[Shotimes] Modded SHOs & useless powerbands

[Neno Albert]

> I can see both sides of this argument.

First, I'd like to say I'm not trying to argue nor do I mean to. I love sharing input on ideas,
designs, and what-ifs with a point of view that is different then my own..
 
> You want high revs, and you want to open the valves as much as you can.  To
> make all of this work you have to have valve springs that are stiff enough
> to move the valves and other valve train hardware closed fast enough.  It is
> easier to accomplish with direct acting systems because the valvetrain mass
> is lower.  On the other hand, traditional pushrod engines mastered this long
> ago, even with long duration, very high lift cams used by the racers AND all
> of that extra valve train mass.  Well I say mastered it but that is probably
> overstating the reliability issue.  With all of that mass moving around real
> fast, parts do want to break occasionally.

This is true. However, with a properly built motor, you can expect that to be a mere "casulty" to
wear more or less then something breaking due to poor design. (unless you catagorize parts wear as
a result of poor designing.. and some do.) Especially roller motors. I've seen pushrood roller
motors reving past 9K with EASE! Sure, some require rebuilding only EVERY SINGLE run, but to
compare a motor of that type to a streetable car is insane. I only bring this up to clarify my
view on that before someone yells at me about it. :) OHC motors tend to rev a lot faster then OHV
motors for the most part, but that's because a lot of OHV motors are nothing more then a stamped
steel valvetrain assembly. Hey, if you're going to get some $$$ heads, they sure won't be powered
by stamped steel rockers! ;) I do love the OHC setup and am not turning this into a OHV vs OHC
argument. Some SOHC motors are rocker powered, but mostly all DOHC motors are bucket & shim
operated. (to my knowledge at least.. correct me if I'm wrong)
 
> But wait, I'm going to get to my point here in a minute:
> Most v8's that I'm familiar with use rocker arms with something like a 1.6
> magnification, so with a .3" lobe you get .48" valve lift.  With a direct
> acting system like the SHO, there is no rocker arm, so no magnification, so
> with a .3" lobe you get .3" valve lift.  With a 4-valve engine like the 3.0
> V6 or 3.4 V8, they probably work without needing a lot of valve lift, but
> what about larger engines such as the 4.6?  I know lots of people racing big
> v8's are running .6" to .7" lift.  I don't know if it is practical to get
> that much valve lift without something in the valve train to add some
> multiplication.

Exactly! I also happen to enjoy building computers and especially overclocking (budget builder..
lol) and thank GOD for multiplers!! (which in my sense, play the same roll as a rocker with a
increased ratio) Also, this means you can get a cam with a lesser aggressive lobe grind, which is
exactly what you're saying and I meant. 4.6's use rockers, btw. I don't know about available
ratios and such, but i'm sure there's enough out there for them by now. I know OEM parts were
stamped and their oversized tappets were a 3 piece design which fails at higher RPMs, but THAT is
a design flaw or a design limitation. Not to say all OHC'd rocker setups are a complete failure, though.