valve spring failure results...
wouldn't that leave SOME kind of debris with the next oil change? Also, the noise characteristic of the valvetrain would change along with some shitty running of the car once a few break, let alone 8.
Not sure about those people, but I expect a particular valvetrain note and sound to come from my engine bay. A single busted spring would really mess that harmony... every start I listen to it in my garage for unexpected sounds. I hear something out of the ordinary, the engine shuts off unless I know what that noise is...
Not sure about those people, but I expect a particular valvetrain note and sound to come from my engine bay. A single busted spring would really mess that harmony... every start I listen to it in my garage for unexpected sounds. I hear something out of the ordinary, the engine shuts off unless I know what that noise is...
TECH Addict
Joined: Nov 2005
Posts: 2,379
Likes: 2
I have the patriots and the valvetrain got noisy a bit, like a sewing machine. What I'm saying is that once you get used to that sound, if a single spring broke, I'd think once under load the noise would worsen to a point that something wouldn't be right. As it stands, with the sewing machine sound, it's still kinda harmonious. A natural I'm a V8 with something done to it engine tapping that's not really tapping. A broken spring (or 8) would change that harmony and then the alarms should go off that something is wrong. I tend to listen for a lot of sounds, I know the sound of a wheel losing a weight very well, the sound of brakes worn down too much. Rod knock (cry). The various smells of exhaust. The feel and sound of suspension parts breaking or the drivetrain (damn 10 bolts).
I think a lot of us that have done our own work on cars for a long time tend to pick up on if anything is wrong with it long before it's major. Maybe it's car hypochondria or something.
I think a lot of us that have done our own work on cars for a long time tend to pick up on if anything is wrong with it long before it's major. Maybe it's car hypochondria or something.
TECH Junkie
Joined: Dec 2005
Posts: 3,092
Likes: 11
Here is my experience with the Comp Cams 918 beehive valve springs. When I installed them on my SBC they measured #115 at 1.800". Spec is 130#. By the way I figure these were from one of the first batch when Comp switched from PAC. They had no paint on them. I was also using the Comp XFI268 cam.
To cut to the chase my power was slowly dropping off. One of the suggestions was the valve springs were at fault. When they were pulled off they measured 95-100# at the 1.800" mark. Had to go down to 1.750" before the needle started climbing again. The good thing was none had broken. I feel the spring pressure had become inadequate for a quick opening cam like the XFI series.
I have sinced switched to the Manley beehives with #150 pounds on the seat. They checked out right on the money spec wise. Will be going back on the dyno in a few weeks.
To cut to the chase my power was slowly dropping off. One of the suggestions was the valve springs were at fault. When they were pulled off they measured 95-100# at the 1.800" mark. Had to go down to 1.750" before the needle started climbing again. The good thing was none had broken. I feel the spring pressure had become inadequate for a quick opening cam like the XFI series.
I have sinced switched to the Manley beehives with #150 pounds on the seat. They checked out right on the money spec wise. Will be going back on the dyno in a few weeks.
Last edited by 1989GTA; Mar 5, 2008 at 06:21 PM.
I set up my dual springs at 1.77 height that produces 135 LBS on the seat and 400 LBS open..I have never had any problems with dual springs...on agressive ramp cam lobes you need good control and longevity which is what you get using a good set of dual springs. I change them out at 40,000 to 45,000 miles. You can buy the Patriot Gold duals kit for $255 or if you are just replacing the springs and do not need the retainers, seats, or locks for $130. That is pretty cheep insurance and peace of mind compared to the damage that a single spring set up causes when there is a spring failure. There have been too many BAD batches of 918s to ever consider using them in my book.
Last edited by slt200mph; Mar 5, 2008 at 02:39 PM.
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I like running a beehive spring because of the lighter weight at the valve tip. I have had Comp 918s since ~03/04 shortly after the first round of breakages when they first put on the blue stripe to differentiate them from the previous bad batches. Fortunately I've have no issues.
What are the other options for a beehive spring that can handle .625 lift?
What are the other options for a beehive spring that can handle .625 lift?
Launching!
Joined: Jun 2007
Posts: 212
Likes: 0
From: NC
I like running a beehive spring because of the lighter weight at the valve tip. I have had Comp 918s since ~03/04 shortly after the first round of breakages when they first put on the blue stripe to differentiate them from the previous bad batches. Fortunately I've have no issues.
What are the other options for a beehive spring that can handle .625 lift?
What are the other options for a beehive spring that can handle .625 lift?
I like running a beehive spring because of the lighter weight at the valve tip. I have had Comp 918s since ~03/04 shortly after the first round of breakages when they first put on the blue stripe to differentiate them from the previous bad batches. Fortunately I've have no issues.
What are the other options for a beehive spring that can handle .625 lift?
What are the other options for a beehive spring that can handle .625 lift?
