Hello, John Talley here with partzilla.com.
Today I'm going to show you the process-- it's called lapping your valves.
So whenever you're having to rebuild the head or you're replacing the valves, this is going
to be a necessary part of it to make sure that the surfaces line up correctly.
You only need a few tools and the head itself, so let me go grab those and I'll show you
how to get it done.
Alright basically there's only one type of tool you'll need to get this little project
done.
It's a lapping tool that actually has a rubber cup on the end of it, so that'll basically
hold it in place where you can run it back and forth.
The other piece you're going to need is a valve grinding or lapping compound.
You can pick it up at most any local auto parts store.
Third thing, you need to pick up a little tube of Prussian Blue.
I like to check what progress I've made by actually marking the edge of the valve with
ink and it actually will transfer to the valve or from the valve onto the seat.
Other than that that's really all you'll need to get this done.
Now chances are this is going to be really simple.
Everything should line up fairly well and have a nice groove in there.
What we're going to do is coat one of these before it's been lapped with Prussian Blue.
And what's that?
It's a type of dye that actually shows you where metal's making contact.
So, let's take one of our exhaust and we're just going to lightly coat it.
Go ahead and pop it in, and then we'll be able to see where all it's hitting.
Alright, one of two ways you can do this.
Either use one of these little I guess you'd call it lapping tools that actually attach
to the valve on this side via suction cup, or just a quarter-inch piece of fuel line.
Just slide it over the valve stem on the other side and then just turn it back and forth
a few times.
Alright, let's pop her out.
Alright, we're looking for a consistent blue impression all the way around roughly the
width of this tip of this pick tool.
And that is pretty much exactly what we're looking at.
That actually looks really good, so it's not going to take hardly any lapping at all to
get this in there correctly.
So, let's get that cleaned back off and then we'll start the lapping process.
Grab our valve.
It doesn't take a lot of this stuff.
this is basically just an abrasive in a grease base if you want to call it that.
Alright, and now that we're going to be putting a little bit of pressure on the stem itself,
let's go ahead and put a little bit of oil on it.
The last thing I want to do is scar that surface.
Now you want to be very careful as you're doing this not to let any of that material
get on the valve stem.
That would be bad.
Now when we start this off it's going to sound kind of gritty and that's okay, that's what
we want.
But as I go further and further, it pushes more of that out of the way and it'll start,
you know, you won't hear it as much.
See how it goes away?
Now, just lift it up a little bit.
Get some more of that material drawn back in.
Just like that.
Alright, just going to pull her out.
And that should take care of it.
Now we want to make very sure that we clean out all of that material because that would
be catastrophic to say the least.
Typically, on one that is as close as this is, four to five times, starting at the beginning,
wait for it to be quiet, that about all it's going to take.
Just for fun, we'll put the Prussian Blue back on there again and take one more peek.
Oh yeah.
Nice blue line all the way around.
That one's ready to go.
Now, all I gotta do is to the same thing for all the other ones.
Now am I going to go back and check it with the Prussian Blue again?
No, probably not.
It's just going to take a little bit of lapping compound, about four or five times with either
this tool or that rubber hose, and then we'll start actually installing the valves once
that's done.
Alright guys, that pretty much wraps it up.
Well listen, if you need a new set of valves for your machine come see us at partzilla.com
and we can get you taken care of.
If you have any questions or comments just leave them in the section below and I'll do
my best to answer them.
And until next time we just want to say thanks for watching.