It takes a lot more spring pressure to make a hydraulic lifter collapse than what you think. You can run 200 lbs seat and 450 lbs open on them without issue as long as you have quality lifters and oil flow to back them up. I run consistent 160-170 lb spring pressures with 400 lb open pressures on my engines with the real big valves and valvetrain components...2.300" valves, 10" long pushrods, linkbar lifters, etc, etc.
You can tell when valvetrain control goes to pot. It takes a while to get a particular combination nailed down, and sometimes it takes valve spring changes, preload iterations, etc., but once you have it nailed it's easy to reproduce and use that info for other engines.
For a ~6000 rpm engine, I think a hydraulic roller is absolute perfection. No maintenance, no break-in, no drama.
I have never used a BT dual plane Cleveland intake before, so I have no experience to draw from with them. The runners were already closely matched to the gasket and a small notch was cut out of the divider. I think maybe extending the notch through the whole length of the divider may have helped our tapered spacer issue...but who's to say.
B2 Motorsports, LLC
This message has been edited by blykins from IP address 18.104.22.168 on Jan 28, 2012 7:07 AM This message has been edited by blykins from IP address 22.214.171.124 on Jan 28, 2012 5:44 AM