I'm currently replacing a valve on a B16A2 head. At first I replaced the valve and it still failed the brake cleaner test. I took the valve back out and swapped out the springs for some GSR Valve springs that I had, it still leaked. Now I'm thinking that the valve seat isn't flush. Has anyone ever used a valve lapper and valve lapping compound. I searched but there isn't any information so it's got me to thinking that it might not be what you are supposed to do on honda heads. I don't really get how a valve lapper works so if you have any pictures or an explanation it would help a ton. Thanks

 

I bet you could find a valve lapping stick at Autozone or Pepboys. I know you can get 120 and 280grit lapping compound at Pepboys.

If you can't find a lapping stick at a local store, you can order one from Goodson, Northern Tools, or just about any other online tool store. Get the small one. The exhaust valve is 28mm in diameter I think, so don't get one with a suction cup bigger than that.

I'd imagine that the procedure is pretty self-explanatory.

 

thanks for the info man we'll see if i can find what i need

 

yeah i've done it and it will take like 10min on a valve if you use corse then fine grit, small suction cups for the tool and if you can find one get a locking one (sucks all the air out so it always sticks) it's hard to find info on, i know there is a miata site out there that has a pictorial guide on how to do it, Google for Hukuna Miata

 

all right ill check that out

 

valve lapping is fun

 

Be fully aware that regardless of how well you clean the lapped surfaces of the seat and valve face, compound will continue to be imbedded, causing premature erosion and leaking valves in no time. Lapping valves is a good "fix" if you're just trying to get a car running well enough to sell (and you don't care when it goes to pot on the new owner), but it's a bad practice if you're keeping the vehicle.
You have to machine both the faces of the valves and the seats to create a seal that's going to last.
The face of the valve will become concave in shape (rather than flat) after lapping. When the engine's at operating temperature, the valve will expand more than the seat in the head, so the now convave surface of the valve won't seal on the portion of the seat it was lapped, or mated to.
I've been doing preparing valve seats and valves for more than 35 years, and lapping is a bad deal, unless you're looking for a temporary seal....

 

I agree completely with Larry,a good valve seal is one of the most important factors in a well running engine. A valve job isn't that expensive considering the power gain usually seen from a good one.

 

That info is invaluable.

Well....guess I won't be ordering that super sucker 3000 valve lapping tool I always wanted.