A valve grinding tool for #4 exhaust?

[Sculldog1]

7 of 8 valves and seats lapped and ready to go back in! However, the #4 exhaust valve was badly pitted and I ordered new one. Question is is there a tool or grinding stone I might be able to use to create an acceptable surface on the seat as it is pretty rough? I will be lapping the new valve into the seat but thought that if I could use another tool to do some of the initial work it might go faster and give a better result.

[Surcouf]

I would say the old valve: might be pitted and not re-usable, but should be a good "lapping tool"

[Sculldog1]

I did try that but the top was quite badly pitted and the suction cup thing wouldn't stick to it making it ineffective. I was beat from lapping the first 7 valves and called it quits at that point. I may try to tack weld a bolt to the valve so I can chuck it into cordless drill and have at it that way. I did see 45* grinding stone but not sure if this would damage seat to the point of ruining it and forcing me to pull the motor. Would need .3145 mandrel I suppose but not sure if it is prudent considering I am trying to avoid engine take out and haul out. Any thoughts from machinist types appreciated. Thanks

[Dave Neptune]

Valve seat "cutters" are available easy to use and usually available for rent. I have used them of many engines.

Dave Neptune

[Al Schober]

Using a valve as a lapping tool is OK, but it's not going to remove much metal. You really need something more aggressive, such as the stone in the photo.

Last engine I did, I had the shop do the valves and seats. Intake seats weren't too bad and ground in. The exhaust seats were shot and the shop installed carbide inserts - no extra charge.

I like Goodson for engine tools! www.goodson.com

[Sculldog1]

Slick idea to fix pitted valve seat

So as the summer of discontent plods forward I had to find a way to fix up badly pitted valve seat. After some research I stumbled on a video by a young man who cut 3 very small bits of 100 grit sand paper and crazy glued them to the 45 degree part of his old valve stem and then used it to dress up the seat. I tried it and after about 10 minutes had a nice result. Lapped the new valve with coarse and finally fine paste and it looks as good as new. Might help someone save an engine removal. Cheers