New cams from Tick Performance
I've tried tracking this pattern of "valve-train" noise from cam lobe to different cam lobe, and push rod length to different push rod length, and just when I think I've found a set of lobes that are quieter than another set, a customer pops up with the "quieter" set-up that is just as loud as the ones that were louder in other set-ups.
I know for a FACT my PR length and preload is spot on, and mine sounds like 8 Singer sewing machines being ran at a pants factory in China. But I don't mind, at all. I'm very well aware of the ramp rates of the cam I have. It's actually the valves opening and closing, not rocker arms or PR's.

I know for a FACT my PR length and preload is spot on, and mine sounds like 8 Singer sewing machines being ran at a pants factory in China. But I don't mind, at all. I'm very well aware of the ramp rates of the cam I have. It's actually the valves opening and closing, not rocker arms or PR's.

Bumper cam GoPro Hero 3 test - YouTube
I know for a FACT my PR length and preload is spot on, and mine sounds like 8 Singer sewing machines being ran at a pants factory in China. But I don't mind, at all. I'm very well aware of the ramp rates of the cam I have. It's actually the valves opening and closing, not rocker arms or PR's.
I've been talking to some valve-train manufacturers and valve-train parts distributors lately about lifters and have been hearing some very interesting and also some very disturbing things. Hopefully I will get some time and the opportunity to test the things I've been hearing about one day to verify for myself firsthand.
The Best V8 Stories One Small Block at Time
This also isn't just pertaining to one brand or type of lifter as well. The case where the plunger had become stuck all the way in the bottom of the lifter bore was with a high dollar aftermarket lifter!
It seems that with aggressive cam profiles and high spring pressure the lifters begin to collapse at higher engine speeds which causes a loss of valve lift, and with too little spring pressure the lifters pump up which casues the valves to over extend and not open/close when they should causing valve float and/or a loss of power.
Looking for ways to remedy this situation are endless and there are a few quick and easy ways to stop it from happening like use of milder lobes, less spring pressure and correct pre-load for performance and not so much for what is the quietest. With some of the vendors on this board recommending ever increasing aggressiveness in lobe profiles(LSK/XER) and then pushing ever stiffer springs to control them, collapsing a lifter becomes more and more of an issue and the resulting loss of valve lift that goes along with it.
Seems counter productive to me which is why I find myself trying to use less aggressive lobe profiles with my cams, less pressure from the springs I use and I've even found myself pushing aftermarket lifters more and more where as I use to be very found of stock lifters such as the LS7 lifters. Do LS7 lifters still have their place and can you make great power with them along with run great track times? Yes! I went 6.30's cam-only with stock LS1 lifters that had never been replaced!
That said if you're looking for every last bit of power, you'll run an aftermarket lifter.
seems like you need a lifter with progressive leakage rate to compensate for changes in oil pressure - something that bleeds less at lower speeds to prevent collapsing while bleeding more at higher rpm to prevent pump up.
no idea if anything I said holds water but it's interesting stuff to me, nonetheless. trying to learn some stuff.
Last edited by ckpitt55; Mar 17, 2013 at 05:06 PM.







