Too close are

[1972ho]

Not hitting the piston but is this just to close

[Newold1]

Yep, :I would agree! Too Close!

[ProPower engines]

Yup that is touching but only a couple thou.
Can you or do you have any need to advance the cam a couple degrees if that is an exhaust valve touching??
That will give you more room maybe about .050-.070 depending on the cam you have.But that will still be close but good enough without missing a shift.

[Dutchman]

Take .030 off the valve face and call it perfect. If the margin allows it

[1972ho]

This is a intake valve and it’s already 4 degrees advance I’ve been thinking of having the valves ground down about .020.

[statsystems]

This is a intake valve and it’s already 4 degrees advance I’ve been thinking of having the valves ground down about .020.

Do it like Dutchman said and take it off the face of the valve. It wont change the stem height.

[englertracing]

Send piston to Erik at rebco

[Dave Koehler]

This is a intake valve and it’s already 4 degrees advance I’ve been thinking of having the valves ground down about .020.

Do it like Dutchman said and take it off the face of the valve. It wont change the stem height.

I think you meant geometry or pushrod length. Stem height and valve spring height will change as well as chamber volume IF it is super printed. Otherwise, no drama

[1972ho]

Can’t the bottom side of the valve be ground/cut to decrease the margin so that the valve doesn’t move further into the head seat like facing the seat of the valve .I have new titanium intake valves with thick margins.

[Dave Koehler]

Ahh, was that what you guys wanted to cut? The chamber side of the valve?

[statsystems]

Ahh, was that what you guys wanted to cut? The chamber side of the valve?

Yes, chamber side of the valve.

[Krooser]

Have reliefs cut into the piston

[Dave Koehler]

At this point it probably isn't feasible for the OP to cut pistons. Maybe at tear down time.
Actually we don't know if this was a missed gear or a superstocker running on the edge.
We don't know if this is just a one valve problem or all 8.

FWIW I consider the valve face to be the side that contacts the seat.

[Newold1]

You could cut the valve face back depending on margin thickness but you should go back tot he valve rep. or manufacturer and let them tell you if you can take the amount you would like to off the face without WEAKENING the valve. Also from you pic it looks as though the edge of the valve is getting to close to the relief edge and that would not increase any clearance from cutting the face. Not knowing how hard and what rpms you are putting this valve train to, its hard to know how close to danger you are. If you are racing hard and revving above 6500 rpms you should keep that clearance at a minimum of .060" in my opinion. This is exactly why these clearances should be determined with clay on any engine such as this before its assembled for the first time. The piston top being clean and the head gasket looking unused would indicate this engine is in final assembly without being run. My advise is, its out, it can be broken down and the pistons and that relief can be cut easily and issue is over. Bite the bullet and do it right the first time!

[Blakeslee]

If you use a slightly thicker head gasket wouldn't that take care of the clearance issue without machining?