Coil bind...Crap

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64physhy

64physhy

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Ok, first, I know I should have figured this out earlier, but I trusted the place I was getting all my parts through and they said my combo would be good. I don't think they took into account that my rocker arms are 1.65 ratio instead of 1.6.

So I was just figuring, and the springs I have have a 1.090 coil bind and their installed height is 1.750. The lift of the cam with 1.6 rockers is .584/.592. So with 1.65 rockers, that makes it .602/.611. That puts me at .049" below coil bind on the exhaust side, .060" is recommended. Since these are beehive springs, I'm thinking maybe you can push it closer to coil bind, but can't find any info anywhere saying that. Is .049" too tight?
 
Oops. I just rechecked the invoice and found that they are actually installed at a 1.850 height. The 1.750 is the normal installed height with the retainers that were used. So looks like I have .149" before coil bind.
 
Are you saying the spring rates/lbs are rated at 1.75, meanwhile installed at 1.85? what did they go with a stiffer spring and then take the height out of it to decrease the lbs through the lift range?

.050 between each coil @ max lift is perfect.btw

don't forget to deduct lash
 
Another consideration is you lose a little lift on SB Chrysler's because of the lifter/pushrod/rocker arm angle. I just measured mine on the stroker I'm building and the cam lobe lift is .379 on the exhaust side. With 1.6 rockers the valve lift should be .606 but it only measures .591". That is with perfect geometry. I did some tests and found if the geometry is off just a little it can be much more than the .015" mine lost.

BTW: I did my tests with a super light checking spring and repeated the test 3 times on each test sequence so I'm sure nothing lost was from the lifter collapsing or measurement error.
 
1wild&crazyguy said:
Are you saying the spring rates/lbs are rated at 1.75, meanwhile installed at 1.85? what did they go with a stiffer spring and then take the height out of it to decrease the lbs through the lift range?

.050 between each coil @ max lift is perfect.btw

don't forget to deduct lash
Click to expand...

The rates for the springs are at 1.850. They are Hughes 1122's http://www.hughesengines.com/Index/...U3ByaW5ncw==&level2=Q29uaWNhbA==&partid=23347
They cut the spring seats to get the 1.850 installed height. The retainers are 1286's, designed to increase the installed spring height.
 
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