Valve spring shimming

[Stevex]

I'm going to be sending my LM2 heads for refurb this winter. New valves, springs and collets and guides K lined with seats re cut.
Am I right in believing the outer valve spring length when refitted needs shimming to obtain a length of 36.7mm - 37mm?
How is an easy way to measure this accurately?

[lucky phil]

I'm going to be sending my LM2 heads for refurb this winter. New valves, springs and collets and guides K lined with seats re cut.
Am I right in believing the outer valve spring length when refitted needs shimming to obtain a length of 36.7mm - 37mm?
How is an easy way to measure this accurately?

Install the valve in the head without the spring and seat the retainer and collets after installing a spring shim on the head. Hold the valve closed and use a 6" caliper to measure between the spring shim and the spring seating face on the spring retainer then calculate the additional shims/s you will need of preferably a single thicker/thinner shim.

Ciao   

[Stevex]

👍Thanks. Les, that's  one pristine head you've got there.

[Antietam Classic Cycle]

Install the valve in the head without the spring and seat the retainer and collets after installing a spring shim on the head. Hold the valve closed and use a 6" caliper to measure between the spring shim and the spring seating face on the spring retainer then calculate the additional shims/s you will need of preferably a single thicker/thinner shim.

Ciao

This ^^^