Packard Forum Index » Modification Discussion

As you know from running a 427 ford on the track their is no replacement for good parts. you can get "stock" valves from Egge but you are not really dealing with something that I would feel safe putting boost to. Personal opinion would be to go with a custom stainless valve from Manley it wont be cheap but you will never have to worry about them.
Did I read your earlier post right you have a 288 engine? How were you planning on getting to the 359 ci range with it? or did I miss something?

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I got a set of stainless steel exhaust valves from Egge for my '39 Cadillac V-8 several years ago. I would think that Egge makes stainless steel valves for Packard engines too.

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They do but all stainless valves are not crated equal. A lot of more "modern" engines use stainless on the exhaust from the factory but that does not mean it compares to a high performance stainless valve in any way.
Flat heads in general tend to run on the hotter side of things and the L8 Packard really does not have a lot of water in the block when compared to say a 302 GMC 6 or Stove Bolt Chevy 6 which are contemporary though over had valve engines to the straight 8 Packard.
You throw a supercharger on top of that which is known as a general rule of thumb to increase engine heat you have the potential for problems.
Egge sells Packard L8 valves for around $20.00 a piece you will spend close to 4 times that for some super duty custom Manley valves but you get what you pay for.
In my 327 project that will be running forced induction (though it will be at a higher boost lever than the 4psi from a vintage Paxton unit) I wouldn't even consider an Egge valve.
Not saying an Egge valve is a bad valve I have built many stock or slightly modified vintage engines with them with no failures but in something supercharged that is being build for more spirited driving than what most people put there classics through you cant replace quality.

Thanks for the additional comments. Stainless valves are better than the stock steel ones?

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Absolutely stainless are better than stock steel.
I cut my teeth in the racing world working at a high performance machine shop from the ages of 15-21 or so. We would use a stock style steel valve in restoration or pretty much stock engines, with the basic modifications low rise dual plane intake, RV style cam, reasonable compression (as in 9.0 or below on a modern OHV engine) pretty much the car show standard engine 5500 RPM or below.
Saying that a Packard L8 would be screaming its guts out at 5500 RPM but a flat head is a bit of a different animal than an OHV. 9.0 compression is extremely high on a flat motor and they do run hotter so when we built say a V8 ford for racing we tended to over build them. Its almost like 300hp on a flat head is as brutal on components as say 600 on a modern OHV engine.
I have seen a lot of engines run just fine with a stock style valve, so I'm not saying they are bad; however, the number of failures be it burnt valves, excessively worn valve stems ect were mostly on the stock style.
Stainless valves or the more exotic materials such as titanium are not indestructible by any means but they will take more of a beating.
Look at the header design on some bleeding edge performance engines most are made of stainless because it can take more heat before failure. The same is true in valves.
In most modern engines a set of stainless valves can be had pretty cheap the last set I purchased was around 200 dollars for a small-block Chevy engine, in that arena its cheap insurance especially compared to the cost of reconditioning a stock valve.
Sadly this isn't true for the L8 I contacted Manily for a guesstimate quote and with the race series blanks the estimate was around $30 a valve so almost $500 for a complete set and if i went with a more stout valve the price would go up quite a bit. With that you would have the option of going from the 3/8 stem diameter to say 11/32 lighten up the valve train and pick up a few RPM but it isn't a necessity.
With the engine plan I am working towards I will be getting the pricey stainless valves, but if you are staying stock or reasonably close to it the factory style valve should work just fine.
Back to the topic a bit Egge and the comparable restoration part companies produce a product that is adequate for
A) the driving that is typical of how classics are driven today.
B) An engine running well within the stock design parameters.
4psi of boost on the build refrenced in this post is not much roughly 25-30% increase of HP over stock so a 150 hp L8 Packard would be around the 185ish mark on paper with no other changes to the engine. But their will be increased heat in the intake charge and engine will be more detonation sensitive. If you are great at tuning and keep your A/F ratio in the safe range stock style valves might work fine for occasional driving and impressing people at car shows. Anything more than that I would highly suggest a quality stainless valve.