grinding you own valve seats

tastyklair · #1 (**permalink**) 02-25-2004, 05:01 PM

I'mm Looking at doing my own valve job. The guides are good and actually the seats and valves aren't bad, but I'm porting the heads and will probably need to reface the seats afterward. I have an inexpensive kit available. Anybody ever do their own? Any thoughts?

Capone · #2 (**permalink**) 02-25-2004, 05:11 PM

One word for you.....

Concentricity.....

oh and did you cut back the rear face of the valve heads? this can also aid in flow....(it is kind of like giving your valve heads a 3 angle valve job on the port side of the valve)

tastyklair · #3 (**permalink**) 02-25-2004, 05:30 PM

I looked that big word up so I know what it means, but what are you trying to say?

Ecuri · #4 (**permalink**) 02-25-2004, 06:20 PM

You can hand lap them. Look it up in your Clymer or whatever. It is practically free. Put some varsol down the ports overnight and see it they leak.
He is trying to say the valves should seal in whatever location they land. Two( or more) perfect circles, the seat and the valve face. GL

tomw · #5 (**permalink**) 02-26-2004, 08:15 AM

If you lap the valves, make sure to keep them in the same cylinder. Pull or push the valve about 1/4" up from the seat, and try to rock the valve around. If you get much motion, your valve guides may be too loose. Lapping using compound you can get valves to seat so that you have a shiny surface in the valve and seat that is the same width all the way around the valve. If you do not get an even 'shiny', then the valve is not matching with the valve seat... as noted in the fancy word, concentric.

tom

beartracks · #6 (**permalink**) 02-26-2004, 10:14 AM

If you polish the chambers you can drop a couple of old valves in there while you do it to protect the seats. If too much damage is done to the seat the might require inserts to correct it.