jackhammer

Is this valve job ok?

The pictures are exhaust valve before and after lapping. Every valve is in exactly the same place. seems to me the seat should be a little wider and be centered more on the valve. (??)

BillK

JH,
The width looks ok, but I would have centered it on the valve a little better. It should be about .080" wide. It probably wont hurt anything other than performance. Also, why do all the work on those heads and then leave a nasty little "step" in the exhaust port to mess the flow all up ? I would pull all the valves and spend a little time with a die grinder to smooth things out some right below the seat. Bet the intakes are the same way.

By the way, be careful with the lapping compound, you can do more harm than good. It needs to be very fine, just enough to "mark" the valve. I think the stuff we use at the shop is 320 grit.

Also, Try cleaning the seat real good then color it up with a magic marker. Then lap the valve in and see if it is hitting the seat all the way around. Tells you how good a job they did with concentricity.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

jackhammer

Thanks for the input Bill...

I was too scared to put my grinder back in there. Problem I have is not knowing when to quit! Should I only knock the step down?

I used fine compound. It doesn't say what grit it is. I would guess about 10 seconds of 20 degree twists.

I'll try the magic marker test. but I tell ya... with a clean seat and valve it feels like there's a suction fit (sticking together)

jackhammer

Here's the intake... I'm not too proud of the bowl work. I think I was getting lazy. I purposefully left it rough (60 grit) but didn't remember it being that lumpy.