how much valve spring psi?

[blownzoom440]

i need to change my springs with running more boost.
how much more psi do i need?
1.88 install height[1.9w/shim .020]
1.0 width double with damper,.700 inside diamater.
2.14 Stainless valve.3.2sq in area.
14lbs of boost
6800 rpm
the prior spring had 180psi seat,300psi open at .550 lift with 8lbs of boost.
sorry if i forgot any info.just ask if so.
thanks for any help!!
i was looking at the comp 938 w/480lbs in.
bind at 1.225"
i think it gives me 220lbs on the seat.
http://board.moparts.org/ubbthreads/download.php?Number=2822511

[gn7]

basically you take the sq. of the valve and multiply by the boost, and that is how much more spring you need. My calcs say your valve has 3.59 sq. in which means you 59 more lbs. I'd say 40 is close enough and with a flat tappet you don't want to go over board and flat'n da cam

[Fiat48]

I assume this is a roller cam?

[blownzoom440]

I assume this is a roller cam?
no it iis a solid tappit.252/260 at .050 .541/.559 lift comp cam.i was thinking about the cam taking more spring psi is it was gunna be real bad for it.:confused:

[gn7]

no it iis a solid tappit.252/260 at .050 .541/.559 lift comp cam.i was thinking about the cam taking more spring psi is it was gunna be real bad for it.:confused:
At that spring pressure the chances of your surviving are about nil. get your self some comp. barrel springs for a big block and be happy, but with that kind of boost I would think that you were running some full boat deal

[steelcomp]

Time for a roller. You can't have your cake and eat it too.

[DetroitJim]

Yikes! comp 938's will kill your cam. 204 lbs. at 1.900 is roller territory. I'm surprised you haven't wiped your cam already if you have 180 lbs. now.

[blownzoom440]

At that spring pressure the chances of your surviving are about nil. get your self some comp. barrel springs for a big block and be happy, but with that kind of boost I would think that you were running some full boat deal
i am not aware of barrel springs!?
do you have a part #?
i will call comp to check the max psi thay allow for spring psi.
thanks for the help so far!!!!

[blownzoom440]

so thay said what i have is the max at 180# seat psi.i had to check to be able to compare to.
i must be getting spark crossfire in the cap or have bad plug wires.
the engine is not firing all the time and shook the car on the chassis dyno.i believe it is effecting all cylinders because when i took it apart to upgrade the crank all the chambers/pistons looked the same[good condition]AH HELL!:confused: :(
it is a long story to tell getting where i am now with this.8 lbs and up she no workie as soon as you hit the gas!!!
.020 plug gap NGK #8
7AL-2 MSD/pro coil,billet distr.

[DetroitJim]

Go through your entire ignition, check for arcing or plug wires. i would open up the plug gaps, 0.040 to 0.050 is fine for an MSD. Also check all of your ground wires back to the battery. if you are going through any anodized aluminum to get there, it can cause a problem.

[blownzoom440]

thanks!
i closed the gap to eliminate that.most boosted engines on yellowbullet.com closing the gaps to .025.
my plug wires may be a source and were getting replace also on the list.
i will check the grounds and wires going to the battery.i do go thru aluminum where the rear seat was.
thanks again.

[blownzoom440]

here is a cam i am looking to comp cam solid roller
.600 int/.630 exh
258/268 at .050 dur.
.050 ivo 31/ivc 63
evo 77/evc 29
seat to seat#
ivo 16.5/ivc 62.5
evo 67/evc 21
overlap 37.5
113LSA true ICA 110 int/ECA 115
spring 943-16 240# seat/551# at 1.150 bind[i think]
829-16 lifters.

[blownzoom440]

my old spring psi was only 100# seat as i found yesterday thay lost a lot of psi running them.so sorry to bather you guys with my confusion.i should still go with the roller though.
thanks.

[Fiat48]

Well I rather suspected as I know of no flat tappet cam that survived 180 lbs on the seat. Thought maybe you had the first.
Yes..Roller....do it now. Perhaps you can recoup some cost by selling your still good flat tappet and related parts.

[mach1alaska]

there is a great deal on a good roller cam and lifters in the spam section under" big block chevy heads"