Valve spring pressure ?

[Monza355]

I have an older crane camshaft I’m going to use in my sbc engine. It’s part number 118411. I have afr heads with 8mm stem 2.10”1.6” valves and 1.6 ratio shaft rocker arms i plan to run 3/8” pushrod and i would like to be able spin the engine to 7200 rpm.

What spring pressure should i be looking into ?
Here are the specs for the 118411 camshaft

290/306 @.020"
260/268 @.050"
184/183 @.200"
.715”/.688” w. 1.6rr
106 lobe center

Thanks.

[6.50camaro]

In my old Crane catalog they recommend spring # 99886 258lbs@1.950 seat 717lbs@1.250 open 652lbs/in rate or #99885 254lbs@2.050 seat
687lbs@1.280 open 576lbs/in rate. for that camshaft part number. If you need the cam timing @.050 I can give you them also. Dan

[Monza355]

Thanks for the reply. I actually found a card for this camshaft. There they mention the 99985 spring as 215 lbs @ 1.950” and 618 lbs/in spring rate.

But since Crane cams is not around any more these recommended springs are not available. The heads have the standard AFR springs in them 225 lbs seat and 600 lbs at .700” lift. And the AFR upgrade spring is much stiffer and for .800” lift. That would put me too far from coil bind. So i’m not sure thats any better

[bob460]

221443-16 - Manley NexTek Valve Springs

Oval Track/Endurance Valve Springs
1.580'' O.D.
0.832'' I.D.
535 lbs./in. Spring Rate
235 @ 1.950'' Installed
610 @ 1.250'' Open
0.730'' Max Valve Lift
1.170'' Coil Bind
Double Spring (No Damper)

[BOOT]

Solid lifter?

[Monza355]

Solid lifter?

Yes. Solid roller lifter. And small block chev.

[6.50camaro]

Monza,
What is the installed height of the valve, retainer, lock combination you have now?

[rustbucket79]

I would be shocked if the supplied springs aren’t up to the task providing you have sufficient room to bind.

[Monza355]

Monza,
What is the installed height of the valve, retainer, lock combination you have now?

Up to 2” current springs are installed at 1.935” and go to coil bind with the retainer at 1.125” when measured in a wise. AFR says bind is at 1.155”

[Monza355]

I would be shocked if the supplied springs aren’t up to the task providing you have sufficient room to bind.

It’s just the “low” ish seat pressure on these springs that i was concerned about. Everybody on the internet seems to run higher seat pressure. But however These valves are lighter weight with the 8mm stem compared to the standard 11/32” stem

[6.50camaro]

Being right on the edge is tough. If you have titanium retainer, I personally would give them a try on my own motor. If you don't, that is a hard question because the cost of buying ti retainers will go a long way towards new springs. Dan

[Turbobuick6]

Sounds like those heads came with the AFR spring #8000.

Those should be enough for what you are trying to do. If you are nervous about those springs, the PAC-1386 or 1243 would be good candidates that will fit the current hardware.

[Monza355]

Sounds like those heads came with the AFR spring #8000.

Those should be enough for what you are trying to do. If you are nervous about those springs, the PAC-1386 or 1243 would be good candidates that will fit the current hardware.

You’re correct. They are the AFR 8000 springs. How far away from coil bind can they be ran ? And do you know the specs on them diameter vise ? I forgot to measure when i took them apart. But AFR lists the same hardware for 8000 and 8001 spring. Which is the upgrade.

[Turbobuick6]

You’re correct. They are the AFR 8000 springs. How far away from coil bind can they be ran ? And do you know the specs on them diameter vise ? I forgot to measure when i took them apart. But AFR lists the same hardware for 8000 and 8001 spring. Which is the upgrade.

Seeing you are only trying to run 7,200rpm, they would be safe at .150 from bind. Your currently at 0.095" from bind, which I wouldn't even bat an eye.

I personally would try to run the existing springs before making any changes. They should be more than adequate for the job.

IMO the 8001's are way overkill.

AFR 8000
OD - 1.544
ID of Outer - 1.130
ID of Inner - 0.0806
Max Bind - 1.145
Rate 550 lbs/in

AFR 8001 (PAC-1225)
250 @ 2.000"
765 @ 1.200"
OD - 1.550
ID of outer - 1.100
ID of inner - 0.788
Max Bind - 1.150
Rate - 644 lbs/in

[6.50camaro]

Looking at the specs of the spring that Turbobuick6 listed, I might try to find a locator closer to the i.d. of the spring. Spring i.d. .806, locator listed for those heads .780. I have seen a lot worse but .026 is getting loose. I try to stay .010 or under just to keep things from dancing around. no need to invite excessive clearances into the valvetrain. The retainer has .010 clearance on the outer spring and .101 on the inner spring, but you only have to locate 1. The inner spring is not going anywhere if the outer spring is located proper. It's not a major thing that just how I would handle it. Dan