[chuckies76ta]

Ok, Thanks to all the info. I appreciate all the help. I just want to make sure I'm not missing anything.. I want to list things involved in setting springs up. Not in order of course..
Installed height.
Seat pressure.
Open pressure.
Coil bind.
Clearance under Rocker to retainer.
Clearance to Valve seal.
Clearance if spring sits in cup or locators.
Checking each springs for height, coil bind, straightness and pressures..
Inspect each spring for any visual defects.
Inspect locks. making sure 10deg on 10 deg valve stems or if using 7 degree.
The type of lock whether square or bead lock.
Using hardened shims.
Choosing +.050, standard or -.050 locks.
Retainers that fit the springs. Retainers can have built in +or _ .050
Doing a heat cycle on new springs.
Compressing new springs to coil bind before checking.
Checking valve spring tester with a calibration spring to test equipment for accuracy.
Make sure to always test spring for pressures with retainer that will be used, and to deduct retainer thickness for true coil height.
Make sure the retainer is not forced onto spring.

Missing anything?

Thanks

[gtofreek]

Originally Posted by chuckies76ta

Ok, so can you shed some light on this scenario. What changes because of the solid lifter? other than it's a solid lifter.

Thank you

A hydraulic lifter, when working correctly, acts as a shock absorber to maintain zero lash so the lifter is always in contact with the lobe. This "shock absorber" is also the limiting factor as to how much spring pressure can be run. But since it is designed to maintain zero lash, and there is no lash, it doesn't need as much pressure anyway. Also, hydraulic lobes are designed for this "shock absorber" so the ramp rates are such that the lifter doesn't have issues following it with the pressures called out for HR cams.

Now, when you put solid lifters on a hydraulic cam you change the way it was all designed to work together. You no longer have a "shock absorber" to maintain zero lash so the lifter is always in contact with the lobe. Now you have lash, even though it's tight lash, it's still lash so if you don't have enough spring pressure to control and keep the lifter on the lobe bad things can start happening real fast. The HR lobe was not designed for a solid lifter. When I asked Harold Brookshire about this, he thought is was a completely crazy thing to do and saw no reason to be doing it. He said even though a solid roller lobe has lash, it still generally has more area under the curve and would perform better than a hybrid setup.

Hope I explained this in a way that makes sense. Sometimes it's hard to put these things into words, and I don't always find the right words to use.

Running a little too little spring pressure on a roller cam does far more damage than running a little too much pressure. Running less pressure doesn't free up HP either. Whenever you have one valve opening against spring pressure, you have another one forcing it's spring pressure down on the closing side of the ramp to balance things out. You can have an engine with 1000 lbs. of open pressure and the completely assembled engine won't take hardly any more torque to turn over than an engine with 300 Lbs. open pressure. So there really is no benefit to running less spring pressure as long as you are not way over springing it to begin with.

[chuckies76ta]

Thank you Paul. I appreciate you taking the time to explain this. Also, Thanks to all of you who provided feedback.

I understand Paul, putting thoughts down through a keyboard is not always the easiest.

I understand what your talking about with spring pressure and ramp profile and keeping the roller lifter on the cam. That's probably why the lash should be keep at tight as possible. like .004

Thanks again

[Steve C.]

" I don't go out of my way to recommend people run solid roller lifters on hyd. roller cams, in fact less than 5% of the hyd. roller cams we sell end up with solid roller lifters on them, my personal preference is to run hyd. roller lifters. "
Dave Bisschop


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