408 hyd roller, too much spring pressure?

cookietruck said

DANG, comment from one of those threads...
look what a single change to the components did.

"We were experiencing valve float at 6500 rpm with 11/32 valve, 1.94/1.54 with CC beehive set up at 160#/394#, titanium retainers, Smith Brother's push rods, Harland Sharp roller rocker arms, tool steel lifters. Went to 5/16" valves, and increased rpm to 7100, but still nose dives. Going to dual springs next to see where the problem is. Joe-JDC"

Click to expand...

Yes, but if you read the follow-up comments by Mike Jones, Vizard and others there should have been more still to come.

David Vizard
"Joe,
The current CC 26918 spring is currently about my favorite street or street strip or basic C/track spring. Never had a failure since day one. Have now accumulated what must amount to several thousand hours total run time. There may still be some to learn here but my experience is to set them up so that only the top about 1-1/2 coils are short of coil bind.

Sometimes this results in seat pre-loads higher than might be needed but the spring performs best (as indicated by dyno figs) when it is run close to total coil bind."

Beehive spring performance ? - Don Terrill’s Speed-Talk

I did the same with my beehives – higher seat loads but better spring damping. In fact, Manley specifically suggests running as close to .050" coil bind as you can and not to go over .100" with their beehives for optimal results. If you've even seen the way coils wobble on a spintron, you'll understand why.