Joined the Dropped Valve Club AGAIN!!! How? UPDATE
01-12-2011, 12:09 AM
#21
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I had good luck with mine with the cam in the sig. Over 25k miles with a lot of time at 6800rpms
918's are rated for .625" lift. Thats what it sez in the paperwork that they come with.
What I mean by improper install, is cranking them down too small during the installation. #8 cylinder is back by the firewall where there isnt a lot of room, right?
918's are rated for .625" lift. Thats what it sez in the paperwork that they come with.
What I mean by improper install, is cranking them down too small during the installation. #8 cylinder is back by the firewall where there isnt a lot of room, right?
01-12-2011, 08:24 AM
#24
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broken springs There is a brake in for the comp cam 918 beehive spring. Run the engine until it reaches proper temp. You can even drive the car 100 miles if you want, just don't go above 4000 rpm and once you shut the car off it stays off over night. Once the springs cool to a "cold" temp they are ready to go. BUT do not hammer on them when cold. The engine should be near operating temp before you really get into it. Don't start the engine and 3 seconds later do a 6800 rpm burnout.
These springs seem to have gotten a bad reputation around this forum and LS1.com. The best parts money can buy will fail if not treated properly or installed right. Comp Cams make good parts, they have to to stay on business. They are at the top of their field. Probably in the top 2 or 3 performance cam manufactureres in the world.
I agree that they had problems with the 1st gen 918 spring but that problem was addressed. Maybe now the failures are more on the driver and not the part????
Even NHRA top fuel engines break.
Just remember..Speed cost money,how fast do you want to go?
These springs seem to have gotten a bad reputation around this forum and LS1.com. The best parts money can buy will fail if not treated properly or installed right. Comp Cams make good parts, they have to to stay on business. They are at the top of their field. Probably in the top 2 or 3 performance cam manufactureres in the world.
I agree that they had problems with the 1st gen 918 spring but that problem was addressed. Maybe now the failures are more on the driver and not the part????
Even NHRA top fuel engines break.
Just remember..Speed cost money,how fast do you want to go?
01-14-2011, 12:24 PM
#27
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The older 918's had the blue stripe while the newer 918's are more like a sliver huge (entire spring). The spring was not redesigned,a upgrade in material (spring steel) resolved the breakage problems.The only yellow striped spring that I am aware of is the LS6 02/04 OEM rated at .570 lift.
01-14-2011, 12:37 PM
#28
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First off.. you had a failure with a 918...and you didnt go doubles the second time?
2nd... 918's may be rated to .600, but it doesnt mean you can push it to that... both your cams are in the .58x range.. thats not enough room for comfort... should have gone with a .625~.650 spring.
3rd... staying with the springs that were installed by a previous owner is a bad choice... you have no idea of how many actual miles are on them, and with a close to rated lift cam, that would have been the 2nd thing I changed after I did an oil change.
the only way to know if a lifter broke would be to tear down the motor and look. and even then, its still just a guess if the lifter caused the failure or if the lifter failure was caused by something else breaking first.
2nd... 918's may be rated to .600, but it doesnt mean you can push it to that... both your cams are in the .58x range.. thats not enough room for comfort... should have gone with a .625~.650 spring.
3rd... staying with the springs that were installed by a previous owner is a bad choice... you have no idea of how many actual miles are on them, and with a close to rated lift cam, that would have been the 2nd thing I changed after I did an oil change.
the only way to know if a lifter broke would be to tear down the motor and look. and even then, its still just a guess if the lifter caused the failure or if the lifter failure was caused by something else breaking first.
01-26-2011, 11:06 PM
#30
from the rocker pic it looks like the left rocker is close to coming apart and could have excessive play in it. I would like to c if the the top of the valve is beat like a mushroom. Have never had any 918s and I have my reasons. Aggressive lobes = duals even on a 220 cam just my opinion.
01-28-2011, 07:32 PM
#31
from the rocker pic it looks like the left rocker is close to coming apart and could have excessive play in it. I would like to c if the the top of the valve is beat like a mushroom. Have never had any 918s and I have my reasons. Aggressive lobes = duals even on a 220 cam just my opinion.
