383 Valve spring pressure on heads?

Rustymopar · May 4, 2015

I'm having my heads planed, ported and polished.
The machinist measured something on the springs and then used some kind of pressure testing device.
He started questioning the engine builder who built the motor. He said the valve springs should be at 140-150 and they were at 190 and I'm risking tearing up the cam.
Does anyone know for sure where they should be? The heads are standard cast iron for my 383 HP . I have a cal linto the builder but he's not the most responsive.

Banzaiii67 · May 4, 2015

What cam do you have? At 1.88 installed height you should be closer to 115-130 on the seat if using single spring or 140-150 with dual valve spring. Its cam dependant though, more lift requires stiffer valve springs.

Meep-Meep · May 4, 2015

190 on the seat is insane for anything but a very radical solid or roller cam. Even 140-150 is too high for a stock cam but about right for a mild performance cam. Open pressure with a hydraulic lifter shouldn't be much more than 350 PSI.

Rustymopar · May 5, 2015

509 Lift cam. Double springs...

Meep-Meep · May 5, 2015

I'd say 190 on the seat is still way too much for the .509" cam. 140-ish lbs seat and maybe max 400 open.

Rustymopar · May 6, 2015

That's exactly what Comp cams said. Springs are getting changed today.

The Horvaths · May 6, 2015

Good catch!
What lifters do you have planned for it?

Rustymopar · May 7, 2015

The Horvaths said:
Good catch!
What lifters do you have planned for it?

I believe they were Comp Cams lifters (not 100 % sure). They were already in there.

383 Valve spring pressure on heads?

Rustymopar

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Banzaiii67

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Meep-Meep

дворянин

Rustymopar

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Meep-Meep

дворянин

Rustymopar

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The Horvaths

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Rustymopar

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