Valve springs, roller cam
#2901380
03/21/21 04:58 PM
03/21/21 04:58 PM
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Joined: Jan 2005
Posts: 4,417 Michigan
MarkZ
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I've got a big block apart for various reasons and I'm double checking it has the right parts in it. It was assembled by a shop and I picked it up and installed it as it was a few years back. I explicitly remember asking the builder if he had to change out the springs on the heads to accommodate for the roller cam and he said no.
Heads are Edelbrock 84cc RPM Performer and the cam in a Comp XR280HR roller.
These heads come in two flavors: dual spring for roller cams and single for flat tappet. Both the dual and single have dampener springs. Looking at what I have they look like singles with a dampener (unless I'm blind). I can't find pressure ratings from Edelbrock. Comp requires 370 to 395 pounds open spring pressure.
These are singles with a dampener? Right?
1987 Fifth Avenue - 512/518/D60
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Re: Valve springs, roller cam
[Re: MarkZ]
#2901396
03/21/21 05:48 PM
03/21/21 05:48 PM
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Joined: Jan 2003
Posts: 1,760 Windsor, ON, Canada
Diplomat360
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Mark, Yup, that's a single spring with a dampener.
If the border wasn't shut down you'd be welcome to use my on-head checker, but that would only get you an approx spring rate (by collapsing the spring 0.500" and measuring the results). Looks like the only other option would be to pull a couple of these and get them tested on a spring checker?
At least you'll get the spring free height, and that might help narrowing it down to a known spring through a parts catalog.
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Re: Valve springs, roller cam
[Re: Stanton]
#2901519
03/22/21 09:46 AM
03/22/21 09:46 AM
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Joined: Jan 2003
Posts: 10,718 North Dakota
6PakBee
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This is something I'm real foggy on. Every time I ask one of my racer friends about valve springs for roller cams they start talking about the necessity to run springs with unreal seat pressures. But yet, you look at the valve springs that a Magnum uses and they aren't that radical. It has to be more than just roller versus flat tappet, more like what kind of roller profile that determines what kind of spring is necessary. Did I tell you this topic confuses me?
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: Valve springs, roller cam
[Re: 6PakBee]
#2901551
03/22/21 11:17 AM
03/22/21 11:17 AM
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Joined: Jan 2005
Posts: 4,417 Michigan
MarkZ
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This is something I'm real foggy on. Every time I ask one of my racer friends about valve springs for roller cams they start talking about the necessity to run springs with unreal seat pressures. But yet, you look at the valve springs that a Magnum uses and they aren't that radical. It has to be more than just roller versus flat tappet, more like what kind of roller profile that determines what kind of spring is necessary. Did I tell you this topic confuses me? Well, you're in good company. Eddie lists the double spring head as being for roller cams and the single spring head for flat tappet - both don't give spring rates. The Comp Cams specs shows two springs that will work, a single and double - both with open spring pressures between 370 and 390lbs. My builder said the springs didn't need to be changed. I bought the heads assembled. I'm going to call the builder today. The whole thing that started me down this rabbit hole was an issue of a push rod falling out from under the rocker (I have a separate thread for this). I was just being anal in going over the rest of the parts.
1987 Fifth Avenue - 512/518/D60
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Re: Valve springs, roller cam
[Re: MarkZ]
#2901571
03/22/21 12:13 PM
03/22/21 12:13 PM
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Joined: Aug 2003
Posts: 43,185 Bend,OR USA
Cab_Burge
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One thing to keep in mind on solid lifter steel roller cams, not cast cores, is using a lot more pressure than the cam makers suggest is way better than a tiny bit to little been here done that Hydraulic roller lifters are a different issue altogether, maybe 180 lbs. on the seats and 350 lbs. open may work okay as long as you don't want to see north of 6000 RPM + IHTHs EDITED: I have only use one hydraulic roller cam in a 426 street hemi years ago, it was a custom Comp Cams grind and I was told to use spring pressure that I can't remember now The lifters would not adjust properly, no matter how I adjusted them, to be quiet. That motor sounded like the old .030-.030 solid lifter SB Chevy Corvette motors did I heard later that Comp sent back 1500 sets of that brand lifters due to this issue I have a customer who wants to run a hydraulic roller cam on the street and wants to make north of 600 HP with a 408 C.I. pump gas 360 motor, I'm almost sure that is not going to work with any hydraulic lifters, let alone a hydraulic roller lifter
Last edited by Cab_Burge; 03/22/21 12:23 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Valve springs, roller cam
[Re: Stanton]
#2901672
03/22/21 03:35 PM
03/22/21 03:35 PM
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Joined: Jan 2003
Posts: 4,722 Moved to N.E. Tennessee
GomangoCuda
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Moved to N.E. Tennessee
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Eddy is probably no different than Indy. They advertise the heads with "valvesprings good for .600" lift". But that's not .600" lift with a roller cam !! X2 When they say good for .600 lift it just means it won't coilbind at that lift. It does not mean that the pressures are correct for any specific cam and lifter combo.
Last edited by GomangoCuda; 03/22/21 05:48 PM.
In theory, there is no difference between theory and practice. In practice, there is.
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Re: Valve springs, roller cam
[Re: Mcode69]
#2901902
03/23/21 08:55 AM
03/23/21 08:55 AM
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Joined: Jan 2003
Posts: 10,718 North Dakota
6PakBee
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Hydraulic roller, solid street roller, solid race roller are all different animals and will all require different springs, it's the same story as it always was, follow the cam manufacturers recommendations. I don't know if it's all that simple to just say "use the cam manufacturer's recommendations". Say I have a stock 360 Magnum and want to use other than OEM springs (cost item), what do I go looking for?
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: Valve springs, roller cam
[Re: GomangoCuda]
#2908520
04/09/21 09:00 PM
04/09/21 09:00 PM
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Joined: Jan 2005
Posts: 4,417 Michigan
MarkZ
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Made a little more progress and got a few more questions. Took it all apart and my heads already have the spring cups installed. There was also a shim under the spring that would only come off after removing the valve seal.
I was able to get through to Edelbrock and they gave me the part numbers I needed to get the correct springs on the heads.
Springs: 5821 Valve Seals: 9758
The dual springs for roller cams are the same diameter and use the same cup, retainers and locks.
The new springs have an open pressure at 384lbs. That is 42lbs higher than the old springs and is pretty close to the recommended springs from Comp Cams.
To measure the height I installed a check spring from my cam timing kit and used the depth gauge on my dial calipers to measure the distance from the spring cup to the bottom of the retainer. Came up with a distance of 1.910" and the springs call for an install height of 1.900".
First question is this acceptable or is a shim needed? I don't know what the allowed tolerance for height is with valve springs.
Next question is if you look at the pictures the shim I removed has a groove worn into it. Is this normal? I'm questioning installing springs now without it thinking this could happen to the cups on the heads.
Last question concerns installing the new seals. I saw it done on another set of heads using a deep well socket and a dead blow hammer. Is this the way this should be done?
I really appreciate the help everyone. I've always had a shop assemble heads for me. This is really my first time measuring and setting up a valve train. Thanks again.
1987 Fifth Avenue - 512/518/D60
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Re: Valve springs, roller cam
[Re: MarkZ]
#2908697
04/10/21 11:09 AM
04/10/21 11:09 AM
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Joined: Jan 2003
Posts: 1,760 Windsor, ON, Canada
Diplomat360
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Re: wear and placement of the shims, like B1MAXX said, and based on the feedback I got from the forum on my W2 setups the 0.010" wasn't a big problem, provided that it's not short-changing you in terms of the actual load the spring is providing. Re: seal installation tool...I had previously used the long socket but was never comfortable with the hex inside being, well hex, as opposed to circular and therefore not properly driving the seal down around it's circumference. So here is a handy little tool that does an awesome job on this task => Comp Cams Valve Seal Installation ToolEDIT ==== If you buy the tool make sure you get the right sized one, there are different ones given the different sizes of the seal diameters.
Last edited by Diplomat360; 04/10/21 11:11 AM. Reason: tool sizing note
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Re: Valve springs, roller cam
[Re: Cab_Burge]
#2909382
04/12/21 09:15 AM
04/12/21 09:15 AM
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Joined: Aug 2006
Posts: 2,511 God's Country Maryland
GODSCOUNTRY340
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Yes you need shims under those springs with aluminum heads, if you don't use them the springs will eat your heads. The reason for stiffer springs for roller cams is due to the roller lifters being a lot heavier than non roller lifters. You need those stronger springs to keep valve float down and to keep those lifters in contact with the cam. If your springs have the correct spring pressure rating required for your cam, use them. Your machine shop most likely tested your spring pressures and that's why they said they were go to go.
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