Ede SBM RPM head springs, the ones that come on the heads for flat tappet cams, test at
[email protected],
[email protected],
[email protected]...... which is pretty much right on with what the specs are.
For solid cam use, it would have to be a pretty mild set of lobes for me to not swap the springs.
I usually shim them up to 130 on the seat for most applications where I feel the spring is adequate.
I don’t recall the open pressures exactly on the SM heads........ but I remember thinking it was barely adequate for the XE268 cam that was going to be used with those heads.
Something like 250-275 open.
They were in the 115-120lb on the seat range.
The spring had a pretty low rate, but lots of travel, so plenty of room to shim them up.
For solid cams with that type of head I use a Crane 99893, or one of the equivalents offered by some other companies.