

 

[SpyOneUSN]

so is 4 better than 3? im guessin more angles equals better shit

 

[viciousracing]

what they mean by 4 and 3 is the "DEGREE" they want to shave off the valve seating to modify air/fuel flow.
from what i know but not sure, most b series sit on a 44* angle, and the valve face angle measures out of a 45* angle, a one degree difference. by shaving "4 or 3" degrees off, means shaving the valve seat "4 to 3" degrees out. So the stock angle of 44* would change out to 47 or 48 degrees depending on what you have shaved off. but the valve face angle has to be shaved out to be 1 degree higher than the valve seat. (be sure you have enough valve margin)

 

[saturn_boy96]

hey this is what i was told by my machinist. a three anlge valve job takes the usual one andgle on the valve and vale seat and cuts in two new ones- "3 angles". the purpose is to allow smoother air flow.

i drew a pic, i know its retarded.

 

[saturn_boy96]

by the way i heard that almost all hondas already have a mild 3 angle job from the factory.

 

[ekPhred]

yes, i also heard that from the factory they put a 3 angle job on it as well.

 

[machine]

Originally posted by saturn_boy96@Mar 20 2003, 12:18 PM
hey this is what i was told by my machinist. a three anlge valve job takes the usual one andgle on the valve and vale seat and cuts in two new ones- "3 angles". the purpose is to allow smoother air flow.

i drew a pic, i know its retarded.

i do believe hes got it!

 

[EF9]

Does the valves need to machine to match the v.job??

 

[saturn_boy96]

usually the valves have the same angles cut into them and then they are "lapped" to the valve seat. lapping allows a total seal in the combustion chamber.

 

[SpyOneUSN]

nice arrows on the picture!

 

[saturn_boy96]

my question is, did it do the job?

 

[93tegh22]

how dus it help you when u get a v.job

 

[viciousracing]

SATURN BOY----> it is not lapped to the same degree, the seat is 44 degrees while the valve is 45 degrees, it has a 1 degree difference.

 

[saturn_boy96]

who told you that, i just want to know for my own knowledge. have you lapped vales before? i don't think the difference could be measured.