While I have the Fronty R head off, I'm replacing the valves with new big block Chevy valves and guides. I know I'm weaker, but the springs seem a lot more stiff than they need to be for an engine I rarely spin over 4,000 rpm. Add to that the 3:2 lifter ratio, and that has to be hard on the cam.
What would be a good spring force?
What is it now and what is the installed spring height? Lift ratio doesn't factor in. The spring is to close the valve. You need more than stock to close those big Chebby valves. Especially at higher rpms.
Free height = 2.3"
Installed = 2"
~.015 wire, OD 1.375
I'm thinking of the load on the cam compared to stock springs and 1:1 lift. I don't want to be worried about lack of ZDDP. . .
Yeh, the valves are big: 1.875" intake and exhaust, so they almost kiss in the middle of the chamber. That also means a set of BBC exhaust valves will do for the whole head.
Those "retainers" look suspiciously like "Rotocaps" or "Rotocoils". Are you running positive rotation devices?
60 pounds when compressed on your set-up, not on the bench
Out of my new springs I get 42lbs at an installed height of 2". Sold my extra set last year. If interested I can get you the name and number of who has new ones. J
Would the camshaft break from flexing?
No, The problem with unnecessary strong valve springs would be the extra wear on the cam lobes from the lifters. Maybe ZDDP in the oil would be more important with an overhead setup, otherwise usually not needed in a standard T.