Moparts
SPRING PRESSURE ON MOPAR .590 CAM
Posted By: deaks
SPRING PRESSURE ON MOPAR .590 CAM - 04/07/10 10:37 PM
i have got RPM springs with inners for my old motor which had a R280 roller cam, is this too much and if so, will the RPM springs without the inners be sufficent.
Mick
Posted By: maximum entropy
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/07/10 10:56 PM
that would be too much with the inners imo. that cam is next on my list, and i'm going to run it with a fresh set of rpm springs. i've had very good luck with those springs on similar cams.
Posted By: 440Jim
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/08/10 01:25 AM
Depending on valve train weights (including valves), and desired RPM, roughly 135 lbs seat and 370 lbs open is in the ball park.
Posted By: ProSport
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/08/10 01:27 AM
I ran the Isky 8005a springs with the 590 cam with good luck, also used 1.6 rockers.
Posted By: Dunnuck Racing
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/08/10 01:43 AM
We run Comp #928 springs with that cam,using the stock Edelbrock installed height.The are a direct swap for the stock Edelbrock springs.It is a good idea to upgrade the retainers and locks,but you probably already did with a roller?
Posted By: deaks
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/08/10 09:30 PM
I've just checked the springs they are 190 seat, stock eddy valves, isky 1.5 solid rockers.
I dont really want to buy another set as i also need new push rods, a converter and a new set of slicks and the money is running out.
I've got a spare set of brand new stock eddy springs, they claim they are good to .600 lift on their website.
Jim
I will shift at 6200 and maybe 6700 or so through the 1/4 mile.
prosport
I cant find them on isky's website, do you know what spring pressure they are.
Mick
4.56 gears and 31" slicks.
Mick
Posted By: 440Jim
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 12:40 AM
Quote:
I've just checked the springs they are 190 seat, stock eddy valves, isky 1.5 solid rockers.
I dont really want to buy another set as i also need new push rods, a converter and a new set of slicks and the money is running out.
I've got a spare set of brand new stock eddy springs, they claim they are good to .600 lift on their website.
Jim
I will shift at 6200 and maybe 6700 or so through the 1/4 mile.
prosport
I cant find them on isky's website, do you know what spring pressure they are.
Mick
4.56 gears and 31" slicks.
Mick
IMO, the springs you have will risk wiping the solid lifter cam. With only 6700, you might be fine with 340 open, but I still like 130-140 seat.
Posted By: 493_DART
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 01:03 AM
Quote:
I ran the Isky 8005a springs with the 590 cam with good luck, also used 1.6 rockers.
thats what i use. i think they are about 400lbs open .
Posted By: Von
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 02:29 AM
Quote:
Quote:
I ran the Isky 8005a springs with the 590 cam with good luck, also used 1.6 rockers.
thats what i use. i think they are about 400lbs open .
I have them also. But, I dont think they are near 400 open, more like 330-350.
Looks like they are 135 on the seat at 1.875. 
Posted By: 440Jim
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 03:18 PM
From Isky web site:
http://www.iskycams.com/springbook.pdf125 at 1.900"
145 at 1.850"
So at 1.88" that would be about 133 lbs seat
And at 0.590" lift from 1.88, ie 1.29" open
365 at 1.300"
385 at 1.250"
So at 1.29" that would be about 361 lbs open
Posted By: deaks
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 06:49 PM
I'm going to try the edelbrock singles, i currently run 29.5 slicks with a 4.56 gear but I'm fitting 31" slicks to keep the revs down a little.
Posted By: Cab_Burge
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 07:10 PM
Mick, check the open pressures(all of them) on those roller springs. I would break in the cam in with the Eddy springs and then, if the open pressues is not over 400 lbs, swap the roller springs into the motor. I run 165 to 190 lbs. on the seats and shoot for 375 to 425 lbs open, but you should absolutely break the new cam in with less pressures
Posted By: deaks
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 07:51 PM
HI Cab
The cam is already broken in and the heavier springs are still on at the moment, i've just clayed the heads again and the clearance seems ok, just need some longer puhrods and i will finish putting it together.
I've also got a .625 herbert roller i might try later, just want to try the .590 first to see if it deserves it's reputation.
Mick
Posted By: Cab_Burge
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 07:54 PM
Quote:
just want to try the .590 first to see if it deserves it's reputation.
Mick
Good luck 
Mick, is this one of the early "590" with .590 net lift at the retainers with the lash set or one of the later ones that doesn't have .590 net lift at the retainers?
Posted By: deaks
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/09/10 08:58 PM
I dont know Cab, i didn't realise there was more than one.
Jim
Thanks for the info.
Mick
Posted By: 572B1
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/10/10 11:59 AM
Crane dual springs, eight years of street and strip. bullet proof.
Posted By: 440Jim
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/10/10 01:17 PM
Quote:
I'm going to try the edelbrock singles,
What pressures do your springs measure? I have seen people report significantly different values over the years. So, maybe Edelbrock changed springs at some point.
Posted By: deaks
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/10/10 07:12 PM
I have nothing to measure them pressure wise but the eddy site claims they are good up to .600 lift, so rather than wipe the cam i'll try them and if they dont work out, i'll get my wallet out again.
Mick
Posted By: 440Jim
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/11/10 04:47 PM
I think if you took them to a shop to measure the Edelbrock RPM valve spring pressures, they would be around 120 seat (1.88). I can't guess at the spring rate and open pressure.
But like I said, many reported differences over the years. The danger with too little spring pressure is valve float and the resulting valve train damage. It could be mild, or could ruin the valve seat sealing, bend pushrods, break rockers, not to mention weaken the springs. If a retainer or locks(keepers) let go, it could swallow a valve. I would be careful.
Posted By: deaks
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/11/10 05:40 PM
Thanks Jim
I still have to buy pushrods, new slicks and a converter yet, so money is getting a little tight.
I will try it with the 6500 chip first, shift at 6200.
If work picks up a little more, then i'll buy the springs sooner.
Mick
Posted By: cbarracuda
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/11/10 05:48 PM
Quote:
i have got RPM springs with inners for my old motor which had a R280 roller cam, is this too much and if so, will the RPM springs without the inners be sufficent.
Mick
Isky 8005 is best installed at 1.90, the rpm are also good installed at 2.00"
Posted By: Sport440
Re: SPRING PRESSURE ON MOPAR .590 CAM - 04/11/10 07:23 PM
Quote:
I have nothing to measure them pressure wise but the eddy site claims they are good up to .600 lift, so rather than wipe the cam i'll try them and if they dont work out, i'll get my wallet out again.
Mick
My Eldelbrock headsheet rates the EDDY RPM springs 120 lbs @ 1.88 ht.
Back in 06 Dwayne Porter measured some of my Hughes springs and for Comparison he sent me the measurements on a New Eddy RPM spring, they were;
127 lbs @ 1.900
140 lbs @ 1.860
297 lbs @ 1.400
330 lbs @ 1.300 mike