Che70velle

iTrader: (6)

Cole, can you elaborate on this? I don’t see how the lifter side of the rocker (fulcrum) knows or cares what the ratio is, as long as the pushrod is adequate. A higher ratio will open the valve faster and higher, which is just exaggerating or multiplying the ramp, without changing duration effectively, which is harder on springs.

How can a camshaft lobe trash a rocker arm?

I agree with your comments on setting up the spring for the rocker ratio. A Spintron is indeed a valuable tool for aquiring data.

grinder11

iTrader: (1)

You obviously have mechanical knowledge and ability. But you also-Obviously-Have little to no machining experience, or you would know heat can-And DOES-Cause work hardening! It is NOT the only cause, but it IS one of them. Try machining some "Flexor M" alloy steel: It starts out cutting easily. If you even slightly cause it to reach, say 400 degrees, it can harden to over 52 Rockwell C, at which time even Carbide tooling starts throwing orange sparks!! Metal doesnt know, or care, what causes the heat. But whether it's heat generated from poor cooling, or from a machine tool, it's grain structure can, and will change. Valve springs are cooled almost entirely from oil. What happens when they don't get enough? Nothing good, for sure.....

ColeGTO

iTrader: (3)

Sorry to disappoint, but I have a considerable amount of machining knowledge in both automotive and aerospace materials. I'd appreciate it if you didn't insult my intelligence by making comments about me directly. You know nothing about me or who I am. You are correct with one thing in your statement though, I don't have experience machining Flexor-M.

Please take the time to do a little research on alloy steel and heat effected strength and you will see that I am correct. Here's a few examples:

https://ntrs.nasa.gov/archive/nasa/c...9630001179.pdf

https://www.cartech.com/globalassets...-pdfs/4340.pdf


Heat generated from machining is not the same as externally heating a part.

Let's keep the topic to materials that are used in an engine. Flexor-M is a Chrome-Moly-Tungsten alloy that is not likely found in an engine. FYI, Inconel 718 will do the same thing (as will most nickel-based alloys) when machining.

Again, work hardening from bending, machining, etc. DO NOT occur in an internal combustion engine.

I'm done trying to educate people on why aluminum is NOT a bad choice for a rocker arm. Take what I've said as opinion and draw your own conclusions, but be sure to understand the facts first.


Cole

Patron

Funniest thing about all this is If you go to a *shaft mounted rocker system* the problem is basically eliminated so why use a factory style rocker. If that's not liked go to a aftermarket head. Point A to B in a straight line...So why beat a dead horse.

G Atsma

Technically, the stock or aftermarket trunnion rockers ARE shaft-mounted on VERY short shafts. The trunnion acts as a shaft. The advantage of the "shaft mounted rocker system" is the stability of the long continuous shaft. Which has NOTHING to do with the design of the actual rocker. The shaft systems just happen to use very good rockers.

Patron

Well all that's fine and dandy...I started reading about BS heat cycles and crap. Straight forward I said this with all the BS to the side. Do what works and you don't have to complain or worry about guides. You got two choices with Ls7 heads aftermarket or......Name one *REAL shaft system* in which guides are going bad on factory heads.....I'm waiting? No hating G but facts are facts. Guy's can complain or just do it right. I already asked a few top builders and this was the answer.

I luv you G.... just want the facts out.

Patron

Quick question and point have you are anyone heard John B (or anyone else with a real shaft style system) replacing guides or ask him or them yourself if I'm wrong. I never asked him myself, yet know the guys who has done the work on both heads besides the others I've talked too. He used factory Ls7's and factory Lsx heads with a Whole lot more of everything...springs, lift, etc.... than hydraulic roller 650 lift cams & springs or factory cams that kill guides with factory style rockers. Should tell you something if guy's read between the lines if using factory heads.

lowcountry

iTrader: (1)

I'll bet a dollar that anyone trying to learn something from this thread is more confused now than before it started...

Patron

Needforspeed66gt on:Speed Talk
Best thing I found about the subject online and Moldstar 90 guides with the above quote.

Che70velle

iTrader: (6)

A LOT of threads end up that way here. There are people that work in the industry, or have worked in the industry with a lot of knowledge here on Tech.
And then you have the individuals that have changed their oil a few times them selves, and watched HotRod tv on Saturday morning that know WAY more than most, and love to argue and insult people. It’s a public forum, and everybody has an opinion. It’s kind of funny actually.
I actually didn’t log in for a couple years on here because of this reason...

I always recommend that anyone coming here with questions, always make sure that you can accept an answer backed by data, and not on opinion only.