442 83/84 H/O and 85 442 Cam Specifications

[69hurstolds]

I couldn't find any real specifics on the Olds VIN 9 camshafts for the flat-tappet 307s. So I decided why not just put it in one spot so it may be easier to find. Just in case anyone is looking for it for whatever reason.

Cam specs for the Olds VIN 9 cam are as follows (likely roller specs):
Advertised duration: intake 256, exhaust 268
Duration @ .050: intake 194, exhaust 210
Lobe seperation: 109
Intake centerline: 112
Lift at cam: intake .272", exhaust .274"
Lift at valve: intake .435", exhaust .438"
Timing @ .050" lift:Intake opens 15 ATDC, closes 29 ABDC
exhaust opens 31BBDC, closes 1BTDC


Found this on another site.
0.440/0.440 lift 196/208 @0.050 lift 109LSA for 83-85
256/270 109LSA
0.435/0.438 194/210 0.050 lift 109LSA for 86-90

Additionally, about the only close aftermarket cam that meets these specs are the Sealed Power CS-651 cam. Those specs I can find are as follows:
Lift at valve: intake .440", exhaust .442"
Duration @ .050: intake 194, exhaust 207
Lobe separation: 109

Keep in mind, these are computer cams. Can you get and use a bigger cam? Sure. Will it work with the computer? Try it and see. There is a limit as to what the computer can handle, but not sure where that limit is.

I can tell you the CS-651 will not kill your computer should you use it. I haven't used any others.

Valve Springs:
83-'90 VIN 9: GM# 22510372. These springs are also found in the Olds V8 diesels of the era, roller cam or flat-tappet, makes no difference. Specs below.

Spring Pressure @ 1.270": VIN9 203-217 lbs, the VINY 180-194 lbs.
Spring Pressure @ 1.670": VIN9 85-95 lbs, the VINY 76-84 lbs.
Spring free length: VIN9 2.090", the VINY 1.960"

Pushrod Length: 8.265" flat-tappet hyd. / 7.718" for the roller

 

[olds307 and 403]

I thought that the top cam was the roller cam 307 HO specs? The CS-651, I thought that was the flat tappet cam 307 HO specs? If those aren't right, what are the roller cam specs? I tell you even the 204/214 cam is borderline with the 94 TBI sbc 350 computer with an Olds 350. Guys have ran more with CCC computer, the Vin 9 seems much more tolerant than the Vin Y ECM.

 

[69hurstolds]

It's very possible. I was simply collecting the information up to try and locate it in one spot here, but you could be right. Those specs were right next to the picture of the flat-tappet cam, so I simply assumed the information was for the flat-tappet cam. I've seen nothing definitive about the 86-90 VIN 9 roller cam, but I'm imagining they wouldn't be too far off the mark of the flat-tappet.

The lift specs on the roller VIN 9 cam is .272/.274 listed in the CSM, which with a stock 1.6 ratio puts it at .435" and .438" lift at the valve. That matches what is above. I just checked the CSM for the 85 VIN 9 and the lift specs there are .275/.275 (.440" at the valves). Again, not much difference but it is different, nonetheless.

Seems like the cam specs are likely very close to each other regardless.