When installing new valves into a cylinder head is it necessary to use a lapping compound and spin the valves for a few moments to help them seat or are they ok out of the box ? Is the angle of the valve job always the same as the valve ? What about on radius valve jobs ?

Also after have a valve job it is necessary to set the install height back to stock ?

 

Do not lap the valves, have a valve job done with a Serdi or better

 

if you have the money i would cut the seats

 

so when a valve job is done do they need to know the valves being used ? Wouldn't the angles on the valve affect cylinder sealing ?

 

On a radius valve job there is still a discrete 45 deg angle to match up with the valve. Unless you ordered a custom set of valves, your valves for your Honda will be cut with a 45 deg face.

 

if you drop your valves and head off with a machine shop and give them 3 angles theyll cut your seats and valves, but im assuming youre trying to avoid that and just want to throw it together. i dont think there is anyone here who can truly tell you whether or not your seats are worn out enough that they would leak.

there are ways of telling if your valves leak but they are pretty backwoods, i dont know if i even want to post them lololol

 

i am not trying to get around it but I like understanding everything that goes into it. Thanks guys.

Is lapping compound needed even after a valve job ? When I had a head done the guy who did it said not to change the positioning of the valves from where they were when I picked the head up. Why is this ?

 

there are minor differences in any machined parts. someone who knows how to do a good valve job probably won't need to lap the valves in but there is nothing wrong with it. if the seats aren't pitted I would just lap them in. one way to check how well you valves are sealing is to fill the port with warm soapy water to see if any leaks past. but i would use a really light spring to hold the valve in place, this will show if the cut is concentric to the guide. any stiff spring will surely seal up the port unless it is wayyyy off.

 

Do not lap the valves, even after a valve job.

 

Why is that ?

 

A quality valve job won't need lapping. And lapping compound will cause issues.
Read here,
http://www.theoldone.com/facility/index.htm
Like I said earlier, have a valve job done with a Serdi or better, in this case, Newen. Or ship it to Steve at CCCylinderheads for bada$$ VJ on his Newen.

 

thanks alot guys