Comp Cams 918 spring broke......
Originally Posted by DeepBlueZ
well it sounds like yours are fine, but post it up anyway....Maybe we can try to get a read on where things went wrong (assuming the batch numbers are actually sequential.)
Originally Posted by PREDATOR-Z
PSI-LS1511 Valve Springs -
Spring Details:
PSI-LS1511 "Maxlife" beehive Valve Springs, also sold as "Isky Tool Room Springs"
120lbs @ 1.800"
350lbs @ 1.200"
Max lift .625"
Spring Details:
PSI-LS1511 "Maxlife" beehive Valve Springs, also sold as "Isky Tool Room Springs"
120lbs @ 1.800"
350lbs @ 1.200"
Max lift .625"
Here's a photo of them, they are also nitrided for longer life.
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From: Long Island, NY
Originally Posted by speed_demon24
My springs, batch # 051791 have no failures that I can see, they have 3-4K on them. I ordered patriot extremes yesterday though, so I'll know for sure when I pull off my 918's. I didn't feel like risking my motor over the 918's so I ordered the patriots.
interestingly, I just updated my list with THAT exact batch number....somebody lost a whole motor with a spring from that batch!
On The Tree
Joined: Aug 2005
Posts: 142
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From: Speedway, Indiana
I have batch #049045......6,000 miles on them. Thoroughly inspected today and all is ok. Im in no rush to remove them till more info is gathered. But I did want to add my batch # to the mix if it will help the cause.
Last edited by FIVE-O; Jun 9, 2007 at 01:56 PM.
Originally Posted by DeepBlueZ
interestingly, I just updated my list with THAT exact batch number....somebody lost a whole motor with a spring from that batch!
I'm on my second set of 918's with nearly 15k miles on them running a TR224 cam and don't have any problems yet, but I'd also like to add my batch number to the list. Where can I find this on my box? This is what it has labeled on my box "BATCH NUMBER:CT". There's no real "number". 
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Joined: Oct 2003
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From: Long Island, NY
Originally Posted by speed_demon24
Well thats not good, it makes me feel better about ordering the patriots. I guess I won't drive it anymore till I get the new springs on. Do you have a link to a thread he posted in? Just trying to find out as much as I can about how they are failing and after how many miles.
http://ls1gto.com/forums/showthread.php?t=159887
Originally Posted by DeepBlueZ
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i had 918s that broke, i was lucky i was doing a head swap at the time.. when i took the springs off the head they broke instantly.. at least 4 of em did, so i made the move to patriot golds! a much nicer spring
Originally Posted by PREDATOR-Z
PSI-LS1511 Valve Springs -
Spring Details:
PSI-LS1511 "Maxlife" beehive Valve Springs, also sold as "Isky Tool Room Springs"
120lbs @ 1.800"
350lbs @ 1.200"
Max lift .625"
Spring Details:
PSI-LS1511 "Maxlife" beehive Valve Springs, also sold as "Isky Tool Room Springs"
120lbs @ 1.800"
350lbs @ 1.200"
Max lift .625"
FWIW, these springs came on my Dart 225 heads, the cam I was running XFI 236/242 .615/.612 113LSA, I ran this combination for 7,000 miles, before tearing down made a last clean dyno pull, the valvetrain showed no compromise.
Originally Posted by Fraser@SpeedInc
Pretty close, 360lbs. open pressure and they are "1500 series "springs, meaning they have gone though a nitriding process. They arn't maxlife springs, the part number would be followed by an "ML" ML springs go though a different hardening process.
FWIW, these springs came on my Dart 225 heads, the cam I was running XFI 236/242 .615/.612 113LSA, I ran this combination for 7,000 miles, before tearing down made a last clean dyno pull, the valvetrain showed no compromise.
FWIW, these springs came on my Dart 225 heads, the cam I was running XFI 236/242 .615/.612 113LSA, I ran this combination for 7,000 miles, before tearing down made a last clean dyno pull, the valvetrain showed no compromise.
I had to shim them down to 1.75" to control the valves. 
Originally Posted by mvvette97
when i found all my broken springs I called comp and sent them back to them. It took a while but they did send me a new set. I sold them as soon as i recieved them
The difinition of insanity is doing the same thing over and over, but expecting different results.
i'm new to this so help me out here. i just bought a new set of 918s and now don't want to put them on my motor. so my question is, will the patriot duals go on a stock ls1 head without modification to the head?
Originally Posted by LiT1_up
i'm new to this so help me out here. i just bought a new set of 918s and now don't want to put them on my motor. so my question is, will the patriot duals go on a stock ls1 head without modification to the head?
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From: Long Island, NY
Originally Posted by LiT1_up
i'm new to this so help me out here. i just bought a new set of 918s and now don't want to put them on my motor. so my question is, will the patriot duals go on a stock ls1 head without modification to the head?
Originally Posted by speed_demon24
Those springs with only 120 lbs on the seat controlled your valves? When i had 918's installed at 1.8" I was getting valve float at 5800. I had to shim them down to 1.75" to control the valves.
I had to shim them down to 1.75" to control the valves.The 120# @1.800" is simply a rating. Dart installed them at 1.750 so they are about 140# on the seat. The number at 1.800" doesn't mean much, it only gives you a base point from which to determine the required installed height for proper seat loading. There is probably no one on this forum running springs at 1.800", not even the stock springs are set up at that height, they come it at about 1.760". The difference between the PSI and the Comps is the much higher spring rate at 384 lb/in.