Broken Valve Spring

[Gaz64]

Originally Posted by cycleguy55

You might try using air. Make sure all the head bolts are loose or removed. Put a fitting in one of the spark plug holes in an end cylinder (not the one with the broken valve) and pressurize it. Area of a 4.36" bore is 4.75 sq inches, so 100 PSI is 475 lbs pressure pushing up on the cylinder head.

I'll say my interpretation of Brian's statement lead to some confusion.

I read it as 100 psi is 475 psi, as in 100 psi becomes 475 psi, which is impossible while you have a shop line connected to the cylinder.

100 psi would create 475 lbs of force, not pressure.

The theoretical force output of a cylinder is the usable piston area multiplied by the applied air pressure (F = PA). For example, a cylinder with a 11⁄2-in. bore and an extend force of 80 psi generates 141 lb of force (1.767 × 80 = 141).