So how do you check piston to valve clearance

86T-Top

Founding Member
Jun 29, 2001
553
0
17
Dublin, PA
Like the title says. I have a good idea on how to do it but a few questions.
- What do I use, is play doh cool? If not what can I use.
- How much do I put in there to start? Just lay it over the valve reliefs?
- Finally how much clearance do I need?

Combo - 351W, flat top pistons with valve reliefs, AFR 185 heads, lift is .523"
with 1.6 rockers.

Think I will have a problem with this cam and head?

Mario
 
play-doh will work fine, just a loonie sized blob should work
put it on the piston, where the valve would hit, then turn over the engine and see how far it presses in

don't know how much clearance you need, but as long as it never touches I asusme that would be fine? (feel free to correct me on this)
 
sirr0bin said:
play-doh will work fine, just a loonie sized blob should work
put it on the piston, where the valve would hit, then turn over the engine and see how far it presses in

don't know how much clearance you need, but as long as it never touches I asusme that would be fine? (feel free to correct me on this)


It should touch the clay. You rotate the engine through the intake/exhaust strokes with the clay on the piston, and the head mounted (use your head gasket also so you get proper measurments)

After this, remove the squished clay and measue its thickness to find your PVC.

.100 clearence for the exhaust valves and .080 for the intake valves is the most common PVC unless you are planning on reving to 6500+