Valve Spring Coil Bind--How do you check it? [Archive] - Chevelle Tech

: Valve Spring Coil Bind--How do you check it?


ben70
Sep 3rd, 04, 12:17 AM
I have tried to figure this out and keep getting different methods. I want to check the coil bind on my springs with a feeler gauge (I don't want to hassle with pulling them off and it's got to be relatively accurate while on the heads). Do I just check between one coil or do I check all of them and add it up? Do I add in lash (this is a solid roller)? Can somebody clarify this for me!!??

Thanks!

blazerbob
Sep 3rd, 04, 1:43 AM
With valve fully opened there should be a minumum of .060 between coils of inner and outer springs. If clearance is less will need to change retainer or the valve to gain more installed height, or change to a spring that will acccommodate more lift.

blazerbob
Sep 3rd, 04, 1:44 AM

Wolfplace
Sep 3rd, 04, 2:56 AM
Ben,
You need to take at least one spring off to check coil bind.
It is the total amount the spring will move from full open to where the spring binds & this cannot be measured with feeler gauges.
You will find that the springs will usually not have any where near an equal amount of space between different coils.
Don't forget that most cams are dual pattern & the lift may be different between intake & exhaust ;)
You could probably do it with a dial indicator & a spring removal tool on the engine but it isn't going to be real easy especially with roller springs :D
Once the spring is off you can check it in a vise if you don't have access to a spring tester.

ben70
Sep 3rd, 04, 4:03 PM
Originally posted by Wolfplace:
Ben,
You need to take at least one spring off to check coil bind.
It is the total amount the spring will move from full open to where the spring binds & this cannot be measured with feeler gauges.
You will find that the springs will usually not have any where near an equal amount of space between different coils.
Don't forget that most cams are dual pattern & the lift may be different between intake & exhaust ;)
You could probably do it with a dial indicator & a spring removal tool on the engine but it isn't going to be real easy especially with roller springs :D
Once the spring is off you can check it in a vise if you don't have access to a spring tester. AAwww Mike. I was afraid you'd say that. I've got 315cc AFRs on my 540. The springs are supposedly their Roller Springs (#8003) good up to .750 lift. My cam only goes to .666 lift. I just want to be safe before I fire that monster up.

Wolfplace
Sep 3rd, 04, 8:19 PM
Ben,
With the 8003 spring you will not have a coil bind issue.
What is the cam, that sounds like a Comp street roller & if it is & you didn't order it on a billet you need to lower the spring pressure a bunch or you will kill it :(

TD509EFI
Sep 3rd, 04, 9:30 PM
Ben,

I checked my AFR 315's (after the machine shop checked them) with the valve train set up. Minimum distance was on the exhaust damper springs, had 0.80 minimum clearance with a .702 lift cam. The inner and outer springs had a lot more, about .125" min.

As usual, Mike is dead on with the springs. My 315's did have one shim under each spring, I think it was 0.015", only lowerewd the spring pressure a little over 5lbs. You WILL have to change the springs, I checked with Comp before deciding to go with a billet roller. Their street roller wont handle the AFR spring pressures.

John

ben70
Sep 3rd, 04, 10:25 PM
Okay, here's the cam:

Comp Cams Xtreme Energy Solid Roller
Part Number 11-773-8
Advertised duration: 292/298
Duration @.050 254/260
Lift: .660/.666

Springs: 929-16 (1.535 spring) or 939-16
Dual spring w/ damper
Seat: 150@1.9
Open: 434@1.23
Rate: 437
Bind: 1.18

Am I better off going with the Comp Springs? Do I need different retainers?
Thanks!

Wolfplace
Sep 3rd, 04, 11:39 PM
The -8 is a cast billet roller & you don't want to run over about 475 open.
This is why I never run anything but a Billet solid roller cam.
I don't recall the installed height of the AFR setup but I think it is too tall for the Comp spring & I would prefer slightly more open pressure than the Comp spring has.
Something like 160/450-475 should work pretty good.
You have to remember that you will only have about .640 net lift after lash, deflection & due to the geometry of the goofy pushrod angles in a rat so set the open pressure at about .650 lift. ;)
Try the 953-16 Comp spring & try to get it to 1.9-1.95 installed & it should work good.
Not sure if it will work with your retainers but the 953 takes a 741 retainer which has a 1.115 step. You can measure yours to see if they will work.
Also,,, you want to run the GM melonized distributor gear with this cam.

ben70
Sep 4th, 04, 12:05 AM
Originally posted by Wolfplace:
The -8 is a cast billet roller & you don't want to run over about 475 open.
This is why I never run anything but a Billet solid roller cam.
I don't recall the installed height of the AFR setup but I think it is too tall for the Comp spring & I would prefer slightly more open pressure than the Comp spring has.
Something like 160/450-475 should work pretty good.
You have to remember that you will only have about .640 net lift after lash, deflection & due to the geometry of the goofy pushrod angles in a rat so set the open pressure at about .650 lift. ;)
Try the 953-16 Comp spring & try to get it to 1.9-1.95 installed & it should work good.
Not sure if it will work with your retainers but the 953 takes a 741 retainer which has a 1.115 step. You can measure yours to see if they will work.
Also,,, you want to run the GM melonized distributor gear with this cam. Mike,

Thanks. I'll check out those springs. Changing springs. More fun for me! graemlins/hurray.gif

Pat Kelley
Sep 4th, 04, 3:44 AM
It is surprisingly easy with the right tool. The Moroso (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=2811&prmenbr=361) spring compresser work great.

ben70
Sep 4th, 04, 11:35 AM
Originally posted by Pat Kelley:
It is surprisingly easy with the right tool. The Moroso (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=2811&prmenbr=361) spring compresser work great. Good to hear. That was the tool I was looking at getting to do the job. Thanks.