Originally Posted by 14 apache

I would like to know the spring in reference to the chart. Has to be percentage of loss on the big picture. My springs are around 250# the will not loose what that chart said per temperature.

Originally Posted by MILD THUNDER

I have heard that Carson Brummet, has had nothing but issues with hydraulics, morels, johnsons, didnt matter. Turbo motors he builds don't get alot of duration, but they had alot of lift (for a hydraulic setup). After suffering too many issues, he has since gone back to solids, and the issues have went away from my understanding. With every product, there are design limitations. You can't use a screwdriver, to pry open a safe. You'll just break the screwdriver. Same goes for camshafts. If there werent design limitations, we wouldn't need big body lifters, 60mm cams. Valve lift makes power in a big block chevy. If there were no limitations, why aren't I running a .750 lift .842 lifter'd 236 duration hydraulic cam, instead of a .630 lift cam?

Theres just so many variables. Hydraulics, while have came a long way, are still not solids. A 730 lift long duration cam in a 632ci , might live a long time at 7500rpm. Cam a 454 with duration levels to suit 6000rpm, and 730 lift, and a hydraulic lifter, it might last 5 minutes. Also what works in a drag car, or boat, that isn't sitting there at 6000+ rpm for several minutes at a time, is quite different than what happens when its there for a second at a time making a pass.

I have a question. Lets say you have a combo on the dyno, and you are running say, 10-40 engine oil. Say the oil temp is 160 degrees on the dyno, and you begin the pull at 3500, and pull an engine to 6500, doing a sweep run. The oil is fairly viscous at that temperature, and some valvetrain stability issues, may not show up with as much intensity, or even be existant, as you are sweeping thru the rpm levels at a very quick time.

Now, what happens when you are out on the water, and you are in your 41 apache. Your tachs are steady at 6300rpm, you oil temp is getting up to say, 230 degrees, and getting quite thin. The oil inside the lifter, is possibly capable of bleeding out easier now? Things start getting weird, slack forms in the valvetrain, still on the throttles holding it WFO, not letting off. Stuff starts losing control. Spring pressures are going down, as the coils are heating up big time. Lifter starts lofting slightly off the lobe, more slack in the valvetrain....valves start bouncing off their seats, valves now lose seat time to transfer heat do to valve bounce, valves get really hot...Still on the throttles WFO....

Is there possibly any relation to the concept, of oil temperature and lifter bleed down rate/viscosity, and possible loss of valvetrain control, from temperature of the valve spring, causing a reduction in spring pressure?

According to this PAC spring chart, you are losing around 40-60 lbs of open pressure, when comparing the spring at room temperature, to 250-300 degress. I certainly wouldn't think, that if you have oil temp at 220-230, that the spring is running COOLER than the temp of the oil being sprayed on them.

Is this something you might see on the dyno? I don't know. My guess is its not something you can determine from a computer when designing a valvetrain from scratch. I'd like to think this is where cam companies spend time with spintron testing, whether a cam is going in a marine/endurance engine, or a bracket car, what spring pressures are needed to control the setup, when is too much, when is too little, what is stable, what isnt, and so on. Seems like no matter what product, what theory, what design, is ultimately considered a success, is when it actually lives in the field it has been designed to do so. We can make excuses all day long, but at the end of the day, if its failed, it simply isn't a success.

GPM, as you stated "Once we got the right lifter,spring pressure, pushrod and rocker, we didn't have any problems" , is a great statement. The question is, what happened BEFORE you found the right lifter, the right spring pressure, pushrod, and rocker? I'm assuming, not good things. Most guys here, are paying for someone to provide them with the right recipe. If they have had failures, than it wasn't the right recipe, and finding it is the key. However, the real problem lies in the issue that if the guy you paid, won't work with you to find that right recipe after the fact, then , the whole project is a failure.

What I have found as a common denominator from not ONE, but several engine builders who have suffered from pounded in valve seats, morel lifters with forks spreading, rocker arm issues, are they were using the same person for valvetrain components and setups. This wasn't one engine, one builder. Talking multiple builders, and multiple engines, and some even rebuilt , and exact issue showed up again as a repeat, as there was no desire by the supplier, to find the root cause of the initial issues. The other coincidence, was these issues showed their faces, at very close time intervals in the several engines.

Originally Posted by phragle

Couple of thoughts here...

Mild, you mentioned the specific setup living longer in a 632 vs a 454... Now aside from possible differences in say a tall vs short setup the cam, and assorted valvetrain would be going thru the exact same motion iregardless of the cylinder bore or crank stroke, That setup may be COMPLETELY wrong as far as making actual power in a 454, but how would lifespan be any different when the ;parts are moving exactly the same in either engine (there very well may be a good legitimate reason, but my brains not getting it at the moment)

And 2..it comes down to testing. merc stuff lives because they test the hell out of it. If your building an endurance motor to live in an offshore boat, a 6 second dyno pull eliciting geewhiz chest thumping numbers, while great for a dragster, isnt worth much, when a steady state 6000 rpm loaded pull for a few hours then tear down and inspection would yield much better information. If it makes the power desired AND lives with no problems, then you have something to stand on and its repeatable.

Originally Posted by 33outlawsst

Panther, your not bringing any knowledge of cam's to this thread just stirring the pot, so maybe you should be the next to go

I will go on record to say I have MK spec'd pistons, cams, lifters and cylinder heads in my Smith built 540's and outside the lifters being a little noisy at times I have had Zero issues with them, the power was right on the number and the torque was a little higher than expected,

Originally Posted by SB

MT - I have read from , I believe, Jenkins or Yunik ?, that most of oil temp comes from valve springs. It was like 60 or 70% . I'll have to find some of the writings. Who would have thought it was that much compared to combustion heat. Interesting stuff.

=================

Aeration getting into the cavity of the lifters makes them unstable too. I remember some years back, maybe 10 ? , some people noticing reduced performance at WOT after X amount of minutes...and experimented the idea by putting solid rollers in place temporarily, and being able to continue running as long as they wanted at that rpm. I believe they where running very high 5's or into 6k's ?

Originally Posted by justin29

What power did this package make?