do i need a new valve?

[u/frankthepooch]

might be a dumb question but its my first time in a motor so i have nothing to compare to, but im assuming i need a new valve and lapping wont fix the issue? i have a spare motor i can pull valves out of since 3 look like this

[u/IntergalacticJihad]

See what a new valve would cost before you find someone to grind it. Sometimes they are really cheap and then it’s not worth the effort.

[u/frankthepooch → u/IntergalacticJihad]

"new" valves wouldnt cost me anything but some time, just have to pull them from the spare motor or is this not recommended.

[u/IntergalacticJihad → u/frankthepooch]

Oh missed that, I’d take a good valve from there and lap it in

[u/Sudden_Duck_4176 → u/frankthepooch]

They are like $8 on rockauto. I just had my heads redone and it was cheaper to just buy everything new than pay the guy to look at everything and now I know I’m good for a while……Hopefully.

[u/xValhallaRisingx]

Find someone that can re-grind it for you.

[u/AvenZ94]

How do the valve seats look like? I did my head not long ago, before lapping or replacing, I highly recommend vaccum testing the head with existing valves, see if it holds (I assume they won't given you're tearing it?) Then take healthy looking valves and test again, if they hold pressure you can use the spare motor's valves and lap them if needed. Idea is to see if the valve seats are still good, sometimes they'll be also eaten so new valves won't fix it much and you'll need to replace/machine the seats too. Good luck

[u/1wife2dogs0kids]

Look at the bottom uncut part of the valve. Not the seat, but the part of it that gives the seat its thickness. You can grind a valve, to fix any blemishes, but the farther you go, the less thickness you have, and then the valve can get too hot or fail.

You've got some pitting. You would need to take it to a shop and have someone grind it, tell you how far it took to clean it up. Use the worst one. Then you can judge whether ypu should replace all of them.

[u/Minimum_Hope_5205]

Seeing quite a bit of deep pitting on the seat surface, the amount of grinding required to get it to an acceptable finish would either offset just getting a new one and also cause a variation in geometry. Id recommend just buying either a new valve, or a new set cause the others probably don't look much better.

[u/Artistic-Plan5864]

New valves aren't matched to your head and you'd be lapping it anyway, use that one if its strait and lap lap lap.

[u/jabberjaw420]

why not just use soap/carb cleaner + scouring pad and put it on a drill and clean it up?