valve train springs 1

[fatman57]

What scope is there to making custom valve springs that retain the factory Tensile strength but lower the energy needed to push the spring down? Is this a bit of an oxymoron?

 

[BrianGar]

This one is the clincher for me Pat,

''What losses will you get if the valves bounce''.

Not to be over-looked!

 

[evelrod]

"What losses will you get if the valves bounce".

Once upon a time...I sure hope it's not still being done...
I was witness to a cam grinder that had built a "stock replacement camshaft" with all the attendant "timing/lift" figures matching the real stock profile....Except the assembly was designed to "float" the valves over the nose for a brief period thus changing the actual performance of the engine to one that would have needed a "performance" profile to equal.
Cheating? Yes, but I don't think he ever got caught. Fast car, too.

Rod

 

[patprimmer]

I heard that was one of smokeys tricks.

I kind of lost an argument once before on how much energy is recovered from valve springs. Bounce is momentary and the follower is in contact for most of the closing stroke. Also the lifter hits the lobe with some extra speed when it catches up.

Regards
Pat
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[fatman57]

sounds like an ok trick to me.........i'd be interested, its not such a bad idea.

what do you mean by 'needed a "performance" profile to equal?'

 

[evelrod]

Pretty simple....If you go to all the trouble to create a profile that will ck as std during scrutineering, then you certainly would want it to equal or at least approach the profile of a performance cam grind. The idea is to be able to cheat to increase performance over your competition and NOT get caught.

In the old days, at least for me, cheating was only when you got caught. All the rest was simply "innovation". ;o)

In Smokey's book there is a chapter on the famous Hudson Hornet's camshaft. When the engines were torn down for inspection, All the engines, Smokey put the bits into a #10 washtub filled with solvent...ALL the engine parts from both cars ! Then as requested, handed each "clean" part to the inspector for examination. Smokey could "feel" the stock from the "cheater" profile camshafts. Gotta love those old days...I sure do.

Rod

 

[Lou Scannon]

I'm convinced, a major contributor to the Hudson Hornet's success in NASCAR was the relentless "innovation" pursued by the leading teams (Marshall Teague, etc...) and the willingness of the factory to adopt the teams' innovations and represent them as factory options. Eventually, Oldsmobile caught onto this, but too little, too late...
Kinda embarrassing, an undersquare flathead six beating all the OHV V8s from 1952 through 1954, Hemi's included (Chrysler, with help of Karl Kiekhafer, finally got serious in 1955 - well, that lasted exactly two years, until Kiekhafer pulled out, though there were other factors...).