Valve Spring Differences

[Rodney Racer]

OK all you experts out there. Help Me Out Here.. I have a fresh fresh fresh 59AB. Done up by a "well-known" flathead builder. Runs terrible at idle. Passes compression test, has an NOS bone stock cam. Vacuum Gauge Needle bounces like crazy at idle. SO--- I pulled intake, checked valve adjustment, right on the money, loosened them up a couple thou. just to see what I would get.. Runs about the same.. Pulled heads and valves --- But in checking valve spring pressure---- Sure did seem VERY WEAK--- So I checked out two of the OTHER engines I have here.. One has a big cam and springs, yep, they have some real GOOD pressure.. The other has a spring with a larger wire diameter that what is in this stocker. I REALLY SUSPECT these "stock" springs are just to weak. But they are "new" --- Anyone care to express an opinion here?

The picture shows the spring I have in question on the left. The one in the middle is MUCH stronger and the one on the right is used with the Big Cam