1940 RTN valve spring installed height spec

avery2550 · Feb 25, 2017

I'm finishing up assembling the engine on my
1940 RTN with new valves and springs. The
manuals I have don't list a valve spring
installed height. Was hoping somebody could
help me out if they had a more detailed
manual with the spring installed height
specification so I can get them shimmed
right if needed.

Thanks
Matt

T.R.K. · Feb 26, 2017

Charlie Biler at external_link.com is the only person I know of that may have that information. I think he had those springs reproduced.

As far as i know, most people just put the valve springs in and they work fine as long as they are not 'tired' or weak. Its not like its a 6,000 rpm small block. I always did and they always worked.

avery2550 · Feb 26, 2017

A friend was able to find the specification of 1 9/16" at their machine shop today. So I checked them and have them assembled. I shimmed one exhaust .030" was it. Exhaust valves are the ones that will give trouble if not enough closed spring pressure when idling or a no load situation causing a miss.
Thanks for the reply.

molinegb · Feb 28, 2017

Valve springs 1 19/32 when fully expanded. Valve springs compressed to 1 9/16 has 27 1/2 pounds pressure. Compressed to 1 13/64 requires 56 lbs pressure. Should help some.

1940 RTN valve spring installed height spec

avery2550

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T.R.K.

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avery2550

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molinegb

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