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steelcomp was here
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can someone tell me the correct way to check for coil bind
on valve springs?

BBC roller cam, solid roller lifters, 1.7 ratio rockers
The best way is on a spring checker or in a vise. Put a retainer on the spring and compress it until it won't go any further. If you're running dual springs, make sure the inner spring is there. When compressed, measure the stack. That's your coil bind dimension. You can subtract that from your net lift and installed height and get your clearance. If the engine is assembled, you can just run the valve to max lift, and if you can see daylight through the coils, you're good.:)devil
OK...maybe that's oversimplifying things, but seriously, you can check between the coils with a feeler gauge. If you know the specs for the spring, and you can measure the lift, you can do it mathematically, but measuring it is best.
 

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Discussion Starter · #3 ·
the engine is assembled, and no daylight between the coils
whats the next step? should this have been checked mathematically
by the engine builder? does this mean I have the incorrect springs for the cam?
 

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steelcomp was here
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26,529 Posts
the engine is assembled, and no daylight between the coils
whats the next step? should this have been checked mathematically
by the engine builder? does this mean I have the incorrect springs for the cam?
It could be as simple as not enough installed height, but this sort of opens a can of worms.
I'd ask about valve lash, but at this point, even if you don't have any, it's not going to be enough to help.
What kind of info can you give? Spring part no? Lift, rocker ratio, installed height, spring specs, anything else?
 

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steelcomp was here
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By the way, you probably already know, but STOP WHERE YOU ARE! Don't continue rolling the engine over, and surely don't run it, or you can damge things.
 

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Installed height minus full bind height is the max spring travel. That number needs to be at least .060 (some say.050, we like a bit more) greater than the max lift of the valve.
 

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steelcomp was here
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Coil bind is pretty basic. If overlooked, a lot of other problems can get blamed, when all along, coil bind was the culprit. Broken parts, unnecessary dmage, and blaming others for an unnecessary mistake.:p Let's try and avoid that if we can.
 

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the engine is assembled, and no daylight between the coils
whats the next step? should this have been checked mathematically
by the engine builder? does this mean I have the incorrect springs for the cam?

Its very possible that to make what ever spring pressure you needed, the spring had to be shimmed too much which took away some of your travel. Then you would need a stronger spring or longer spring to start with
 

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steelcomp was here
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I was told the more space between the coils, the longer the springs will last. I've got .800 lift and I can use a ruler to measure mine. These were set up by Brodix in 03. No problems yet.

Tim
Springs should be set up to run as close to coil bind as possible, as close as .030" in some cases. Not recommending that but .060-.080 is good. The further from coil bind they are, the more oscillation and instability there is in the spring, which can lead to spring fatigue and/or failure.
 

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ONe would expect that even the most novice engine buider would know to check for coil bind, especially if he was having valve train problems.
What I have seen done Scott is they will not measure the inner step of the retainer and get proper preload on the inner spring. Heads get assembled and the inner springs don't have enough clearance and will coil bind and break. I've seen it several times.
 

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That would be a big concern when running them close to coil bind.

And ... that is pretty common on SBC Vortec heads that someone has put a spring upgrade on. And the outer spring not even anywhere close to coil bind.


What I have seen done Scott is they will not measure the inner step of the retainer and get proper preload on the inner spring. Heads get assembled and the inner springs don't have enough clearance and will coil bind and break. I've seen it several times.
 

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What I have seen done Scott is they will not measure the inner step of the retainer and get proper preload on the inner spring. Heads get assembled and the inner springs don't have enough clearance and will coil bind and break. I've seen it several times.
This scenario can prove tough on other parts of the system also (Roller Lifters, rocker arms ect..) :D
 

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steelcomp was here
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What I have seen done Scott is they will not measure the inner step of the retainer and get proper preload on the inner spring. Heads get assembled and the inner springs don't have enough clearance and will coil bind and break. I've seen it several times.
Someone would have to be completely negligent in checking coil bind without using the retainer and all springs and dampers involved, but I know what you're saying.
 
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