Is it necesary to have the head machined (3 angle valve job) when installing aftermarket valves? I have installed regular oem valves and just used the normal lapping process. It worked just fine. Is there a difference in the angle of the valves that would force me to do this?

 

Anyone?

 

It is not a "have to" but rather a "should'.

 

Did to perform a leak test to see if the valves made a perfect seal?

 

No I have not yet. I guess the more I have thought about it....the more the Should factor as combustion contraption pointed out, comes to mind. But just for information purposes....are the angles on the after market valves...such as ferrea or supertech different than oem. I couldnt Imagine they would be, but have you ever noticed this...or heard of it? Thanks for the input.

 

You need to clarify what youre talking about. Are you referring to the seating angle? The 45? Or are you referring to back cut angles just above the 45 for improved flow?

The seating angle (45) is the same on all the valves, OEM or aftermarket. Back cuts vary by manufacturer, OEM does not have a back cut.

 

Best to get the valves "refaced/ground." They have rounout and pitting on high mileage engines.

Good valve grinding machines are Sunnen VFR 7000 centerless grinder - awesome results wid dis macheen meng. The Kwik-Way SVS-II is also good.

<FONT SIZE="5">KNOWLEDGE FO DA WIN!!</FONT>

 

Machine Shop ****

http://www.youtube.com/watch?v=k557Zoeu38s

 

Is it reccomended to lap the valves after a valve job?

 

Depends what kind of equipment was used to perform the VJ.

 

I was reffering to the back cut's...I should have been more specific. Thanks for the great information. I think I am just going to spend the extra $$$ and send it to Portflow. I would really like to learn how to do it myself....but I dont think It would be worth it to buy all of the equipement when I am probably not going to use it enough to make it pay off.