I’m rebuilding a 93 sporty. I tore down the engine and had it vapor blasted. It was a horrible mess after probably 18 years sitting in a barn. Engine looks great now but I knew that the valves would need to be lapped. The seats are smooth. The intake valves honestly don’t look bad. The exhaust valves had carbon and pitting. I cleaned them up with some scotch brite but they still looked a bit nasty. I can take the heads in for a valve job as a last resort but I wanted to give this a go.

I hand ground this exhaust vale. I can see that I’ve got a decent band going on the middle angle but there is still pitting visible. Am I on the right path and just need to keep going? Is this valve shot? What do wiser eyes see?

thanks! ✌️

 

Take the heads in to have a professional perform a valve job. That valve is pitted and has a ridge around the seated area, most likely from your hand grinding. The valve guides need to be checked for wear, as well as the valve stems. Then the seats cut to the proper width and angle.

 

1. I see that you should buy new valves and lap them in if the valve seats are in good condition.
2. If the valve seats are in similar condition, get new valve seats also.
3. Best bet is to take the heads and get a valve job along with checking the valve guides, springs, etc. and let the shop determine if you need new valves or not.

NOTE:
The above information, while credible, is worth what you paid for it and should not be considered gospel.
Do due diligence, research and have a H-D Field Service Manual before working on your bike.
You will probably have many opinions and suggestions presented; make sure you research the person providing the helpful information as there are some who provide good information that is useful and some who speak out of other orifices with gibberish. You will figure out this quickly.

 

Thanks for the feedback. Where did I go wrong? I felt like my hand grinding wasn’t going to be such an impact since I had just started. The seats are smooth and don’t have any pitting. I honestly would have the uneducated opinion that the valves were in decent shape so I feel like I took this from something that I could have done to something I can’t.

 

I don't think you did anything wrong. That valve just needs more than you can do with lapping compound. A local machine shop advertises $101 per head on a valve job for Harleys. We all have budgets so do the best you can.

 

As Ohio HD said, nothing you did, looks like the pitting was already there.

Need to clean all the carbon and crap off the valve before any lapping is accomplished.

Let a professional with the proper tools & equipment do the job, you will be $$ ahead and not have to do it over in 5K miles when you do not have proper compression etc.




See valve below and compare. See the difference?

 

Before any work on the valve seat or valve face can happen, the guides need to be check for wear. They become oversize and tapered over time, that allows the valves to rock slightly, as well the valve stem wears similarly and adds to the misfit of the valve face to the valve seat. Lapping worn valve faces and valve seats is a short lived solution even if the guides are in good shape. And if there is significant wear to the valve guides, your efforts are not going to solve anything. The valve will rock and effect seating and pressure loss.

I assumed that when stating it's being rebuilt, you want to have it back to new specifications.

 

If not new, then in spec for reliable riding.

here’s a picture of the seat for the exhaust valve. I’m not sure if the photo is able to give a clear view of the shape it’s in. The intake valves were clean as clean can be. The exhaust valves were gummed up. I didn’t take a wire wheel to them so I probably started in on them earlier than I should have.

thanks for the feedback ✌️

 

Why not have the valves reground and the seats recut?

 

It don't look too bad..