Valve Spring Installed Height and Pressure

[ChristianCuda]

Guys big question I hope you all can answer quickly.
My Machinist is setting the installed height on my valves. The valves I am using are the MP#p3690933 Single with dampner. I told him1.85 installed height but that is giving less than 100lbs of closed load pressure. What are the pressure supposed to be on these springs. I have heard that it should be anywhere between 105 and 120 lbs.

Please Help quick. All I need to get the car to Mopar night are the heads back from the machine shop. I need to blow away a few Rustangs and slomaros.

PS car is 68 Curious yellow Barracuda Fastback with
383 ported heads 2.08 in and 1.81 ex
10.5:1 measured Compression
Balanced and lightened rotating assembly
509"/292 MP Purpleshaft
Weiand 7741 Single Plane with
750 Holley Vacuum Sec.
or 830 Holley DP
8 3/4 w/3.91 cone sure grip
super stock springs and snubber

Thanks Christian


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68 'Cuda 383 Working on adding EFI
69 'Cuda Race Parts Car
76 Duster 273 recent transplant
95 Neon 2.0 SOHC best of 16.96
84 Dodge Ram D50 transplanting 360

[340king]

The required spring pressure is normally a function of the cam lobe design. Different lobes require different seat pressures. What I have seen for average seat pressures is from 120-150 lbs. This is for a solid lifter camshaft. The cam card should show or give a suggested seat pressure. If not I would shoot for near the 120 lb range and check it at open also. I would stay at or below the 300 lb mark at max lift for a street driven vehicle to reduce heat build up and wear on the valve train. There may be some other considerations, I don't know much about the the cam.

[ChristianCuda]

Thanks 340king
He has them set at 1.85 height with 115lbs pressure. I think this will work fine.

Christian

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68 'Cuda 383 Working on adding EFI
69 'Cuda Race Parts Car
76 Duster 273 recent transplant
95 Neon 2.0 SOHC best of 16.96
84 Dodge Ram D50 transplanting 360