Edelbrock valve spring replacements

[Aussie Charger]

As explained in my PM, the unported heads, dual-plane manifold and 1 5/8" headers will be holding you back. 5600rpm is about right for similar 408 combos. You won't see any more than 6500rpm until you work those heads and get the engine to breath better. But then, you don't really need to see 7000rpm to make 500+hp with a stroker motor - 6000-6300rpm peak power is about what you should aim for if you want a serious street-strip effort 408.

While Edelbrock says the Air Gap is good for 6500rpm, that's on smaller 340/360 engines - you really need a single-plane manifold like an M1.

As a basic rule, if a cam manufacturer describes a grind as, say, 2500-6500rpm for a 340/360, you can subtract about 300-400rpm of that for a stroker to give you an idea of where it should work.

There are better modern cams than the 557 purple shaft, but your present cam is not unsuited to your present combo - you wouldn't want to go much bigger. You need to look at the whole package before deciding on a cam upgrade.

 

[Aussie Charger]

Here's a good article that includes your present cam and compares it to others. Remember, this is a bigger and much better breathing engine than yours, but the basics are there: http://www.moparmusclemagazine.com/...erformance_purple_shaft_camshaft/viewall.html

 

[gumper]

The 4120655 cam in that article is different than mine.. Not sure if they had a misprint or what. Mine is .557 lift, 252 @ 050.

 

[70aarcuda]

the article says 257....could just be a typo....

 

[Aussie Charger]

It's the same cam. See specs here - P4120655 should be identical to yours: http://www.summitracing.com/int/parts/dcc-4120655/overview/

The reason for the discrepancy is the magazine used 1.6 rockers - not 1.5 - so the quoted lift is higher and also duration @.050" is slighter longer with the bigger rockers. You can also alter duration @.050" using more or less lash on solid cams.

 

[Aussie Charger]

If you want to see the effects of a bigger cam, you could change the springs and try a set of 1.6 rockers.

 

[gumper]

I forgot I have a $100 gift card for Edelbrock. Looks like I'll be using it to buy a Super Victor.

 

[SS Lancer]

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

Going to run this cam so I will check options u listed thanks again.

 

[SS Lancer]

Sorry wrong photo here is the correct one .

 

[B3422w5]

I run the 16904 trick flow springs on my eddies. They were specced by Dwayne Porter.
My cam is a Howards solid lifter. 260/264@50, 565/565 lift with 1.5 rockers.
Cam makes excellent power and would be better actually on a 408/416 than it is on my 360
Its on a 106, in at 102 per the instructions.
Also went with the Howards EDM lifters which have an oiling hole on the face. Very worthwhile insurance.
May end up using this cam on my 418 with new trickflows build. Probably buy 1.6 intake rockers if i do.

 

[flyfish]

Holy 4 year old thread Batman!

 

[SS Lancer]

Holy 4 year old thread Batman!

Im late to the Party.

 

[Wyrmrider]

some springs have come and gone since that thread back 4 years ago
update is fine
Aussie did do an awesome job

 

[SS Lancer]

If you want to see the effects of a bigger cam, you could change the springs and try a set of 1.6 rockers.

Cam isnt installed its in the box new
My mistake changed to a tunnel ram set up and engine builder wants more duration @ .050 than I currently have so bigger cam is going in .

 

[Aussie Charger]

After going through a set of Pac 1218X springs which didn't handle my cam (HR 232/240, .584/.604), I ended up with a set of Manley Nextek beehive 221438-16 springs. Been running hard for four years now on my 408, and absolutely no issues.

They're not cheap, but there's a good range of LS style double springs that will fit Eddy heads here, and some are pretty stout - probably stout enough for that Crower cam: Manley Performance - Niche Market - Chevy LS Series

 

[SS Lancer]

After going through a set of Pac 1218X springs which didn't handle my cam (HR 232/240, .584/.604), I ended up with a set of Manley Nextek beehive 221438-16 springs. Been running hard for four years now on my 408, and absolutely no issues.

They're not cheap, but there's a good range of LS style double springs that will fit Eddy heads here, and some are pretty stout - probably stout enough for that Crower cam: Manley Performance - Niche Market - Chevy LS Series

I will try to explain CORRECTLY what machinist told me he said he would recommend opening up valve pockets to 1.560" and then can install a good double spring versus bee hive style !!!
Hopefully I said that correctly.

 

[SS Lancer]

After going through a set of Pac 1218X springs which didn't handle my cam (HR 232/240, .584/.604), I ended up with a set of Manley Nextek beehive 221438-16 springs. Been running hard for four years now on my 408, and absolutely no issues.

They're not cheap, but there's a good range of LS style double springs that will fit Eddy heads here, and some are pretty stout - probably stout enough for that Crower cam: Manley Performance - Niche Market - Chevy LS Series

I enclosed a comment machinist quoted does this sound correct ??

 

[Aussie Charger]

Haha! I will try to correctly explain also: have a look at the Manley link I posted and go down to the DOUBLE SPRINGS (which I mentioned).

221436-16 has 155lb on the seat at 1.810" and a rate of 379lb
221435-16 has 170lb on the seat at 1.810" and a rate of 394lb
221421-16 has 165lb on the seat at 1.800" and a rate of 435lb

All those springs will fit Eddy heads without machining and they all exceed the specs Comp Cams lists for similar mechanical rollers (Comp Cams spring 928-16).

I know yours is a Crower cam, but I couldn't find valve spring recommendations on the site. But the above springs should be in the ball park.

All I'm saying is, there are quite a few good double valve springs out there that will fit if you look around. It didn't take me long to find those. Talk to your machinist and ask him what he thinks about putting an LS double spring in to suit your cam. There's no need to machine unless you want to. Valve spring technology has come a long way in recent years . . .

 

[Aussie Charger]

I didn't mean to confuse you by mentioning my own beehives - I was only trying to point out that I rate Manley springs and have been running them for almost five years now without issue. The springs that Pac recommended to me were not strong enough. I, too, would recommend running a double valve spring with your cam.

 

[SS Lancer]

Haha! I will try to correctly explain also: have a look at the Manley link I posted and go down to the DOUBLE SPRINGS (which I mentioned).

221436-16 has 155lb on the seat at 1.810" and a rate of 379lb
221435-16 has 170lb on the seat at 1.810" and a rate of 394lb
221421-16 has 165lb on the seat at 1.800" and a rate of 435lb

All those springs will fit Eddy heads without machining and they all exceed the specs Comp Cams lists for similar mechanical rollers (Comp Cams spring 928-16).

I know yours is a Crower cam, but I couldn't find valve spring recommendations on the site. But the above springs should be in the ball park.

All I'm saying is, there are quite a few good double valve springs out there that will fit if you look around. It didn't take me long to find those. Talk to your machinist and ask him what he thinks about putting an LS double spring in to suit your cam. There's no need to machine unless you want to. Valve spring technology has come a long way in recent years . . .

Thank you - I certainly would love NOT having to open up valve pockets if I don't have to of course.
I will certainly provide ALL your info because I seek guidance because im not educated in this subject !!
Clint Eastwood said it best

A Mans Got to Know His Limitation's !!

 

[SS Lancer]

I didn't mean to confuse you by mentioning my own beehives - I was only trying to point out that I rate Manley springs and have been running them for almost five years now without issue. The springs that Pac recommended to me were not strong enough. I, too, would recommend running a double valve spring with your cam.

Thanks I printed out all you said so I will get something you mentioned since they install without additional work being performed .

 

[Aussie Charger]

Thank you - I certainly would love NOT having to open up valve pockets if I don't have to of course.
I will certainly provide ALL your info because I seek guidance because im not educated in this subject !!
Clint Eastwood said it best

A Mans Got to Know His Limitation's !!

My favourite Eastwood quote.

I only know these things because I've been through it all. Good luck!

 

[SS Lancer]

My favourite Eastwood quote.

I only know these things because I've been through it all. Good luck!

Thank you - I just looked springs up and u are correct all will more than cover my cam request , mine is a flat tappet not a roller but otherwise u nailed it thanks again .

 

[B3422w5]

Haha! I will try to correctly explain also: have a look at the Manley link I posted and go down to the DOUBLE SPRINGS (which I mentioned).

221436-16 has 155lb on the seat at 1.810" and a rate of 379lb
221435-16 has 170lb on the seat at 1.810" and a rate of 394lb
221421-16 has 165lb on the seat at 1.800" and a rate of 435lb

All those springs will fit Eddy heads without machining and they all exceed the specs Comp Cams lists for similar mechanical rollers (Comp Cams spring 928-16).

I know yours is a Crower cam, but I couldn't find valve spring recommendations on the site. But the above springs should be in the ball park.

All I'm saying is, there are quite a few good double valve springs out there that will fit if you look around. It didn't take me long to find those. Talk to your machinist and ask him what he thinks about putting an LS double spring in to suit your cam. There's no need to machine unless you want to. Valve spring technology has come a long way in recent years . . .

Those springs you mention above are suggested for use on a mechanical roller cam? If so must be ultra mild street type cam with super soft lobes. My flat tappet springs are nearly that stout.
I ran a roller that was 240/590 spring pressures and i thought that was moderate spring pressure as that cam saw a lot of street driving. 155-165 seems mighty light.

If for a flat tappet, they are higher than needed unless its a huge ultra agressive grind.
Mine is 260/264 pretty agressive flat tappet and an expert specced out my springs. They are roughly 140/ 365.

 

[yellow rose]

I enclosed a comment machinist quoted does this sound correct ??

View attachment 1715208197

Yep, you machinist is correct. I swallowed the beehive spring crap. I fought them for awhile. Then I just stopped using them.

Open the pockets up, get the correct springs and go.

BTW, ask your machinist to go to b3racingengines.com and look over his tech pages. He WILL have to correct your geometry and Mike has the best system I've found.

Your valve train will thank you for correcting the geometry. I never look at getting the sweep centered. I'd rather have the sweep as narrow as I can and not worry about getting it centered. IOW, I'd rather have a .050 wide sweep that's outboard of center a bit than an .080 wide sweep that's centered.