How tight is too tight? piston to valve clearances

[GOT-Torque]

How much clearance should you leave?

How small can you go and still feel comfortable that the piston and valve won't meet?

 

[Timebomb]

.080-.100

 

[COMP461]

on a street motor .050 , is fine , on a race engine with good springs and parts then you can get the intake as tight as .030 .

be sure to check at 15 , 10 , 5 and 0 BTDC and 5 10 and 15 ATDC .
the piston is chasing the exhaust shut , and the intake is chasing the piston down

 

[SSpeeDEMONSS]

i went .008 intake and .018 exhaust and no problems. though im far from the level that most guys on here are at.

Garrett

 

[matty169]

P to V or valve adjustment setting?????

i went .008 intake and .018 exhaust and no problems. though im far from the level that most guys on here are at.

Garrett

OP is talking p to v, and I think you are talking about adjusting valves. Not the same.

 

[malibu795]

on a street motor .050 , is fine , on a race engine with good springs and parts then you can get the intake as tight as .030 .

be sure to check at 15 , 10 , 5 and 0 BTDC and 5 10 and 15 ATDC .
the piston is chasing the exhaust shut , and the intake is chasing the piston down

and or mic your mains rods wrist pin clearances that will give the distance moved from oil clearance... not to include rod stretch or piston strech at the end of the exhuast stroke. cant rememeber general rule of thumb on rod strech ... manufactor should know that number

 

[GOT-Torque]

Thanks Comp, I actually found in one of your older threads where you listed those same numbers. I've got good parts in it but as it sits, it's too tight on the exhaust. As soon as my different cam keys show up I'm going to try and gain some room.

I'm checking from -10 to 10 in 1 degree increments.

Did you get my PM about some pushrods?