valve springs

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phoneman

Junior Member
I am rebuilding the engine from my 1940 pickup. I have read several of the recommended books and many threads on here. I am going to run a Schneider 254F cam with .355 lift. My assembled valve spring height ended up right at 2 inches. I measured spring pressure using Ron’s method on the new springs (sealed power) that were provided by the machine shop. The pressure at assembled height is just below 30lbs. If I add 2 .060 shims I am right at 50 lbs. seat pressure. Should I use these springs and shim or try a different spring? I am a little concerned that new springs need to be shimmed that much to get to 50LBS seat pressure.

Thanks
Phoneman
 
phoneman said:
I am rebuilding the engine from my 1940 pickup. I have read several of the recommended books and many threads on here. I am going to run a Schneider 254F cam with .355 lift. My assembled valve spring height ended up right at 2 inches. I measured spring pressure using Ron’s method on the new springs (sealed power) that were provided by the machine shop. The pressure at assembled height is just below 30lbs. If I add 2 .060 shims I am right at 50 lbs. seat pressure. Should I use these springs and shim or try a different spring? I am a little concerned that new springs need to be shimmed that much to get to 50LBS seat pressure.

Thanks
Phoneman
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Just curious, but what is the part number on the Sealed-Power springs?? The ones I have here on the shelf have exactly 60# @ 2.000" I.H.

They are a "progressive" wound spring and work really well.

Thanks, Gary in N.Y.

P.S. Not all that familiar with the '40 units but if it is the same (basically) guide setup as the 8BA you may have an issue "stacking" numerous shims on there, you MAY not have enough height on the spring registers??
 
I need to check my notes, but I believe the LZ springs I purchased from Red's were at 50# @ 2.125. I will check them at 2" and see what I get for reference.
 
Gofast
The Sealed Power springs I have are VS-392. If yours are the same and test good I may need to run back by the machine shop and use a more accurate tester. I appreciate everyone's thoughts on this.

Phoneman
 
phoneman said:
Gofast
The Sealed Power springs I have are VS-392. If yours are the same and test good I may need to run back by the machine shop and use a more accurate tester. I appreciate everyone's thoughts on this.

Phoneman
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Hi "Phoneman", (ya got a first name maybe?), the spring number you'll most likely need is VS-393, these are the ones we stock here. I don't generally stock the 392's (under that number anyway)!

Thanks, Gary in N.Y.

P.S. Would not care to use shims top & bottom, but that's just me. With the 393's (in the photo on the right side) you'll likely need no shims if your measurements are correct!
 

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You need about 60 lbs at 2.00 installed height. Depending on which valves and retainers you have, you may be too long and need shims to get down to 2.00. I'd try to get to 55 to 60 lbs on the seat with that cam . . . you shouldn't need more than that. The correct 'LZ' type springs should work - I think the last set I bought came from 'Reds Headers'.

Good luck,

B&S
 
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The valves are 8ba replacement valves. I did a little looking on the sealed power web site. The VS-392 is a spring for 52-53 flathead V8 and is 2.200 free height. where the VS-393 mentioned is listed 49-51 and is 2.480 free height. It looks like I was supplied the springs for rotators. Thanks for everyone's help.
Braden
 
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I believe the Ford unassembled height at rest is 2.41" with 11.5 coils wire Dia.approx. 0.140", Ford says to change them out if they are 0.125" shorter. This is the 40 stock valve spring 78-6513
 
phoneman said:
The valves are 8ba replacement valves. I did a little looking on the sealed power web site. The VS-392 is a spring for 52-53 flathead V8 and is 2.200 free height. where the VS-393 mentioned is listed 49-51 and is 2.480 free height. It looks like I was supplied the springs for rotators. Thanks for everyone's help.
Braden
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That explains it, they should swap them for the correct springs.
Good job you checked!
Just a note on the Schneider cam. Pay real good attention to the ignition drive slot in the front, and confirm its placing against the stock cam. They can be off line, Mart had this issue recently, think it buggerd up the ignition bushings.
He did resolve the issue on his without changing the cam (being in England, sending it back for sorting by Schneider is cost and time prohibited) I can't remember how he did it, but it's here on a thread someplace.
Martin.
 
scooder said:
Pay real good attention to the ignition drive slot in the front, and confirm its placing against the stock cam. They can be off line,
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I've not seen a cam with the issue - as the slot is meant to be off-center. What I have seen is folks not install the distributor tang with the correct orientation. Basically they get the distributor in 180 degrees out . . . which puts a heck of a side load on the bushing and the timing is all wrong as well. Not saying this was the case as mentioned . . . just wanted to point it out to those who may not see the offset and realize it.
 
The cam I have has the slot offset but by a smaller than correct amount. I made a one off shaft to match by welding and filing the tangs to engage with the incorrect offset.

Mart.
 
Scooder
Thanks for the heads up on the possible issue with the cam. Mine looks like its fine. This is my first flathead rebuild so I am double checking everything.

Braden
 
Mart said:
The cam I have has the slot offset but by a smaller than correct amount. I made a one off shaft to match by welding and filing the tangs to engage with the incorrect offset.

Mart.
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Was the cam core a Ford original? Or was this an aftermarket cam? Sounds like a aftermarket mistake . . . a real pain in the rear one - with an assembled motor looking you in the face! :eek:
 
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