Any disadvantage to "over-springing"?
02-22-2005, 08:17 PM
#1
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Any disadvantage to "over-springing"? I got a baby cam (221/221 .558/.558 114) which might
or might not be able to work OK with Z06 springs and
Z06 valves (already in hand). I just got a set of Crane
dual springs (832) with titanium retainers which are
the other side of overkill I think. Today's question is,
is there any downside to using a spring that's "too
good"? Given that it's already paid for etc., what if
any downside is there to using a higher lift capable,
maybe (?) higher seat pressure spring? Would there be
any reason not to use the 832s? I'd think that, being
not taken close to their lift limit should give them a
decent life expectancy?
or might not be able to work OK with Z06 springs and
Z06 valves (already in hand). I just got a set of Crane
dual springs (832) with titanium retainers which are
the other side of overkill I think. Today's question is,
is there any downside to using a spring that's "too
good"? Given that it's already paid for etc., what if
any downside is there to using a higher lift capable,
maybe (?) higher seat pressure spring? Would there be
any reason not to use the 832s? I'd think that, being
not taken close to their lift limit should give them a
decent life expectancy?
02-22-2005, 09:07 PM
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the crane/ vinci duals can be set for whatever spring pressure the cam requires. here's specs for the springs.
VHP DUAL VALVE SPRING KIT
112lbs @ 1.800
352lbs @ 1.150
will handle .650 lift with .045 coil clearance
i've been using them on the wife's car for almost a year now on the stock cam. no issues whatsoever. one thing about 'over-springing' is that it's good to go high at first. due to heat cycling and normal wear and tear, you lose spring pressure. so, say, your cam needs 100# seat pressure. i'd go 110# installed. ater heat cycling and usage, it'll come down.
VHP DUAL VALVE SPRING KIT
112lbs @ 1.800
352lbs @ 1.150
will handle .650 lift with .045 coil clearance
i've been using them on the wife's car for almost a year now on the stock cam. no issues whatsoever. one thing about 'over-springing' is that it's good to go high at first. due to heat cycling and normal wear and tear, you lose spring pressure. so, say, your cam needs 100# seat pressure. i'd go 110# installed. ater heat cycling and usage, it'll come down.
Last edited by mrr23; 02-22-2005 at 09:12 PM.
02-22-2005, 09:20 PM
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The only real disadvantage in using springs more stout than you need is the horsepower robbing parisitic loss due to the cam having to push harder to open the valves. remember the only job a valve spring has to do is keep the lifter in contact with the cam lobe. The spring has to have enough pressure to slam the valve shut before the lobe comes back around again.
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02-23-2005, 12:16 AM
#8
i was worried about this over-springing idea as well. i think i may have a collapsed lifter (noise now, pushrods/rockers look good). when i pull the heads to replace (with comp r's i think), i want to replace the valve springs as well (mucho easy w/ heads off). i want to be able to run my stock cam (probably into this summer), but have a damn fine valvetrain already in place for when i get the money to get a 230+ cam like i want and a good tune.
the ppc gold kit w/ dual springs/Ti retainers/seats/seals is looking MIGHTY fine to me! will this be kosher if i am running stock cam/new lifters? i'm always for doing somthing once with good stuff, i dont like learning from mistakes if i dont have to
sorry for my semi-hijacking!
the ppc gold kit w/ dual springs/Ti retainers/seats/seals is looking MIGHTY fine to me! will this be kosher if i am running stock cam/new lifters? i'm always for doing somthing once with good stuff, i dont like learning from mistakes if i dont have to
sorry for my semi-hijacking!
02-23-2005, 08:05 AM
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Right now, I'm running too much spring. I have a GT2-3 cam that LPE specs to use the stock LS6 springs, but I'm running the duals that came on my AFR heads. The LS6s have 90lb. seat pressure, the AFRs are 130lb. (measured by me). The car is running good, and the valvetrain is somewhat quiet, but I know that the springs are costing me power, that they'll wear out sooner because of the more brittle material, that I'm getting more pushrod deflection than I need to, that the guides and seats are wearing faster than they have to, and that the lifters will die sooner.
Next, I'll probably try a set of Comp 915 springs with titanium retainers. They're around 110 on the seat, perfect for my cam. The 918s are over 130, overkill for a mild cam IMO. I gotta get beehive springs back on this car, it looks like a dinosaur with those old design duals on it!
Next, I'll probably try a set of Comp 915 springs with titanium retainers. They're around 110 on the seat, perfect for my cam. The 918s are over 130, overkill for a mild cam IMO. I gotta get beehive springs back on this car, it looks like a dinosaur with those old design duals on it!
Last edited by Flareside; 04-29-2005 at 10:22 AM.
02-23-2005, 12:58 PM
#10
as long as the spring isnt stiffer than the stiffest spring one would use on the most radical hyd roller cam someone would use...the only downfall is gonna be loss of power (not sure if that makes sense ). probably not enough to notice...but if ur trying to get every last ounce of power...then its critical.
not saying this spring is too stiff for you (to where it would rob power)...just saying that "if" if was too stiff youd be leaving power on the table.
). probably not enough to notice...but if ur trying to get every last ounce of power...then its critical. not saying this spring is too stiff for you (to where it would rob power)...just saying that "if" if was too stiff youd be leaving power on the table.
02-23-2005, 01:30 PM
#11
Originally Posted by Flareside
Right now, I'm running too much spring. I have a GT2-3 cam that LPE specs to use the stock LS6 springs, but I'm running the duals that came on my AFR heads. The LS6s have 90lb. seat pressure, the AFRs are 130lb. (measured by me). The car is running good, and the valvetrain is very quiet, but I know that the springs are costing me power, that they'll wear out sooner because of the more brittle material, that I'm getting more pushrod deflection than I need to, that the guides and seats are wearing faster than they have to, and that the lifters will die sooner. Because of all those factors, I'm going to swap out the springs pretty soon. I installed them as an experiment, I wanted to see how much of a different dual springs make in regard to valvetrain noise. The good news is that the springs don't seem to be a noise factor at all, they sounds stock.
Next, I'll probably try a set of Comp 915 springs with titanium retainers. They're around 110 on the seat, perfect for my cam. The 918s are over 130, overkill for a mild cam IMO. I gotta get beehive springs back on this car, it looks like a dinosaur with those old design duals on it!
Next, I'll probably try a set of Comp 915 springs with titanium retainers. They're around 110 on the seat, perfect for my cam. The 918s are over 130, overkill for a mild cam IMO. I gotta get beehive springs back on this car, it looks like a dinosaur with those old design duals on it!
Max Valve Lift : .600"
O.D. : 1.255"
I.D. : .830
Installed Pressure : 115@1.750"
Open Pressure : 350@1.175"
Coil Bind : 1.100"
180$ w/ tit. retainers from SDPC
02-23-2005, 01:51 PM
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Here's a related question for you guys:
When I was doing my cam swap, a friend of mine came over (he has plenty of experience with SBC/BBC's but not as much with LSX's). He told me running the springs I had (PRC duals) might put a lot of stress on my rockers (stock), and I should really consider upgrading to stud-mounted rocker arms. He says it happens with SBC's every now and then (not frequently, but it does happen). What are your thoughts? I know studs would be stronger, but are my rocker arm bolts being put under too much stress right now? Just curious, because his argument did make sense. If so, I guess that would be another drawback of running too much valvespring.
When I was doing my cam swap, a friend of mine came over (he has plenty of experience with SBC/BBC's but not as much with LSX's). He told me running the springs I had (PRC duals) might put a lot of stress on my rockers (stock), and I should really consider upgrading to stud-mounted rocker arms. He says it happens with SBC's every now and then (not frequently, but it does happen). What are your thoughts? I know studs would be stronger, but are my rocker arm bolts being put under too much stress right now? Just curious, because his argument did make sense. If so, I guess that would be another drawback of running too much valvespring.
02-23-2005, 03:35 PM
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Quick thought. If the spring was just a bit stiffer than normal 15-20lb,
then even when worn it might be within spec of the cam. The HP/wear
cost when it is new might not be very high and it might make it worth
the while.
then even when worn it might be within spec of the cam. The HP/wear
cost when it is new might not be very high and it might make it worth
the while.
02-23-2005, 05:25 PM
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kinda what i said. start off with a little more. that way as it wears, it'll lower itself to what you need anyway. but i wouldn't go above 10# more though.
02-23-2005, 07:13 PM
#19
Originally Posted by Turo
Here's a related question for you guys:
When I was doing my cam swap, a friend of mine came over (he has plenty of experience with SBC/BBC's but not as much with LSX's). He told me running the springs I had (PRC duals) might put a lot of stress on my rockers (stock), and I should really consider upgrading to stud-mounted rocker arms. He says it happens with SBC's every now and then (not frequently, but it does happen). What are your thoughts? I know studs would be stronger, but are my rocker arm bolts being put under too much stress right now? Just curious, because his argument did make sense. If so, I guess that would be another drawback of running too much valvespring.
When I was doing my cam swap, a friend of mine came over (he has plenty of experience with SBC/BBC's but not as much with LSX's). He told me running the springs I had (PRC duals) might put a lot of stress on my rockers (stock), and I should really consider upgrading to stud-mounted rocker arms. He says it happens with SBC's every now and then (not frequently, but it does happen). What are your thoughts? I know studs would be stronger, but are my rocker arm bolts being put under too much stress right now? Just curious, because his argument did make sense. If so, I guess that would be another drawback of running too much valvespring.
02-23-2005, 09:51 PM
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Originally Posted by Texas_WS6
If you are worried about your rocker assembley I would sugest to go with pedistal mount rockers, not stud mount ones.