gollum

iTrader: (1)

(This tread has been edited...no broken spring this time...bad plug wire insted)
So far i have broken two Manley single coils intake valve springs and one (the latest) aftermarket beehive exhaust valve spring. Car instantly starts running badly...especially when one breaks on the intake side. When spring breaks on the exhaust side car produced LOTS of unburned smokey exhaust, but does not run quit as bad. 2002 Camaro has 59,000 miles on it. Seems aftermarket springs start breaking around 20,000 miles.

What is the best spring to use to prevent this. I like the simple single coil beehive design, but the aftermarket versions seem to break more often than the factory ones. I have a set of GM blue stripe LS6/LS2 springs i may try...are these springs known for breaking? Cam specs are 224/228 duration @.050", and .570 lift...the weaker 915 springs did just fine with this cam...shifting @ 6200 rpm. I am thinking the LS6/LS2 valvespring will control valves without floating them.

mkvamso

iTrader: (2)

Yellow ls6 springs are designed for a little more lift than the blues. Theyd probably work great for your cam.
Last time i checked sdpc sold them for super cheap, like 60 bucks a set

DietCoke

iTrader: (18)

? The blues are factory replacements for the yellows, with more pressure.

mkvamso

iTrader: (2)

I thought the blue springs were the 01 z06 style springs, with a less aggressive cam than the 02-04, which got the yellow springs
I could be wrong

Brian Tooley Racing

iTrader: (13)

I've seen the yellow springs break on bone stock Z06 engines, so I wouldn't think that's the answer. Google "broken Z06 valve spring" and click on images.

The Platinum springs I sell have never had a failure, and with steel retainers they're only $219 shipped. http://www.briantooleyracing.com/660...retainers.html

redbird555

iTrader: (14)

They were, in 02-04 they changed to yellow however the new oem replacements for those are now painted blue. Stupid I know but thats the way it is lol. Op I would go with BTR springs, PAC1218 or PSI 1511 which is what gm performance parts uses. All good springs, over the years with all the stuff I've read about comp springs you couldnt pay me to run them

Alvin@PCMofNC

I'd skip trying to use the blue or yellow springs and do a quality spring like BTR's

tsquared38016

iTrader: (8)

You may want to verify the proper valve train geometry. Here are a couple of links to Comps tech info explaining the basics.

http://www.cpgnation.com/forum/comp-...zing-5413.html

http://www.cpgnation.com/forum/comp-...ving-5412.html

JakeFusion

iTrader: (7)

If you want to keep a beehive, I'd do the PAC 1211X. Enough spring pressure for that cam and more open pressure than the 1218.

http://www.briantooleyracing.com/625...e-springs.html

garygnu

you need the proper spring pressure to handle the ramp rate intensity of a cam lobe.stock GM springs are ok for stock GM cams .most after market cams have a more intense lobe profile.

Brian Tooley Racing

iTrader: (13)

This only applies to roller rockers, this does not apply to stock rockers.

Stock rockers rock on the valve tip like a rocking chair rocks on a floor. It's a very wide pattern, but trying to shim the rocker up for a more narrow pattern makes the rocker spend more time dragging itself across the valve tip. The more it drags itself, the more valve tip damage and guide wear can occur. If it's a track only car that will see few miles, you can shim the rockers.

You can see in the video the roller tip arcing back in on itself, where it moves towards the exhaust side at mid lift and then moves back towards the intake side at peak lift. This is called "full arc" geometry and is desirable with roller rockers. Stock rockers must work in what's called "half arc" meaning the first half of the same arc. As the second half of the arc is where it's dragging across the valve tip causing damage.

I hope this makes sense.

KCS

iTrader: (20)

Good explanation. I personally cringe whenever I hear of someone shimming their stock LS rocker arms.

gollum

iTrader: (1)

Do you think i could shim the LS2 springs to handle the slightly higher intensity. I know the weaker 915 springs seem to do just fine until one broke at low rpm cruise.

The stock blue stripe LS2 springs are going in regardless. I believe they will work with my stock ls1 rocker ratio. I know the ls6 motor has a higher rocker ratio which does increase intensity also.

The_Bishop

iTrader: (10)

You cannot run any sort of 'stock' spring with an aftermarket cam. Period. The ramps rates on an aftermarket cam are much, much faster than any OEM grind.

The LS6 rocker ratio is exactly the same as the LS1, 1.7:1.

If you have that much of an issue breaking springs, there is something else causing it in your valve train, or you are over-revving it.

gollum

iTrader: (1)

Stock rev limiter. I drive car everyday. Aftermaket single coils are crap. I am going to shim up the Blue stripes.

Do not believe everything you read on the internet or this forum..



....

vettenuts

iTrader: (4)

Don't think the springs you are installing will control the valve train. If they don't, then you will be bouncing valves and introducing loads into the springs that could result in their premature failure. I would suggest you look at the PSI 1511ML valve springs and shim them to 135# on the seat. This should provide valve control for your cam and they are treated for long life as long as they are installed correctly.

One other thought, if you are using the "claw type" valve spring tool like that sold at Autozone this can also be the source of valve spring failure as the metal surface treatment is scratched during installation.

gollum

iTrader: (1)

Thanks for your help. I am using the home made tool that bolts to rocker stud to compress retainer and spring. You turn downward on nut to compress. No "claw type" was used.

BTW the seat pressure of the weaker Comp Cams 26915 springs measures 105 lbs @ stock height. No signs of valve float using them...just breaking

The stiffer behive springs have a well known history of breaking also. Which is why most builders use the dual spring package. Atleast if one breaks, car will be drivable until replaced, but do not rev high or you will bend a valve... if one is not allready bent.

gollum

iTrader: (1)

BTW what are the specs of the stock LS6/LS2 Blue stripe springs. Seat pressue etc....? These springs are designed to last well over 100,000 miles. Should do verygood if shimmed correctly with my cam in sig.

After doing some reasearch, the Blue stripe spring was an upgraded spring over the LS6 yellow stripe spring (which were known for breakage also). LS2 Blue stripes can handle lift of .570 without shimming.

ejbta2

Do yourself a big favor and buy a set of Brian Tooley Racing dual springs and dont mess with them again, little more money now and not changing springs later and buying more cheap springs. do it right the first time.

gollum

iTrader: (1)

Today i tore into motor to find out that no valve spring was broken (i should have ran compression check to be sure). It turned out to be a bad plug wire. Symptoms sounded just like a broken spring on the exhaust side. The Comp Cams 915 springs are still holding up fine with no signs of valve float. My apology goes to Comp Cams. The 915's are so far so good.

The factory plug wires are verygood wires if you are careful taking them off. Sometimes they want to stick to plug and are a pain to take off. I must have damage one awhile back when changing my plugs. I now use dielectric grease inside boot for easier removal. I replaced the wires with the factory looking Autolite FRM-97009 wires (spiral core) from Summit Racing $33.95