Lapping your own valves

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340 Dart

I don't know ****.
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Does anyone have a link to a good artical about lapping your own valves?

I have a set of "302" casting number heads I want to stick on a 318 and I want to lap my own valves in.

Thanks
 
Did ya try googleing valve lapping or get a hold of BJR racing, he does heads and must know where there's some literature. Boy it's been a couple years since I lapped some valves.

Terry
 
OK, I was avoiding this question for multiple reasons but here goes:

1: To lap valves the head of the valve must be shiny clean or the suction cup will not grip.

2: You must have a way to thoroughly clean the seat/port (safety clean tank) or the abrasive compound will destroy your engine.

3: Forget about performance as the valve/seat area and how it mates has a tremendous impact on flow.

4: If the seats can catch a fingernail on the surface pits, they need to be cut.

4: If you're still interested, you can lap using the compound found at any NAPA store. Just a drop at three or four spaces around the seat area of the valve will do.

5: Use your suction cup on a slow speed drill and go forward/reverse pulling the valve up at 5 second intervals. You'll immediately see where the problem is in the grind pattern.
 
i always use my hand just so i have more control. put the suction cup handle in ur hand and pretend to make fire lol. and make the ring of compound around the valve and the valve seal all even and just a little less then 1/4" thick so the valve has a good seat to seal aginst.
 
If the heads are used, I'd just run them. Lapping vavles in is from a time when the methods were not good enough to be that precise. A modern valve job does not need lapping as a finish step. You can in fact, make things worse by doing it. So I'd just clean the valves above the seat angles and run them.
 
You can in fact, make things worse by doing it. So I'd just clean the valves above the seat angles and run them.

Hmmmmmmmmm.:read2: There is something to think about.
 
Did ya try googleing valve lapping or get a hold of BJR racing, he does heads and must know where there's some literature. Boy it's been a couple years since I lapped some valves.

Terry

I would look in the how to rebuild small block mopars book it has alot of the info that your looking for.
 
I am looking everywhere. :read2:
Nothing beats talking to a bunch of guys who have done it though.:-D

I have "smallblock "A" engines but not the other one.

Thank you everyone for your input so far.
 
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