I received a set of new valve springs yesterday. They are supposed to register 24-28 pounds when compressed to 2 1/8". They don't. They register at 20 lbs or less. I tried them on two different scales and compared them with a used set that registered 24 lbs. I had the same trouble with clutch springs a year ago. Come on, how tough is it to make a good spring?
I am not sure how tough it is to make a goo spring, but if it was my car & I had exhausted all other choices I would use the old ones & keep my fingers crossed.
Edward R. Levy
It isn't all that tough to do, especially if any kind of quality assurance measures are used which they obviously aren't.
That being said, those springs that you have will probably work just fine as long as they don't weaken much over time AND you provide plenty of valve stem to bore clearance, especially on the four exhausts.
I just went through all this and found an inner spring out of a set of performance big block che? springs.It has a free length of about 2 1/4'.I am using 1.5' small block che? exhaust valves with modern retainers and locks.The installed height works out at 1.95' with 35-40lbs on the seat and 60lbs open.I am using a stipe 280 cam and bronze cam gear,but I dont think the spring pressure would be to high for standard parts.The springs i used are Crow cams brand down in victoria 'Aust'. They cost me $50 for 8 springs.Being a good quality spring they wont go soft.You would be able to get similar springs (and probably cheaper in the USA) through any engine rebuilding shop or cam supplier.
Hope this info is usefull. Lindsay..