Grinding valve stems.....who does there own and how?

[Mr. 856 170]

Im assuming some of you take on the task yourselves. I am curious as to how you do it? I know there are special tools for this purpose but I also know some of the brave do this with tools most of us already have laying around. Is it that hard to do? is it worth paying a guy to do it? I have a set that needs doing.......don't mine taking on these kinds of tasks if its within my means.

[rmaynard 14,970]

Doing it on your own, unless you have the proper equipment, can be difficult. I took my block and the valves to my local machine shop that did my cylinder hone job, and they did it for me for free.

[sorekiwi 761]

Are you talking about refacing the seat area on the valves?  or just shortening the other end of the stem to get the correct valve clearance?

 

Refacing the seat area is usually done on a valve refacing machine that grinds the seat true.  They can also be done in a lathe, either way a machine shop is required.

 

Grinding the end of the valve stem to provide valve to tappet clearance (for example on the small block Kohlers) can be done at home on a bench grinder.  Care must be taken to gind the stem square.  I clamp a V block to the rest next to the grinding wheel, and use the side of the wheel.  Take very small cuts and check the clearance often, one the gap is too big its time to buy a new valve.

 

An old valve refacing machine waiting for me to get around to a bit of refurbishment:

 

[buckrancher 2,678]

I do my own on a spin grinder at work

[Mr. 856 170]

yes I was talking about the valve stem itself. so the idea is to have the stem in some device and easily put the side of the grinding blade to stem to take material off?

[sorekiwi 761]

The important thing is to grind the end of the valve perfectly square.  That's why I set up a V block to rest the valve stem in at exactly 90 degrees to the wheel, and use the side of the grinding wheel to do it. 

[SousaKerry 500]

Just be careful grinding on the side of the wheel, unless you have a cup stone you may wind up with shrapnel in your face.  I've seen the aftermath of such an incident and it wasn't pretty...

[VinsRJ 721]

To grind the valve stem end... I just free-hand them on a bench grinder... so far no issues...

[Coadster32 793]

Just be careful grinding on the side of the wheel, unless you have a cup stone you may wind up with shrapnel in your face.  I've seen the aftermath of such an incident and it wasn't pretty...

 

Good advice.    I "ring" my wheels before using.                      (If your wheel has a crack, which most likely will be catastrophic, it won't "ping" it will "thud" when you try to lightly ring it like a bell)

 

Mike you might consider after dressing the wheel, to grind the valve end from the wheel diameter in, using the face of the wheel and not the side. Much safer, and it was designed that way.

 

If you grind the end too far, you might be able to save it by re-lapping the valve to seat in the block, suction cup style. You should be grinding off very little at a time, so fixing it should be in the same ballpark.

[sorekiwi 761]

Just be careful grinding on the side of the wheel, unless you have a cup stone you may wind up with shrapnel in your face.  I've seen the aftermath of such an incident and it wasn't pretty...

 

This is very true and generally it is bad practice to grind on the side of the wheel.  However in this case you are ususally only taking off a few thousanths, and using a very light touch on the wheel, so I feel comfortable doing it. 

 

Perhaps I shouldn't publicly recommend anyone else do the same though.