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Should valve spring retainers be hardened?


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I'm working on a 1926 Packard Eight.

I need to make new valve spring retainers and keys for the slotted valve stems because the original ones were discarded by a previous owner.

Do I need to make these spring retainers and valve stem keys out of hardened steel, or can they be non-hardened steel? SHOULD they be NON-hardened?? MUST they be hardened?

I bought the keys from Egge but am surprised that they are a very soft steel.

Our machinist thinks there is no need for the retainers and keys to be hardened because there is no movement between mating surfaces. Only inertial loading. A friend in the restoration business thinks they should all be hardened.

Any opinions?

--Scott

PS: The original Packard spring retainer (the only one I have) appears not to be hardened.

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PMCCs Service Counselor Vol 30, No 7, page 26 says they instituted a change on the intake valve spring seats due to reports of valve keys pulling through the spring seats. They started using Carbo-nitrate hardened spring seats on the intake valves. I remember reading that this also happened to Smokey Yunick at some race or test of the Packard V8 and he had really bad things to say about the Packard V8 - the word "junk" was used. <img src="http://forums.aaca.org/images/graemlins/frown.gif" alt="" /> Now don't shoot the messenger. I also think the later valve spring seats had rubber bonded to the spring seat to help eliminate any oil consumption via the intake valves.

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Randy,

I remember reading that Smokey Yunick story, I believe in Circle Track magazine. I think he was driving a Packard V8 in qualifying when he had the valve spring problem. I don't remember the "junk" comment, but it wouldn't surpise me. He's nothing if not opinionated! Very entertaining to read, though, and I learned a lot of technical aspects of engine performance from his columns. I believe he had a regular column in Popular Mechanics years back. It was called "Say, Smokey." In his later years he had nothing good to say about the "poppet valve 4-cycle Otto engine" and regularly predicted its demise, saying that all the attempted improvements to the basic design were like "putting makeup on an 80-year-old whore" or something close to that. Maybe that Packard experience was the turning-point for Smokey.

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<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I remember reading that Smokey Yunick story, (snip) It was called "Say, Smokey." In his later years he had nothing good to say about the "poppet valve 4-cycle Otto engine" and regularly predicted its demise, saying that all the attempted improvements to the basic design were like "putting makeup on an 80-year-old whore" or something close to that. </div></div>

All the parts reciprocating at mind-boggling speed in a "poppet valve 4-cycle Otto engine" is pretty amazing that it works at all, particularly compared to a turbine or Wankel engine. OTOH, nothing sounds like an American hi perf V-8, so maybe it's why it's ubiquitous, especially in the USA.

Smokey Yunick also "cheated" a lot in the sense of liberally interpreting the racing sanctioning body rules. Gotta love somebody who thinks far outside the box. And wins! <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" />

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It would be nice if Smokey was still around. He'd probably still be making news. Among many other racing innovations, he introduced the oversized fuel line to hold extra gas. Not technically "illegal" at the time, but as soon as he was caught, the gas line size became dictated in the rules. He was also a pioneer of aerodynamics in NASCAR, back when people would say "aero-what?" The story I find most intriguing was the 15/16ths scale "stock" car he built, (I believe it was one of his Chevelles) that is supposedly a bonafied true story.

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The Packard Key-pins are made from about 1/8" thick flat plate steel, can't use rod as a substitute for them. <img src="http://forums.aaca.org/images/graemlins/crazy.gif" alt="" /> They are flat so they will fit the slot type hole in valve-stems and since most of the shear force is on the edge of the wider plate area, they are more durable than a round rod is. I remember someone talking about doing a hardness test on the retainers from Egge, but can't remember the results for sure, but I think they said that they were almost as hard as the originals they had.

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