I'm running the edelbrock performer rpm heads on my 408 with a craptastic purple shaft cam. I want to change cams to a Voodoo roller with .600 lift, but have to change springs since the max lift with the installed ones is .575. Do I have a direct replacement spring I can buy and install without needing to do some machine work?
Edelbrock valve spring replacements
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Can you give us some spring dimensions? Like ID and OD? My crystal ball is broken.
txstang84
Well-Known Member
IF it's the as delivered Edelbrock RPM heads for flat tappet cams, it's these...
http://www.summitracing.com/parts/edl-5767
...if the hydraulic roller cam springs, these...
http://www.summitracing.com/parts/edl-5845/overview/
...but like you said, he didn't specify much...
http://www.summitracing.com/parts/edl-5767
...if the hydraulic roller cam springs, these...
http://www.summitracing.com/parts/edl-5845/overview/
...but like you said, he didn't specify much...
what does Lunati recommend for valve springs....solid roller or hydraulic roller????
probably are springs that fit the eddy heads with no machine work...but gotta tell what cam it is ....my crystal ball is out of focus too
probably are springs that fit the eddy heads with no machine work...but gotta tell what cam it is ....my crystal ball is out of focus too
Aussie Charger
Well-Known Member
I've just been through all this, so here goes . . . Edelbrock heads will accept any LS-style beehive and most LS double springs, as the installed height is the same 1.800". You can also increase the installed height of you standard Edelbrock springs to 1.820" to handle .600" springs (see below).
LS beehives will handle just about any hydraulic roller cam with .600"-.650" lift, and all spring manufacturers have them - so plenty of choice.
Valve guide outer diameter is .545" (most LS beehive spring locators are around .565"-.570" internal diameter), and you will need a matching set of 11/32" retainers and locks.
Spring pockets (as machined) will accept up to 1.480" spring cups and shims, so if you decide to go for a double spring, bear this in mind, as many have diameters of 1.500" or more and won't fit without machining the pockets. You basically want a spring with an installed height of around 1.800" with an outside diameter of up to 1.480" and inner spring internal diameter of more than .545" - which still gives you plenty of choice.
Standard LA/Magnum head Edelbrock springs are part #5767 with an outside diameter of 1.460". They are actually a Ford spring with a seat pressure of 120lb@1.830" and rate of around 360lb. You could try to make them work with a .600" cam by using a set of +.050" locks and some shims. You might even get lucky and find when you remove the springs there are enough shims underneath (they are shimmed from the factory) that can be removed to get to your installed height of 1.820" without the +.050" locks. This increases max lift from .580" to .600".
Whether the standard Edelbrock springs can handle your cam or not depends on the cam specs and how old the springs are (and whether or not they've lost much pressure).
Beehives are your best option, IMO, and Lunati has a couple of LS springs that drop straight in and should match your .600" cam (assuming it's a hydraulic roller). Have a look at the 74818 or 75818 (nitrided) LS beehive springs - they're rebranded Pac 1218 and 1518 (nitrided) springs and are the spring of choice for many LS hydraulic roller engines.
You can also buy a complete kit, which includes springs, spring locators, 11/32" retainers and locks. Lunati spring kit 74818K2 has 7 degree locks and retainers, and 74818K5 has 10 degree locks and retainers. Kit 74818K6 has +.050" locks.
If you prefer a double spring, something like Lunati's 74721 pro series will fit and is for similar applications to the beehives mentioned above.
Let me know if you have any questions - with the right parts, it's a very simple swap.
LS beehives will handle just about any hydraulic roller cam with .600"-.650" lift, and all spring manufacturers have them - so plenty of choice.
Valve guide outer diameter is .545" (most LS beehive spring locators are around .565"-.570" internal diameter), and you will need a matching set of 11/32" retainers and locks.
Spring pockets (as machined) will accept up to 1.480" spring cups and shims, so if you decide to go for a double spring, bear this in mind, as many have diameters of 1.500" or more and won't fit without machining the pockets. You basically want a spring with an installed height of around 1.800" with an outside diameter of up to 1.480" and inner spring internal diameter of more than .545" - which still gives you plenty of choice.
Standard LA/Magnum head Edelbrock springs are part #5767 with an outside diameter of 1.460". They are actually a Ford spring with a seat pressure of 120lb@1.830" and rate of around 360lb. You could try to make them work with a .600" cam by using a set of +.050" locks and some shims. You might even get lucky and find when you remove the springs there are enough shims underneath (they are shimmed from the factory) that can be removed to get to your installed height of 1.820" without the +.050" locks. This increases max lift from .580" to .600".
Whether the standard Edelbrock springs can handle your cam or not depends on the cam specs and how old the springs are (and whether or not they've lost much pressure).
Beehives are your best option, IMO, and Lunati has a couple of LS springs that drop straight in and should match your .600" cam (assuming it's a hydraulic roller). Have a look at the 74818 or 75818 (nitrided) LS beehive springs - they're rebranded Pac 1218 and 1518 (nitrided) springs and are the spring of choice for many LS hydraulic roller engines.
You can also buy a complete kit, which includes springs, spring locators, 11/32" retainers and locks. Lunati spring kit 74818K2 has 7 degree locks and retainers, and 74818K5 has 10 degree locks and retainers. Kit 74818K6 has +.050" locks.
If you prefer a double spring, something like Lunati's 74721 pro series will fit and is for similar applications to the beehives mentioned above.
Let me know if you have any questions - with the right parts, it's a very simple swap.
moper
Well-Known Member
Never chose a spring by lift limit. Choose it by use epectations and spring rates vs required pressures. I would just use the springs Lunati recommends & the Lunati springs should drop into the RPM LA heads. You can use the Edelbrock retainers and locks too.
It is the factory Edelbrock 1.46 springs. I want a solid roller, https://www.lunatipower.com/Product.aspx?id=5940&gid=290.
Then look up the same spring from Trick Flow. They sell the same Pac springs at a bunch less $.
26120 comp 195
16120 TFS 140
26120 comp 195
16120 TFS 140
txstang84
Well-Known Member
Bingo!
http://www.racingsprings.com/
I just replaced valve springs on a eddy head with flat tappet...it being a hughes cam ...their recommend spring was a pac spring and they wanted 10 bucks each...I found the same spring at the PAC web site for 5.80....
My guess is this is what they will probably recommend:
https://www.lunatipower.com/Product.aspx?id=6730&gid=191
They used to recommend a different spring with that cam, but the spring has been discontinued. It was this one here:
http://www.summitracing.com/parts/lun-73899lun
I had to have my heads cut to accept a 1.55" diameter spring, if that helps. I don't have as much lift on my solid roller as the cam you listed, so I was able to get away with comp 939-16 springs set up at 1.85". My guess is you will probably need something in the 200# seat and 530# open at a minimum.
https://www.lunatipower.com/Product.aspx?id=6730&gid=191
They used to recommend a different spring with that cam, but the spring has been discontinued. It was this one here:
http://www.summitracing.com/parts/lun-73899lun
I had to have my heads cut to accept a 1.55" diameter spring, if that helps. I don't have as much lift on my solid roller as the cam you listed, so I was able to get away with comp 939-16 springs set up at 1.85". My guess is you will probably need something in the 200# seat and 530# open at a minimum.
I think you actually brought that up the other day. :cheers:
txstang84
Well-Known Member
Nice-I'll have to remember that site-thanks man!
Aussie Charger
Well-Known Member
None of the Lunati recommended springs for that cam will fit the Edelbrock heads without machining the spring pockets. If you can't find a 1.460" spring to suit, you may want to consider the beehives listed above by crackedback (Comp, Trick Flow, Pac etc). The Beehives will work with less open spring pressure, especially if you install them .050" from coil bind, which helps with coil surge. If you're not comfortable running a single spring with a solid roller, you may need to bite the bullet and take the heads to a machine shop. It shouldn't cost that much.
moper
Well-Known Member
After going into the catalogs - yeah - the springs they are recommending would require new spring cups and the pockets being enlarged. Not sure if you can find a beehive that can equal them. Looking in Comp's (Im most familiar with them) they don't have much that wouldn't also require new spring cups, retinares, and locks.. The ones that are close you'll have to mess with matching retainers and locks for the 11/32 valve stems.
But - the Comp 978 dual spring will fit the Edelbrock spring cup and looks to exceed what Lunati's looking for in terms of spring rate and amx lift.
But - the Comp 978 dual spring will fit the Edelbrock spring cup and looks to exceed what Lunati's looking for in terms of spring rate and amx lift.
Eh....I think you might have a typo there. Those springs are good for a decent sized flat tappet, but not a solid roller. Comp 978-16 springs setup at 1.85" are 127# seat and 369# open...that is not enough spring pressure.
moper
Well-Known Member
You're right. I'm trying to do too much here at work...lol.
I think I'll just stick with "get new spring cups and have the spring seats cut for them" advice...lol.
Thanks Fly
I think I'll just stick with "get new spring cups and have the spring seats cut for them" advice...lol.
Thanks Fly
Aussie Charger
Well-Known Member
Go to the Pac site and have a look at their catalogue here: [ame]http://www.racingsprings.com/Multimedia/www.RacingSprings.com/Files/PACValvetrainCatalog.PDF[/ame]
There are a number of dual springs that will fit without machining. You may want to have a look at the 1237X spring - that's closest to the recommended Lunati spring for your cam and will fit without any work. The 1529 and 1530 springs are also close. However, you will need to check with Pac to ensure they have the correct 11/32" "mini 8" (8 degree) locks to suit the retainers, as they are usually to suit 8mm valves. The 1500 series springs are also nitrided and can be expensive.
It may be cheaper just to have the heads machined for 1.500+" springs - you'll have a much bigger choice.
Failing that, there are a couple of beehives that *may* work with your cam - 1220, 1520 - but you would need to talk to Pac about that. They have less spring pressure but the lighter spring and retainers may compensate - especially if you shim them up to higher seat pressures (which you can do with only .600" lift) and only use 1.5 rockers. I run similar springs in my hydraulic roller with 170/370lb pressures - but my cam isn't nearly as aggressive as the one you have chosen.
If it were me, I'd probably just get the heads machined and go with the suggested spring.
EDIT: I've just found what you might be looking for: http://www.summitracing.com/int/parts/kmo-k-800/overview/
Shim it down to 1.750" and you'll have 212lb on the seat, 495lb @.600", they will use the same 1.460" spring cups and - by the looks of it - the same retainers as you current Edelbrock springs. And they're $100 a set.
BTW, you know you will have to grind/drill the heads anyway to fit 3/8" or larger pushrods - you can only get 5/16" pushrods into Eddy heads without enlarging the pushrod holes (and be VERY careful doing that, as it's easy to break through the pushrod pinch into the intake port). Even a tapered 3/8"-5/16" pushrod won't fit. Manton makes an 11/32" pushrod that will fit with a very small amount of clearancing.
There are a number of dual springs that will fit without machining. You may want to have a look at the 1237X spring - that's closest to the recommended Lunati spring for your cam and will fit without any work. The 1529 and 1530 springs are also close. However, you will need to check with Pac to ensure they have the correct 11/32" "mini 8" (8 degree) locks to suit the retainers, as they are usually to suit 8mm valves. The 1500 series springs are also nitrided and can be expensive.
It may be cheaper just to have the heads machined for 1.500+" springs - you'll have a much bigger choice.
Failing that, there are a couple of beehives that *may* work with your cam - 1220, 1520 - but you would need to talk to Pac about that. They have less spring pressure but the lighter spring and retainers may compensate - especially if you shim them up to higher seat pressures (which you can do with only .600" lift) and only use 1.5 rockers. I run similar springs in my hydraulic roller with 170/370lb pressures - but my cam isn't nearly as aggressive as the one you have chosen.
If it were me, I'd probably just get the heads machined and go with the suggested spring.
EDIT: I've just found what you might be looking for: http://www.summitracing.com/int/parts/kmo-k-800/overview/
Shim it down to 1.750" and you'll have 212lb on the seat, 495lb @.600", they will use the same 1.460" spring cups and - by the looks of it - the same retainers as you current Edelbrock springs. And they're $100 a set.
BTW, you know you will have to grind/drill the heads anyway to fit 3/8" or larger pushrods - you can only get 5/16" pushrods into Eddy heads without enlarging the pushrod holes (and be VERY careful doing that, as it's easy to break through the pushrod pinch into the intake port). Even a tapered 3/8"-5/16" pushrod won't fit. Manton makes an 11/32" pushrod that will fit with a very small amount of clearancing.
Will these work?
http://m.summitracing.com/parts/cro-68380x2-16
May be a little light on the open pressure. If so then I'll probably do those K-Motion springs. Lunati recommended 180 seat pressure and 480 open up to 7000 rpm. I'm getting away with running a solid cam with the Edelbrock hydraulic springs now, I seem to have luck on my side.
http://m.summitracing.com/parts/cro-68380x2-16
May be a little light on the open pressure. If so then I'll probably do those K-Motion springs. Lunati recommended 180 seat pressure and 480 open up to 7000 rpm. I'm getting away with running a solid cam with the Edelbrock hydraulic springs now, I seem to have luck on my side.
Aussie Charger
Well-Known Member
They should work OK. They have slightly more seat pressure @ 1.800" (197lb vs 189lb) and about the same open pressure @ 1.200" (470lb vs 472lb) as the K Motion springs.
Shimming the Crow springs to 1.760" and 1.160" (.050" from coil bind with a .600" lift cam) gives you 215lb on the seat and 490lb open.
Shimming the K Motion springs to 1.750" and 1.150" (also .050" from coil bind) gives you 212lb on the seat and 495lb open.
They end up being pretty similar. Plus those springs will fit without machining. I'd say go for it.
Shimming the Crow springs to 1.760" and 1.160" (.050" from coil bind with a .600" lift cam) gives you 215lb on the seat and 490lb open.
Shimming the K Motion springs to 1.750" and 1.150" (also .050" from coil bind) gives you 212lb on the seat and 495lb open.
They end up being pretty similar. Plus those springs will fit without machining. I'd say go for it.
I'm having second thoughts about getting a roller cam. I never get over 6500 rpm (peak power is about 5600), and thinking maybe a solid cam is better suited for me like voodoo 30200743. Plus the solid roller will cost me near $1000 by the time I get all the supporting parts. I may as well post my build:
408 c.i.
Scat forged assembly
10.9:1 compression
Edelbrock heads, off the shelf
Comp roller rockers
Mopar purple cam P4120655
Smith Bros 5/16 pushrods
Air Gap intake
Bigs stage 5 750
Hooker 1 5/8 headers
408 c.i.
Scat forged assembly
10.9:1 compression
Edelbrock heads, off the shelf
Comp roller rockers
Mopar purple cam P4120655
Smith Bros 5/16 pushrods
Air Gap intake
Bigs stage 5 750
Hooker 1 5/8 headers
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