Sqrl4runner87

I had to lap in some new valves and this is my first lapping. I just did this one and it's still a lil crusty. Do I lap again or leave it??

millball

Lapping valves with hand methods is an old school rite of passage best reserved for lawn mower engines and Model T Fords.

If you want any long service out of your machine, get the valve seats machine cut and the valves machine ground with correct angles and face widths.

The seat in your image is NOT good enough.

Co_94_PU

iTrader: (-1)

You need to keep going until it has a solid seat 360°..

The multi angle valve grind shows in the image above. Compare the factory section, where the carbon still shows in the image, to the section that has been polished down notice the sharp edge about a quarter of the way through? This is the multi angle..

As stated above it is best to have them done at a machine shop, but again if you want a decent deal you need to keep going.

Co_94_PU

iTrader: (-1)

You should research the "four angle valve grind".. But here is a crappy phone edit..
90° flat, blue
45° angle, black
60° angle, red
75° angle, yellow

Again research.. It's a crappy quick image