Valve Spring Selection

SlickVic · 10-01-2007, 10:19 PM

So the motor finally had to come apart. Valve springs are shot after well...3 years. LOL. Need advice on what brand to buy. I want to try two different cams this year. One is 670/625 and one is 640/640 lift. 5300 to 8000 rpm range. 1.550 diameter. Im told i need somewhere between a 200lb to 230 lb at 1.550, 1.900, and 1.950 height range. Any suggestions? K motion? Crane? Manley? Thanks!

Slick Vic
slickvic107@comcast.net

Mike Hedger · 10-01-2007, 11:02 PM

I have had good luck out of the Manley NexTec spring, they used to be reboxed PSI's but I am not sure if they still are. I have mine coated and they run about 300+ passes without any problems at 2.00" installed height 1.640 OD and 305# on the seat.

Tom Goldman · 10-01-2007, 11:13 PM

Hey Vic, 'Bout time you get that thing out! ... Manley Nextek or PSI are the best springs going right now. .... Way longer life expectancy than I have ever gotten from K-motion, and they were pretty good. .... If you can fit it in the overhaul budget, spring for a set that is electro polished, They live even longer, and the pressure drop is VERY low. .......Pick a set that will end up about .060 to .080" from coil bind at max lift, this helps control spring harmonics and improves spring life. .......Run some seat pressure also. 280# -300#... ,the valve job and the lifters will last longer if you control valve bounce. .... Tom

SlickVic · 10-02-2007, 06:09 AM

Thanks for the info Tom. Ive had it out bracket racing this year. Thats why it had to come apart. The alternator decided it was lonely so when the harmonic balancer bolt backed out, the alternator pulled the balancer over so it would have a buddy close by. 9.58 w/o the balancer. Actually picked up .03. So for all you stockers, balancer is worth .03. LOL. Ive teamed up w/ Alan and Glenda Billings though and have been driving their 72 nova, and last week i actually got to drive Red Fred, the 68 Firebird. Fun cars to drive. We may be out next year at some s/st or s/g with their corvette that is near completion too. Im rebuilding this 383 really for a spare. Between the two of us we should have enough stuff to put together a nice 355 that im going to drop in the cavalier. I want to slow it way down so that my fiance can learn to drive. But thats enough rambling. I'll take a look at those springs and see what my money is like.

don R · 10-05-2007, 06:13 PM

If I could run a spring for three years I would get more of the same one.

ldyracr · 10-05-2007, 08:19 PM

I was going to say the same thing about using the same spring again if I got three years out of them...lol.
I have used K-Motion and they just don't last long. I'm using Isky now and so far they have been good.

SlickVic · 10-07-2007, 09:33 AM

Well everything on the motor was good to atleast 8000 rpms. I only turned it at max in really good air, 7600. Most of the time is wasn't over 7400. But, what i don't understand is the springs that came w/ the dart heads, the ones that lasted 3 years, only have a max lift of 650. Im running a 670/625 cam.

Mike Hedger · 10-07-2007, 10:46 PM

Take out the lash from the total lift. .670 - .024 or so for lash. gets you under the .650 limit

Then if you figure in push rod and rocker arm deflection you loose a little more.

SlickVic · 10-08-2007, 04:36 PM

Lash on intake is only .012 which makes it .658...Whats deflection worth??

Mike Hedger · 10-08-2007, 04:51 PM

I checked mine doing cam lift X 1.7 and it comes out to the .808 the cam is advertised as. Then I put it all together like you are going to run it but with 0 lash and checked it again and I come up with .799 at the valve. I tried three different rockers and they were all the same + or - .001 (Crane wide body rockers). But I have around 305 - 310# on the seat and around 800# open spring pressure so it is going to make things move around. I also run the spring within .050 of coil bind and they seem to last longer. I would guess that is why yours lasted so long they were close to coil bind so they did not surge when they were closing the valve.

10-01-2007, 10:19 PM	#1
SlickVic Junior Member Join Date: Jan 2006 Location: Maryland Posts: 81 Likes: 0 Liked 0 Times in 0 Posts	Valve Spring Selection So the motor finally had to come apart. Valve springs are shot after well...3 years. LOL. Need advice on what brand to buy. I want to try two different cams this year. One is 670/625 and one is 640/640 lift. 5300 to 8000 rpm range. 1.550 diameter. Im told i need somewhere between a 200lb to 230 lb at 1.550, 1.900, and 1.950 height range. Any suggestions? K motion? Crane? Manley? Thanks! Slick Vic slickvic107@comcast.net __________________ 87 Cavalier, 92 Corvette, 72 Nova, 68 Firebird

10-01-2007, 11:02 PM	#2
Mike Hedger Junior Member Join Date: Jul 2007 Location: Kemah TX Posts: 93 Likes: 0 Liked 1 Time in 1 Post	Re: Valve Spring Selection I have had good luck out of the Manley NexTec spring, they used to be reboxed PSI's but I am not sure if they still are. I have mine coated and they run about 300+ passes without any problems at 2.00" installed height 1.640 OD and 305# on the seat. __________________ Mike Hedger S/C 4646 MPH Racing and Fabrication

10-01-2007, 11:13 PM	#3
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,436 Likes: 776 Liked 700 Times in 204 Posts	Re: Valve Spring Selection Hey Vic, 'Bout time you get that thing out! ... Manley Nextek or PSI are the best springs going right now. .... Way longer life expectancy than I have ever gotten from K-motion, and they were pretty good. .... If you can fit it in the overhaul budget, spring for a set that is electro polished, They live even longer, and the pressure drop is VERY low. .......Pick a set that will end up about .060 to .080" from coil bind at max lift, this helps control spring harmonics and improves spring life. .......Run some seat pressure also. 280# -300#... ,the valve job and the lifters will last longer if you control valve bounce. .... Tom __________________ Tom Goldman 1500 SG , 1506 STK

10-02-2007, 06:09 AM	#4
SlickVic Junior Member Join Date: Jan 2006 Location: Maryland Posts: 81 Likes: 0 Liked 0 Times in 0 Posts	Re: Valve Spring Selection Thanks for the info Tom. Ive had it out bracket racing this year. Thats why it had to come apart. The alternator decided it was lonely so when the harmonic balancer bolt backed out, the alternator pulled the balancer over so it would have a buddy close by. 9.58 w/o the balancer. Actually picked up .03. So for all you stockers, balancer is worth .03. LOL. Ive teamed up w/ Alan and Glenda Billings though and have been driving their 72 nova, and last week i actually got to drive Red Fred, the 68 Firebird. Fun cars to drive. We may be out next year at some s/st or s/g with their corvette that is near completion too. Im rebuilding this 383 really for a spare. Between the two of us we should have enough stuff to put together a nice 355 that im going to drop in the cavalier. I want to slow it way down so that my fiance can learn to drive. But thats enough rambling. I'll take a look at those springs and see what my money is like. __________________ 87 Cavalier, 92 Corvette, 72 Nova, 68 Firebird

10-05-2007, 06:13 PM	#5
don R Member Join Date: Dec 2005 Location: Illinois Posts: 109 Likes: 0 Liked 0 Times in 0 Posts	Re: Valve Spring Selection If I could run a spring for three years I would get more of the same one.

10-05-2007, 08:19 PM	#6
ldyracr Junior Member Join Date: Mar 2007 Location: Florida Posts: 11 Likes: 0 Liked 0 Times in 0 Posts	Re: Valve Spring Selection I was going to say the same thing about using the same spring again if I got three years out of them...lol. I have used K-Motion and they just don't last long. I'm using Isky now and so far they have been good.

10-07-2007, 09:33 AM	#7
SlickVic Junior Member Join Date: Jan 2006 Location: Maryland Posts: 81 Likes: 0 Liked 0 Times in 0 Posts	Re: Valve Spring Selection Well everything on the motor was good to atleast 8000 rpms. I only turned it at max in really good air, 7600. Most of the time is wasn't over 7400. But, what i don't understand is the springs that came w/ the dart heads, the ones that lasted 3 years, only have a max lift of 650. Im running a 670/625 cam. __________________ 87 Cavalier, 92 Corvette, 72 Nova, 68 Firebird

10-07-2007, 10:46 PM	#8
Mike Hedger Junior Member Join Date: Jul 2007 Location: Kemah TX Posts: 93 Likes: 0 Liked 1 Time in 1 Post	Re: Valve Spring Selection Take out the lash from the total lift. .670 - .024 or so for lash. gets you under the .650 limit Then if you figure in push rod and rocker arm deflection you loose a little more. __________________ Mike Hedger S/C 4646 MPH Racing and Fabrication

10-08-2007, 04:36 PM	#9
SlickVic Junior Member Join Date: Jan 2006 Location: Maryland Posts: 81 Likes: 0 Liked 0 Times in 0 Posts	Re: Valve Spring Selection Lash on intake is only .012 which makes it .658...Whats deflection worth?? __________________ 87 Cavalier, 92 Corvette, 72 Nova, 68 Firebird

10-08-2007, 04:51 PM	#10
Mike Hedger Junior Member Join Date: Jul 2007 Location: Kemah TX Posts: 93 Likes: 0 Liked 1 Time in 1 Post	Re: Valve Spring Selection I checked mine doing cam lift X 1.7 and it comes out to the .808 the cam is advertised as. Then I put it all together like you are going to run it but with 0 lash and checked it again and I come up with .799 at the valve. I tried three different rockers and they were all the same + or - .001 (Crane wide body rockers). But I have around 305 - 310# on the seat and around 800# open spring pressure so it is going to make things move around. I also run the spring within .050 of coil bind and they seem to last longer. I would guess that is why yours lasted so long they were close to coil bind so they did not surge when they were closing the valve. __________________ Mike Hedger S/C 4646 MPH Racing and Fabrication