Valve Springs

[SStothebone]

Whats better for a procharged, cammed LS3? Dual spring valve spring or the traditional single spring?

[Kilo-9]

I would say it depends upon the specs of the cam.

[SUX2BU]

I would always do doubles for the safety.

[Wilburbeest]

Originally Posted by SUX2BU

I would always do doubles for the safety.

^Exactly what I was gonna say.^

They may be more expensive, but in the event that a spring breaks, the extra investment for doubles could save you a lot of cash in the long run. If one never breaks on you, you still get the peace of mind. Seems like a win either way.

[danhr]

x3

double springs... i would never put a single spring on my vehicle.

Just this one scenario should be enough to sell you on double valve springs.....:

A single valve spring breaks on a motor, you drop a valve, and you have to replace at minimum the cylinder heads, pistons, re-hone/bore the cylinder sleeve, rebalance the bottom end again, we are talking well into the thousands of dollars of repairs.. AT MINIMUM

A double valve spring breaks on a motor. The other valve spring still holds the valve up. Not only do you not blow your motor up, but it will still run! Granted not like it should and I wouldn't suggest revving it to 7k rpms, but you can actually drive it home very carefully and not damage the motor.

[andredmg]

Originally Posted by danhr

x3

double springs... i would never put a single spring on my vehicle.

Just this one scenario should be enough to sell you on double valve springs.....:

A single valve spring breaks on a motor, you drop a valve, and you have to replace at minimum the cylinder heads, pistons, re-hone/bore the cylinder sleeve, rebalance the bottom end again, we are talking well into the thousands of dollars of repairs.. AT MINIMUM

A double valve spring breaks on a motor. The other valve spring still holds the valve up. Not only do you not blow your motor up, but it will still run! Granted not like it should and I wouldn't suggest revving it to 7k rpms, but you can actually drive it home very carefully and not damage the motor.

Dead on, if that doesnt sell you on doubles I dont know what will!!!

[Anthony @ LG Motorsports]

Originally Posted by Kilo-9

I would say it depends upon the specs of the cam.

Exactly....

Sure double springs offer you a bit more safety but to much spring can also be hard on the engine as well.

If the cam does not need a valve spring of that size and pressure then you can rob HP by using it to open and close the spring, increase oil and water temps, increase cam wear, valve seat wear...a number of different things.

You should almost use the lightest spring you can get away with, within reason.

Putting a 400 psi dual valve spring on a stock car is not going to help anything or make it last 10x longer, if anything it will put more wear on everything else.

At the same point an time...when you do go to a larger cam, then it is advantagous to go to a stronger and dual spring setup. Which is why we use the 921 Comp duals with all of our cam kits.

[Angrybird 12]

I've been driving since 1969 and have never had a valve spring break. I have bent pushrods before but never anything to do with valve springs. I don't know it going to a double spring is worth it on a street car unless you have other mods on the engine or intend to run it very hard up to or over redline.

[SUX2BU]

Originally Posted by Skyman 08

I've been driving since 1969 and have never had a valve spring break. I have bent pushrods before but never anything to do with valve springs. I don't know it going to a double spring is worth it on a street car unless you have other mods on the engine or intend to run it very hard up to or over redline.

I've been driving and working on LSx motors for about 12 years. I've seen about 10 different cars break valve springs. 5 of those had single springs and 3 of those 5 needed new motors after they broke, the other two needed the valve replaced. The 5 double springs, only one needed a new valve.

These were all aftermarket springs and cams.

[calbert1999]

Originally Posted by danhr

x3

double springs... i would never put a single spring on my vehicle.

Just this one scenario should be enough to sell you on double valve springs.....:

A single valve spring breaks on a motor, you drop a valve, and you have to replace at minimum the cylinder heads, pistons, re-hone/bore the cylinder sleeve, rebalance the bottom end again, we are talking well into the thousands of dollars of repairs.. AT MINIMUM

A double valve spring breaks on a motor. The other valve spring still holds the valve up. Not only do you not blow your motor up, but it will still run! Granted not like it should and I wouldn't suggest revving it to 7k rpms, but you can actually drive it home very carefully and not damage the motor.

Originally Posted by SUX2BU

I've been driving and working on LSx motors for about 12 years. I've seen about 10 different cars break valve springs. 5 of those had single springs and 3 of those 5 needed new motors after they broke, the other two needed the valve replaced. The 5 double springs, only one needed a new valve.

These were all aftermarket springs and cams.

Any idea why a valve would bend after replaceing the entire head accessories with top notch gear (springs, rockers, et al)? No broken "dual" springs or anything in the heads, just a bent valve (so far)?

[SUX2BU]

Originally Posted by calbert1999

Any idea why a valve would bend after replaceing the entire head accessories with top notch gear (springs, rockers, et al)? No broken "dual" springs or anything in the heads, just a bent valve (so far)?

Valve float.

This could be cause by weak springs or springs where installed height was not checked and shimmed accordingly.

[calbert1999]

Originally Posted by SUX2BU

Valve float.

This could be cause by weak springs or springs where installed height was not checked and shimmed accordingly.

Thanks, for response. So, if spring defective and weakened over time, the valve could have been pushed further down than it should and came in contact with the piston and got smacked hard enough to bend it and or cause other damage to the walls, piston, head, etc...? Or if I"m lucky not other damage?
Also, could something like this be caused if clutch suddenly busted at medium RPM's around 3k, which caused the engine to overreve and exceed some forces for a few seconds?

[CC Performance]

100% depedant on the cam.. I run close to .700 lift and a beehive..LOL 247/263 cam
spring MFG comes into play as well

At the same time I have a 4.8 liter LS engine that we put a 224/231 cam in and are going to run a dual spring.. probably a PAC 1521 in it due to the lobe choice on the cam.



mechanical over rev does happen.... miss a gear ? yes you can force contact

[calbert1999]

Originally Posted by CC Performance

100% depedant on the cam.. I run close to .700 lift and a beehive..LOL 247/263 cam
spring MFG comes into play as well

At the same time I have a 4.8 liter LS engine that we put a 224/231 cam in and are going to run a dual spring.. probably a PAC 1521 in it due to the lobe choice on the cam.



mechanical over rev does happen.... miss a gear ? yes you can force contact

Thinking this was caused from all the issues with the shifter / clutch not going into gear, grinding, getting stuck, pedal stuck to floor, etc....