Valve Lapping?

[uwntsumrtII]

Hey all, im gonna be doing a lapping job on my heads. And im replacing the valves with new ones.

Do I need to do the lap job with the old valves or the new ones?

 

[uwntsumrtII]

Safe to assume I should use the new valves? That way the head and valve is lapped evenly?

 

[Sean]

typically you lap new valves in. Not a fun job. did you get a qoute on a VJ ? usually fiarly reasonable.

 

[dave89iroc]

lap the new valves

 

[uwntsumrtII]

typically you lap new valves in. Not a fun job. did you get a qoute on a VJ ? usually fiarly reasonable.

Its a matter of time right now. I can't wait a couple weeks. So im just going to lap them for now.

Thanks guys

 

[DarkoStoj]

well isnt the purpose of lapping them to make sure you have a good seal? If you lap a set together and then change them the seal wont be right im assuming

 

[347convert]

take a small piece of rubber tubing maybe 12" long... Make sure it fits over the stem of the valve snug.

Then find a drill bit to cram into the other end of the tubing.

Chuck the drill bit into a drill.

Put lapping compound on the valves and install them.

Slide the rubber hose onto the valve stem, once secure apply light pressure to the valve face and spin the valve with the drill.

It takes a little practice, but you will get the speed correct.

 

[uwntsumrtII]

take a small piece of rubber tubing maybe 12" long... Make sure it fits over the stem of the valve snug.

Then find a drill bit to cram into the other end of the tubing.

Chuck the drill bit into a drill.

Put lapping compound on the valves and install them.

Slide the rubber hose onto the valve stem, once secure apply light pressure to the valve face and spin the valve with the drill.

It takes a little practice, but you will get the speed correct.

Great idea on the rubber hose. I was gonna us a drill. But I was worried it would damage the stem.

 

[cjmatt]

how much do you really need to lap them? ive always used the suction cup method

 

[dave89iroc]

how much do you really need to lap them? ive always used the suction cup method

suction cup works fine, but tiring after 16 valves

 

[1BADAIR]

find good lapping compound. not the road gravel that most parts stores sell

 

[fastredgmc]

why are u replacing the valves? what are the heads or head off of?
lapping only works if the seats are in decent shape. If they are resessed or pitted it will never work.

PM me if u want. i work in a machine shop and can do a proper valve job on your heads. i can have them back to you within a couple days

 

[Sean]

Its a matter of time right now. I can't wait a couple weeks. So im just going to lap them for now.

Thanks guys

I can get a valve job back in a day.

 

[uwntsumrtII]

how much do you really need to lap them? ive always used the suction cup method

Not a hole lot. I did a leakdown test and I have some air seeping past the valves. Test came out with some good numbers. I just want to clean them up a bit while the heads are stripped down.

 

[uwntsumrtII]

why are u replacing the valves? what are the heads or head off of?
lapping only works if the seats are in decent shape. If they are resessed or pitted it will never work.

PM me if u want. i work in a machine shop and can do a proper valve job on your heads. i can have them back to you within a couple days

Now I just ran out of cash :-(

They are Mopar R/T Heads with the 2.02 intake and 1.625 exhaust. Leak down test showed good numbers. I just wanted to clean up the seats. My dumb ass broke one of the valves so I just decided to replace them all. They ain't cheap LOL.