Valve Head Depth Below Cylinder Head Face

[Martingo]

Can anyone confirm the valve head depth below cylinder head face on 2L TD engine.

According to my manual the minimums are 0.9mm inlet and 1.3mm exhaust. Problem I have is that the values I’ve measure are well below this but it doesn’t seem to have caused any issues.

cheers

[robert1]

Hello, Inlet 0.90 to 1.24mm Exhaust 1.30 to 1.64mm.
The after market valves I have used had so much margin that I had to have them refaced so them would meet this, are your valves new or old?

[Martingo]

Yes those are the values in my manual.

the valves are old but in nice condition. I seem to have the opposite problem because the measurements are averaging 0.6 inlet and 1.0 exhaust. I can only assume the head has been skimmed way too much in the past. Obviously with this situation the risk is the valves and pistons start getting very close or contact but who knows how close they really are or what effect it has. Of course I could lap the seatings down to get to spec but 0.3mm is quite bit to remove if not really necessary.

Cheers

[robert1]

No you have the same problem, can you post a photo of the side of the valves?

[Martingo]

Pic attached, inlet on left

I think I understand what you mean, so the after market valves are heavier so you get smaller gap to the cylinder face. I do think my situation is skimming though as the head depth is below the 120mm

cheers

[Martingo]

[Doctordiesel77]

Early pistons had a recess under the valves in the crown, later ones didn't, I'd be more concerned about the valve protrusion on an engine without the recess. Might be worth checking clearances with piston at tdc, if there is a reasonable gap without relying on the thickness of the gasket, then you should be safe.

[robert1]

Skimming will not of helped, but because of the angle of the valve seat the valve will recede a lot for little wear, I think you have enough margin to have the valves resurfaced

[Martingo]

Top of the pistons have a big pocket but the valves go beyond that to the flat top.

I decided it was best to get the valves down to the minimum so I’ve been lapping all day. Some weren’t that far off and some took long time.

[Doctordiesel77]

Top of the pistons have a big pocket but the valves go beyond that to the flat top.

I decided it was best to get the valves down to the minimum so I’ve been lapping all day. Some weren’t that far off and some took long time.

Those are the later pistons, so I think you are doing the right thing there, not sure why they did away with the valve recess...