I tried to use some online convertors, but have no idea what the hell I'm converting... any help would be appreciated. If you would like to elaborate on the unit of measure, that would help on any future conversions that I do. The reason I'm doing this is because I'm trying to compare the specs between Jun and ferrea valvetrains for the B18C heads

Jun b16/b18 valve springs specifications are as follows. It says unit: mm, kgm.
Diam. 3.7 2.5
set leng. 34.0 30.0
lift leng. 22.0 18.0
set load 23.0
lift load 84.9

Ferrea specs (There are several, so how to do the conversion would really help, but here is one of them):
O.D.---- 22.8 ---- 30.25 mm
I.D. ---- 17.2 ---- 22.8 mm
Seat press. 100 lbs @ 34 mm
Open Press. 220 lbs @ 24 mm
Rate Inch-------- 305 lbs
Coil Bind--------- 20 mm
Max Net Lift----- 13.5 mm

 

JUN valve springs
Seat pressure at 1.339" (34.0mm) spring installed height:
50.706 lb

Pressure at .866" spring height (1.339" - .866" = .473" lift [12.0mm lift]:
187.172 lb

Spring rate:
(187.172lb - 50.706lb)/(1.339" - .866") = 288.5lb/in [assuming a linear spring rate]

Ferrea S10027 Dual Spring
Seat pressure at 1.339" (34.0mm) spring installed height:
100 lb

Pressure at .945" spring height (1.339" - .945" = .394" lift [10.1mm lift]):
220 lb

Spring rate:
(220lb - 100lb)/(1.339" - .945") = 305lb/in

Is that any easier to read?

I don't know what the second set of numbers are for "set leng." and "lift leng.". EX or innersprings maybe? Altho, I thought JUN springs were the same for both sides, so they must mean inner spring spring heights when they refer to, "set leng." and "lift leng."

The seat pressure varies according to the spring's installed height. I'm not sure if there's already an easy way to measure the installed spring height since the only install height micrometers available are too big to be used in Honda heads.

100lb's at the seat on the Ferrea's is a bit much, don't you think? Maybe you should look into Ferrea Endurance S10070 springs with the accompanying retainers, and seat locators. You do know that you have to use Ferrea's retainers and seat locators in order to use their springs, don't you?

 

Thanks for the great info. That ferrea model valve spring isn't necessarily the model... I'm still awaiting info from the seller regarding which model is actually in the head. I was just reseaching what ferrea offers so I can convert them when I receive word.

Again, thanks for breaking that down for me.