Valve Float at 6300
12-21-2006, 02:39 PM
#1
Launching!
Thread Starter
Valve Float at 6300 The car has the mods in my sig & im using the Gold double spring's rated at .650 Lift & my cam only has a .595 list, but for some reason my valves started to float at 6300.. The cam has a power band to 6600 Im not sure how much hp that is costing me but what migh be the problem?
Would one single rocker be the cause? I know the back passenger rocker bolt was real hard to get in, maybe the threads were dirty not sure, but i might have gotten a wrong TQ reading out of it. So im thinking that might have been the problem.
So my rev limiter is set at 6200 at the moment
i really wanted it to run at its full potential... now i have to figure this out.
Any ideas?
Thanks Guys
Would one single rocker be the cause? I know the back passenger rocker bolt was real hard to get in, maybe the threads were dirty not sure, but i might have gotten a wrong TQ reading out of it. So im thinking that might have been the problem.
So my rev limiter is set at 6200 at the moment
i really wanted it to run at its full potential... now i have to figure this out. Any ideas?
Thanks Guys
12-21-2006, 03:39 PM
#3
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Thread Starter
Originally Posted by pewter 01 SS
damn first the cam now this.. sux man.. hope you can figure it out..
Its out to get me huh!
Lol... Its alright, it runs! And it runs runs hard. Its just not at its full potential yet thats all
12-21-2006, 04:53 PM
#4
What cam, the F-11? No way gold duals will float on that cam. Something much not be install right. Are you certain youre getting float? Can we see a scan of the dyno graph? Do you have longer valves in there that might be increasing your spring install height?
12-21-2006, 05:34 PM
#5
Launching!
Thread Starter
Originally Posted by GuitsBoy
What cam, the F-11? No way gold duals will float on that cam. Something much not be install right. Are you certain youre getting float? Can we see a scan of the dyno graph? Do you have longer valves in there that might be increasing your spring install height?
I have 7.4's push rod's, what could be installed wrong, or what else could cause this?
Everything is TQ to spec-Except maybe that last rocker arm...I still have to check that, but for sure its not lose.
12-21-2006, 05:52 PM
#6
If its not loose, but not fully tightened to the correct torque then that is likely not the issue. It could be an issue later though.
I agree, need to see the dyno curve. Total valve float would be a big drop in power on the hp with no recovery. Spring surge would be show up as a dip that it might recover from after about 500 RPM.
Any KR show up or other symptoms?
I agree, need to see the dyno curve. Total valve float would be a big drop in power on the hp with no recovery. Spring surge would be show up as a dip that it might recover from after about 500 RPM.
Any KR show up or other symptoms?
12-21-2006, 07:42 PM
#7
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Originally Posted by TWISTEDTA
Its out to get me huh!
Lol... Its alright, it runs! And it runs runs hard. Its just not at its full potential yet thats all
Lol... Its alright, it runs! And it runs runs hard. Its just not at its full potential yet thats all
well yeah at least it runs.. my runs hard to ended up doing 567/528 so not too bad with the futral cam huh lol.. kinda weird mine dies after 6k thought it would spin higher too.. oh well.. well hope you fix it bro.
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12-22-2006, 12:30 AM
#9
Launching!
Thread Starter
Originally Posted by N4cer
. Like from a bad batch .
"pewter 01 SS" Knows why...
Thanks man, ill get it done-Actually no, these cars are never done!
Now im gonna gut the cat's & get me a better Y pipe- Also slap the borla back on and get me a cut out Lol...
I should just dump it and get a ZO6
-Joe
12-22-2006, 10:11 AM
#10
Check your installed height. If you have 1.800", the golds coil bind at 1.090". Take 1.090" + .060" + lift (.595) = 1.745". I would tighten up the springs to atleast 1.770" but you can go as tight as 1.745". This should clear up the valve float if that is what it is. This will increase your open and seat pressure maybe 20lbs and will give you better valve control. A few people that we do heads for, the tighter I go with the spring they get a few hundred more rpm. If it is something with the rocker arms you may find it when doing this.
12-22-2006, 10:24 AM
#11
But shimming dosn't fix the actual problem. Assuming he is at a 1.800 install height, theres no reason an unshimmed gold dual spring shouldn't control this cam well past 7000 rpm.
I suspect either a much larger install height, or another issue altogether, like running out of fuel, or severe detonation. tough to say without a dyno graph.
I suspect either a much larger install height, or another issue altogether, like running out of fuel, or severe detonation. tough to say without a dyno graph.
Originally Posted by Craig@ETPerformance
Check your installed height. If you have 1.800", the golds coil bind at 1.090". Take 1.090" + .060" + lift (.595) = 1.745". I would tighten up the springs to atleast 1.770" but you can go as tight as 1.745". This should clear up the valve float if that is what it is. This will increase your open and seat pressure maybe 20lbs and will give you better valve control. A few people that we do heads for, the tighter I go with the spring they get a few hundred more rpm. If it is something with the rocker arms you may find it when doing this.
12-22-2006, 10:45 AM
#12
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Originally Posted by N4cer
One of my local buddies had a set of gold dual springs from a sponsor and they were pretty weak. Very weak. Like from a bad batch they were so bad. You might wanna check out the springs.
That's not the first time I heard that.
I saw a test of Beehive springs that they maintained good control up to and over 7000 RPM.. Or some crazy # like that. Valve float is controled by the springs.
The comp 918 springs are supposed to be good. Although I've seen someone posted something where one of their springs acutally broke. Comp Cams says it's their NON-Blue stripe springs. And said they have Aleviated the problem.
12-22-2006, 11:12 AM
#14
The reason I am suggesting shimming the springs is to get them closer to coil bind. This will remove some harmonics in the valve spring and add more spring pressure. If it is valve float, this should take care of the problem. I have seen these springs work in may applications and have no problems. You are right with it could be another problem, generally with a hard fall off it is valve train related. Just giving advice, checking installed height is not at hard thing to do when the valve cover is off. If the spring is installed higher, say just thrown in and not checked it could way higher than what is wanted which would give less pressure all around.
The Comp Cams 918 valve springs, really all the beehive designs, work really well. They have great valve contol. The wire that is used in those is different than what a traditional valve spring. Here is a link that gives some good information on them http://www.racingsprings.com/beehivesprings.htm
The Comp Cams 918 valve springs, really all the beehive designs, work really well. They have great valve contol. The wire that is used in those is different than what a traditional valve spring. Here is a link that gives some good information on them http://www.racingsprings.com/beehivesprings.htm
12-22-2006, 11:16 AM
#16
Originally Posted by Craig@ETPerformance
The reason I am suggesting shimming the springs is to get them closer to coil bind. This will remove some harmonics in the valve spring and add more spring pressure. If it is valve float, this should take care of the problem. I have seen these springs work in may applications and have no problems. You are right with it could be another problem, generally with a hard fall off it is valve train related. Just giving advice, checking installed height is not at hard thing to do when the valve cover is off. If the spring is installed higher, say just thrown in and not checked it could way higher than what is wanted which would give less pressure all around.
The Comp Cams 918 valve springs, really all the beehive designs, work really well. They have great valve contol. The wire that is used in those is different than what a traditional valve spring. Here is a link that gives some good information on them http://www.racingsprings.com/beehivesprings.htm
The Comp Cams 918 valve springs, really all the beehive designs, work really well. They have great valve contol. The wire that is used in those is different than what a traditional valve spring. Here is a link that gives some good information on them http://www.racingsprings.com/beehivesprings.htm
12-22-2006, 11:27 AM
#17
It will stress the spring material more and reduce life somewhat, but the consequences of too low a spring pressure will show up quickly with any number of issues. You are better off with a little too much seat pressure than not quite enough. This is with all things being equal. Lightening the valve train on the valve side is another beneficial thing to do as well as stiffening up the pushrod. With the spring loads many are now running and some of the fast rate cams, not to mention some heads require longer pushrods due to the roll over of the valve angle from 15*, I am surprised a lot more guys aren't now running 3/8" pushrods to help stabilize that side of the valve train. From what I understand, some recent Spintron work conducted by Crane showed the 5/16 pushrods looked like guitar springs and they are now beefing up their line of 3/8 pushrods and now also have 3/8 guide plates for their Gold rocker setup. I think that is going to be the trend going forward, i.e., more people and more vendors will make a move the 3/8 pushrods.