edelbrock magnum head valve springs

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MOPARCODY

MOPARCODY

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im running a set of untouched magnum style rpm edelbrock heads with the 380hp crate motor cam in my dart and it doesnt seem to make much power above 5500 rpm.

my qustion is.. are the edelbrock valve springs any good?
they say they are good to 560lift my cam is around 540 ish with my 1.7 rockers
 
you running a solid or hydraulic cam?

ok...crate engine cam....hydraulic flat tappet or hydraulic roller?
 
70aarcuda said:
you running a solid or hydraulic cam?

ok...crate engine cam....hydraulic flat tappet or hydraulic roller?
Click to expand...

its a hydraulic roller. but a magnum style with the oil through push rods

if i remember right its a 288/292 501/513 on a 108lsa but thats based off of a 1.6 rocker and im running a 1.7.

im debating on have a custom cam cut and upgrading the springs and retainers
 
one thing you can do for free...is check to see if they valve springs are at their correct installation height...eddy springs are 120@ 1.800 inches...

but if you are going to change cam....i would upgrade the springs...as the hydraulic rollers are heavy...

also check the preload on the lifters..
 
im just curious if the springs edelbrock uses are any good? i just dont understand why the car doesnt make power past 5500rpm
 
Which heads 61775 or 61779? 61775 has 150 pounds on seat and 420 open at .600 lift which is more than enough. I don't know spring specs on 61779 which has springs for flat tappet cams.
 
61779 1.800" = 120 lbs 1.219" = 320 lbs

61775 1.800" = 150 lbs 1.200" = 420 lbs
 
other question....is the engine running out of fuel .....

got other things that will keep it from gong over 5800
 
70aarcuda said:
other question....is the engine running out of fuel .....

got other things that will keep it from gong over 5800
Click to expand...

it has a holley blue pump with 1/2 line and a holley double pumper. i think im running #72 in the front and #86 in the rear...

are the spring pressure numbers youre talking about? i dont know a whole lot about springs
 
I think Edelbrock uses durable springs. Don't know who actually makes them I've never looked into it but they are very accurate on the spring rates.
 
PoisonDart74 said:
The real question is, does the cam make power over 5500.. :banghead:
Click to expand...

Good question, I would imagine it should with the right parts? The older magazine 340 build people have quoted a few times here lately mentioned that replacing springs allowed the engine to pull cleanly to 6300 as opposed to 5600 (IIRC) with stock spec 340 springs. Power was the same, but it didn't nose over.

OP: does it just keel over above 5500 or just not pull as hard? Aarcuda called a good one...may be other things amiss...
 
MOPARCODY said:
it has a holley blue pump with 1/2 line and a holley double pumper. i think im running #72 in the front and #86 in the rear...

are the spring pressure numbers youre talking about? i dont know a whole lot about springs
Click to expand...


14 jets number from front to back....that is alot....

anyway..

http://www.racingsprings.com/PAC-1903/item/1670

set these to 1.800 install height....get ya 150 lbs on the seat....can use the retainers on the heads already...
 
70aarcuda said:
14 jets number from front to back....that is alot....

anyway..

http://www.racingsprings.com/PAC-1903/item/1670

set these to 1.800 install height....get ya 150 lbs on the seat....can use the retainers on the heads already...
Click to expand...

That jet spread will mess you up BAD unless you have a huge PVCR in the primary metering block! The rear 2 plugs are likely going to look much different than the front 2.

If you have the stock primary metering block go up 3 in the primary and down 3 in the secondaries. Something in the range of 75-83 or 76-82.
 
Good stuff above as far as carb tuning & springs. But if I recall from others that used that engine, that cam was pretty much done around 5500? I know the extra lift with your 1.7 rockers would theoretically give a little more top end, but I believe the low lift numbers "under the curve" is where the power came from with that crate. I think you may need to be satisfied with the performance as is, or maybe look into a different grind with a similar lift and a little more duration while keeping a fairly wide LSA for a broad power curve.
 
Trying to remember what the duration at .050 is on that cam....
 
In my experience, the springs are good for middling cams and lower rocker ratios: I have a similar hydraulic roller in my 408 (292/300 adv, 230/[email protected]", .528"/.548") and the stock Eddy springs allowed the engine to rev to almost 7000rpm with 1.5 rockers.

However, as soon I replaced the 1.5 Crane rockers with 1.65 T&Ds, the cam needed better springs - the heavier rockers and extra .050" lift overpowered them.

I'm now running about 170lb on the seat and 375 open pressure @.584" on the intakes and the engine revs well past 6500rpm.

Interestingly, the engine made more power after the rocker swap, but did it 500rpm lower (440rwhp @ 5500rpm vs 413rwhp @ 6000rpm). It picked up a bunch of torque, but lost a few hundred usable rpm up top.

So your choice is either new springs of go back to 1.6 rockers. You can fit LS-style beehives to Eddy heads - I have a set on mine - as they have a 1.800" installed height, .545" valve guide (.560-.570" LS spring locators will fit) and spring pockets sized for 1.480" cups/shims.

All you have to watch is LS valves are 8mm, so you will need to find 11/32" beehive retainers and locks to suit - but there are plenty to choose from.

The standard Edelbrock spring is part #5767, which is actually a Ford spring, and it is rated at either 344lb or 362lb - because Edelbrock advertises different rates for the same spring depending on which head it is installed!

For what it's worth, I think the [email protected]" and [email protected]" advertised specs for the Ford 429/460 head are closest, as my springs were pretty close to [email protected]" when I removed them - not 120lb.
 
Higher rocker ratios need more spring to control them
 
all great info. i agree with the split in jet size. the only reason the rear is so fat is i added a couple extra degrees of timing 37 total. my trap speeds are around 110 in a 2780lb car on a 28 tall tire. best et so far is an 11.99. my buddy has the exact same set up in a heavier car on street tires and is running 11.7s @ 116 with a 2.0 60.

i think im going to have a cam cut and upgrade springs. its worth the extra 500 bux imo
 
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