testing valve springs

[grumpyvette]

http://www.summitracing.com/parts/PRO-66775/

http://www.popularhotrodding.com/tech/0 ... index.html

http://www.sjdiscounttools.com/lis16750.html

http://www.fordmuscleforums.com/engine- ... tools.html

READ THESE THREAD LINKS BELOW ALSO, AS THEY CONTAIN A GOOD DEAL MORE RELATED INFORMATION


viewtopic.php?f=52&t=1716&p=4248&hilit=retainers#p4248

viewtopic.php?f=52&t=181&p=1066#p1066

viewtopic.php?f=52&t=1376

viewtopic.php?f=52&t=2768&p=7190#p7190

viewtopic.php?f=52&t=528

viewtopic.php?f=52&t=1489

viewtopic.php?f=52&t=788

viewtopic.php?f=52&t=1005

http://www.summitracing.com/parts/MOR-62390/

http://www.summitracing.com/parts/PRO-66774/

now about 90% of the guys looking at this are probably thinking (MORE REAL EXPENSIVE NEARLY USELESS TOOLS)
yeah! when I was about 19 I thought the same thing, now IM not suggesting you run out and buy the tool, but you should understand its function,
I asked an old mentor machinist, what that tool was for and why you use them and got a cheap & fast education in valve train stability from an old machinist and what he said made sence, he grabbed a handful of REJECT springs out of the dumpster and had me test them, they all looked fine, I wondered why he thru them out!. his engine was going to be designed for simple street use so there was nothing really significant in the valve springs to be used, he set it up and showed me that at 1.750 they were supposed to read at 130 pounds and at 1.250 they were supposed to read 290 pounds (about typical for a plain/jane 350 smogger at the time,, some springs, read only 90lbs, one read only 55 lbs I didn,t notice the baddest one, at first, it was cracked, for a second, I thought ID done something wrong, then he showed me some race springs, that looked similar,in a fancy box on his desk, some of those springs ran over 400 lbs. It was not real hard to imaging the difference in wear and valve control that a wide range of valve spring pressures might cause!
then he told me about a guy who had replaced three lifters that, would not (PUMP UP) and clicked at idle, only after wiping a cam lobe did he find the cracked valve spring that was really making the clicking noise)

testing valve springs is a WHOLE LOT EASIER with the correct tools like those linked in this thread

http://www.summitracing.com/parts/CCA-4929/

http://www.summitracing.com/parts/CCA-5333/?image=large


keep in mind you need to check BOTH THE CLEARANCES AND VALVE TRAIN GEOMETRY ALONG WITH THE SPRING LOAD RATES, and the installed height can be varied with shims, valve seat cups, different retainers and keepers and in some cases longer valves
either do it CORRECTLY by buying and learning how to use the tools you need,or get the local machine shop that has the tools and experience to do it for you, theres no way a guy can get the exact measurements and spring load rates at the exact clearances without tools designed to take those precise measurements of length, load rates and clearances, and yes, being off in your measurements by .020-.030 thousands does matter a great deal in some applications!

 

[grumpyvette]

keep in mind cam spec cards give you the intended valve spring load rate,seat diam. specifications and clearances
those specs give you the seat loads installed height and peak loads at max lift, now lets look at both the springs and the cam spec card,because we must get close to the manufacturers intended operational loads, If we get the valve spring load rates too high and you quickly have wear and valve train durability issues like a damaged lifter or cam lobe, and excess heat in the oil,and have lubrication issues, get the load rate to low and you'll enter valve float or loft lifters off the cam lobes and quickly destroy the valve train in the upper rpm range as the lifters are beat silly by impact loads with the cam lobes as they can,t maintain consistent & smooth contact

heres a typical cam spec card



it listed this info

RECOMMENDED VALVE SPRING INFORMATION:
Part # 68390-3 Single Dual X

Approximate spring pressure:
valve closed: 105/115 LBS.
valve open: 330/340 LBS.

valve springs NORMALLY vary about 5-7 lbs between different springs in the same set of springs so don,t get too crazy if they check out slightly different, and lets assume we will use 1.6:1 ratio rockers


ADVERTISED CAMSHAFT SPECIFICATIONS:
INTAKE: Lift: .555
EXHAUST: Lift: .559
which is listed with the stock 1.5:1 ratio
swapping to a 1.6:1 ratio changes the lift to
INTAKE: Lift: .592
EXHAUST: Lift: .596

so we need a spring that clears a minimum of .600 lift, plus .050 mandatory clearance and has similar load rates at the measure or adjusted, installed height, which we find with the valve mic by MEASURING, but keep in mind valve cups and shims can shorten this installed spring height distance and different retainers , valve keeper, different length valves and machining the spring seat in some cases will allow longer lengths to be used within set limits due to clearance issues and thickness of the spring seat in the head casting, so we need to measure the spring seat diam. if we don,t use the suggested manufactures springs if they match or needs

we go to the PAC SITE or your choice of vendor for spring specs...
in this case were looking for a seat load of about 110-120 lbs and an open load at .600 of about 380lbs with a spring bind height that will allow a .650 max valve spring compression

call the spring manufactures for additional info and advice if you don,t have experience as to options, and choices

http://www.racingsprings.com/

http://www.racingsprings.com/PDF/RS2009CAT.PDF

http://www.compcams.com/technical/Catal ... 94-295.pdf

WIDESPREAD LIFTER FAILURE!! MANUFACTURING DEFECTS AND DENIAL!

www.youtube.com

keep in mind shims under the valve springs can be used to raise the spring or shorten the valves installed height, valve locks and retainers can be purchased with non-O.E.M dimensions to adjust the valves installed height or spring load rates
you use either or both depending on the application
a .050 PLUS valve lock moves the retainer .050 higher on the valve stem with no other changes, a plus .050 retainer would move the retainer .050 higher with stock valve locks or an additional .050 if matched to .050 plus locks
if you used a plus .o50 retainer with a set of minus .o50 valve locks the retainer would remain at the stock height on the valve stem