Is anyone still using clay to verify P/V clearance?

[cjperformance]

Clay is the only way to do it.

10-4. Clay doesn't just tell you how much, it can also tell you if the piston maker put the reliefs in the right spot... and with today's "improved" heads, the valves aren't necessarily where the piston maker might have expected them... That's not even getting into changes in the valve angles.

So true, i have clayed pistons with a large dish top and found that the typical area that a valve would contact has miles of clearance but is almost touching in one tiny area at the inside edge of the squish band. This would also have been found with the dial indicator method but would have been very difficult to pick with solder.

[steve316]

I have used lite spring method sense 2004; if I don't have the needed clearance I use clay to locate the problem area.

[geraldtson]

Plumbers putty works good for me with light coat of oil on putty and valves. Have done the spring- indicator deal before. It was something good to have learned but i don't use it anymore.

[pamotorman]

i just used a light spring and set the engine at 10 degrees BTDC with the correct lash set. i slipped feeler gauge of the thickness of the clearance i wanted between the rocker tip and valve stem tip and if the valve did not hit the piston i knew i had the clearance i wanted.

[engineguyBill]

i just used a light spring and set the engine at 10 degrees BTDC with the correct lash set. i slipped feeler gauge of the thickness of the clearance i wanted between the rocker tip and valve stem tip and if the valve did not hit the piston i knew i had the clearance i wanted.

When using the light spring/dial indicator/degree wheel method, the measurements should be checked at several locations at least 20 degrees BEFORE and 20 degrees AFTER TDC in order to get valid results. A lot happens in this area as the valves are chasing the piston . . . . . . .

[Momus]

I run 5mm valve stems....I think solder would tweak the valves....looking at them wrong seems to tweak the valves.

So clay after everything checked good with and a dail indicator and degree wheel.

I build small engines with necked valve stems that are 3.50 and 4.00 mm titanium. No way I'd use solder there, though I do use it for squish.

I've used polyester body filler that sets after the turnover to make measuring more accurate. Touching surfaces need to ne oiled.

[Stan Weiss]

David Vizard's PowerTec 10 EP 20 Power enhancing valve pockets

https://www.youtube.com/watch?v=y6WEAPsmCvE

Stan

[PRH]

I only use clay for verifying radial clearance in the valve pocket.

For “vertical” clearance I use checking springs and an indicator, and check the clearance every couple of degrees thru the overlap period to zero in on where, and how much minimum clearance there is.