Lincoln Zephyr valve spring question

fortyonerag

fortyonerag

Well-known member
I'm doing a refresh on a 59AB (I'm not an engine guy). It's been sitting for a while and has some stuck valves.

It already has 8BA internals - crank, rods valves and pistons.

I ordered a set of LZ valve springs from a very reputable supplier, but the 'LZ' springs don't seem to be as 'beefy' as those I was hoping to replace.

By beefy I mean the steel making up the coil on the LZ spring is a smaller diameter.

Apols if this is a dumb question, but can someone advise me on how to identify Lincoln Zephyr valve springs?
 
I can't tell you how to identify stock LZ springs. What I can say is that spring rate depends on more than just the wire size. If for example a spring has smaller gauge wire but fewer coils for a given distance it may well have a higher rate than a larger wire with more coils. To be sure, one must compress the springs to the "installed ht" distance and compare pressures.



Terry
 
Somewhere there should be a reference to the proper spring compression value for the valve springs of your specific engine. An engine rebuilding shop such as H&H, or where you bought your springs might be able to give you that info. Someone could have installed different springs in the past.
 
'Someone could have installed different springs in the past.'


Indeed! for example, the Isky 185G valve springs are wound from much heavier wire than original ford
 
When it comes to the Lincoln Zephyr valve springs there's two versions. First is the reproduction type and then there's the Isky 185. Having used both in engine builds I have compared them using my spring tester. I have found there's no difference between the two versions at the recommended assembly height. The best way to determine if your Zephyr springs are better is to test them against the other springs.
A note of caution some old stock replacement valve springs the type that list the applications on the box will not only have Ford listed but Lincoln Zephyr as well. These springs are just Ford replacement springs that of course could be used in the Zephyr as well. Recently on Ebay one could find such old stock springs for sale making one think they are getting old stock Zephyr springs buyer beware.
Ronnieroadster
 
If you have or can use someone's drill press for a few minutes, it is easy to determine what you have.
You will also need a common bathroom scale, a small steel ruler and a set of dividers.

First determine the installed height of one of the old springs by measuring one that still installed. Measure just the spring.
Make sure the valve is closed all the way.

Now set the scale on the drill press table and be sure the scale is zeroed. Have the small steel ruler and the set of dividers handy. Set one of the old springs under the chuck.
Pull the handle down till the spring is at the same height as measured for a closed valve. RECORD THE READING ON THE BATHROOM SCALE.
This is the spring pressure on the seat for the old springs.

Now repeat the procedure for the new springs.

For a stock cam, 60 lb. is adequate, for a mild hot rod cam 70
is adequate.

If possible, stay away from china made anything.
That is a recipe for disaster.
 
Pete said:
If you have or can use someone's drill press for a few minutes, it is easy to determine what you have.
You will also need a common bathroom scale, a small steel ruler and a set of dividers.

First determine the installed height of one of the old springs by measuring one that still installed. Measure just the spring.
Make sure the valve is closed all the way.

Now set the scale on the drill press table and be sure the scale is zeroed. Have the small steel ruler and the set of dividers handy. Set one of the old springs under the chuck.
Pull the handle down till the spring is at the same height as measured for a closed valve. RECORD THE READING ON THE BATHROOM SCALE.
This is the spring pressure on the seat for the old springs.

Now repeat the procedure for the new springs.

For a stock cam, 60 lb. is adequate, for a mild hot rod cam 70
is adequate.

If possible, stay away from china made anything.
That is a recipe for disaster.
Click to expand...




Many thanks. This is excellent advice. I will use the better of the two however this engine will probably compete in the grocery getter class only.
 
You can't tell a dang thing from "looking" at them. As Pete noted, the only way to compare is to measure the springs to see what lbs of pressure they exert at what installed height. His method is not a bad way to go . . . at least you'll be close as far as lbs of pressure at X height.

I have a hydraulic spring tester - which I setup in my mill to measure spring pressure. One thing I can tell you is that unless you measure each set - you have no idea as to what you're dealing with (pressure at a specific height).

As Pete noted, there is no reason for excessive spring pressure on a cast-iron, solid lifter street cam . . . the more pressure you apply, the faster your cam will wear out. For a race engine that is running at high RPMs - a completely different story.

Another thing to note is that we're talking about flatheads here - there are no rocker arms, no pushrods, etc - so the valvetrain is very light and our cams are not that wild (usually), so you don't need a lot of spring pressure on the seat or at fully open to control the valve train and prevent float.

Also, if you float a valve, it isn't hitting that nasty piston and doing nasty things. ;)
 
Just a story. My tractor broke a valve spring don't know how. Looked all over for a V8 spring (same as tractor). All I had was Buick straight 8 springs from when I worked at the bus co. which buses used Buick engines which had two springs a big and small per cylinder. The big was to big so I put the small one in and that was oh 20 yrs ago there was no difference in power or rpms still running perfectly and I did not measure the spring just stuffed it in there because our Ford tractor dealer closed down. just saying sam
 
I usually use the stock springs with a .060" shim in a street engine with the Max #1 or similar cams. This usually gives 50 plus pounds on the seat. Application is the answer.
Gramps
 
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