Stock Cam Specs?

[1991_Vn2nV]

Does anyone have the stock cam specs for a series 2 VN V6?

I got some custom grind specs from Crow Cams the other day and I want to compare them with the stock specs but I don't know where to find them?

Also, if anyone knows alot about cam grinds, let me know cause I'd like some opinions on what they suggested... Especially re: overlap as im not sure how to work out how much overlap a cam has...

[88GreenVN]

From the VN/VG Series Service Manual Supplement No 3
1991 3.8 Lt V6 Engine & Associated Components

The std cam has blue paint on one end and a knurl bit for an ID.

Inlet lift 6.43mm, exhaust 6.48mm
valve timming opens btc 31 degrees closes abc 122 deg duration 333 deg.
Exhaust opens bbc 73 deg closes atc 80 deg duration 333 deg

[1991_Vn2nV]

Cheers for the quick reply mate

Didnt make things fall into place in my head like i thought it would tho

[pandaman]

Why don't you post up the cam specs and see if anyone can tell you what it's like comparatively?

[pandaman]

From the VN/VG Series Service Manual Supplement No 3
1991 3.8 Lt V6 Engine & Associated Components

The std cam has blue paint on one end and a knurl bit for an ID.

Inlet lift 6.43mm, exhaust 6.48mm
valve timming opens btc 31 degrees closes abc 122 deg duration 333 deg.
Exhaust opens bbc 73 deg closes atc 80 deg duration 333 deg

You sure on that duration? Stock cam should be somewhere around 260 degrees total duration shuoldn't it?

[88GreenVN]

You sure on that duration? Stock cam should be somewhere around 260 degrees total duration shuoldn't it?

Yep thats what the book has - just had a quick peek 333 Duration (1991 update VN & VG)

[1991_Vn2nV]

Crow Cams suggested this with 1.7:1 rockers:

MODEL TYPE VP V/6 COMMODORE 3800
---------------------------CROW COMPUTER CARD----------------------------
| PART NUMBER 7741515RH L/C 114 Date 21-MAR-07 |
| Cam type: Hydraulic Roller type Profile CUSTOM GRIND |
| ----------------------------------------------------------------------|
| Advance Ground on Cam: 2 Lobe separation: 114 |
| .050 VALVE TIMING |
| Inlet opens: 1 BTDC Closes: 45 ABDC .050 Duration: 226 |
| Exhaust Opens: 51 BBDC Closes: -1 ATDC .050 Duration: 230 |
| ADVERTISED VALVE TIMING |
| Inlet opens: 27 BTDC Closes: 71 ABDC ADV Duration: 278 |
| Exhaust Opens: 77 BBDC Closes: 25 ATDC ADV Duration: 282 |
| Inlet lobe lift at TDC on the over lap: |
| ----------------------------------------------------------------------|
| Valve lift Inlet: .5194 Inlet Rocker Ratio: 1.60 |
| Valve lift Exhaust: .5126 Exhaust Rocker Ratio: 1.60 |
| |
| ----------------------------------------------------------------------|
| RECOMENDED VALVE TRAIN COMPONENTS |
| Valve Springs: Spring height: Collets: |
| Retainers: Pushrod: Lifters: |
| H/D Timing Set: |
| ----------------------------------------------------------------------|

Planning for a raptor supercharger by the end of the year, so I wanna take that into account with the cam, I told Crow and thats what they came up with?

[88GreenVN]

I should get the 3.8L 1988 engine book tomorrow so I will see what the cam specs are for the first of the VN V6's.

[88GreenVN]

The series 1 3.8L book arrived today. The specs are: Inlet open BTC 18 deg, Closes ABC 8 deg 30', Duration 282 deg30'. Exhaust open BBC 64 deg, closes ATC 38 deg 30', Duration 282 deg 30'.

So a big change to the series II v6 cam.

[pandaman]

Crow Cams suggested this with 1.7:1 rockers:

MODEL TYPE VP V/6 COMMODORE 3800
---------------------------CROW COMPUTER CARD----------------------------
| PART NUMBER 7741515RH L/C 114 Date 21-MAR-07 |
| Cam type: Hydraulic Roller type Profile CUSTOM GRIND |
| ----------------------------------------------------------------------|
| Advance Ground on Cam: 2 Lobe separation: 114 |
| .050 VALVE TIMING |
| Inlet opens: 1 BTDC Closes: 45 ABDC .050 Duration: 226 |
| Exhaust Opens: 51 BBDC Closes: -1 ATDC .050 Duration: 230 |
| ADVERTISED VALVE TIMING |
| Inlet opens: 27 BTDC Closes: 71 ABDC ADV Duration: 278 |
| Exhaust Opens: 77 BBDC Closes: 25 ATDC ADV Duration: 282 |
| Inlet lobe lift at TDC on the over lap: |
| ----------------------------------------------------------------------|
| Valve lift Inlet: .5194 Inlet Rocker Ratio: 1.60 |
| Valve lift Exhaust: .5126 Exhaust Rocker Ratio: 1.60 |
| |
| ----------------------------------------------------------------------|
| RECOMENDED VALVE TRAIN COMPONENTS |
| Valve Springs: Spring height: Collets: |
| Retainers: Pushrod: Lifters: |
| H/D Timing Set: |
| ----------------------------------------------------------------------|

Planning for a raptor supercharger by the end of the year, so I wanna take that into account with the cam, I told Crow and thats what they came up with?

That's a fairly big cam (by my standards anyway, by performance standards it's still fairly mild), you'd be wanting good quality valvetrain to go with it. Probably nothing crazily expensive though. It makes pretty good sense as a forced induction cam, wide lobe spacing, slightly longer exhaust duration. Fair bit of lift though, with the 1.7 rockers you're looking at over .550 valve lift, might wanna look into what springs would be suitable for that. If you're running that naturally aspirated on stock compression until you get the charger on, it'll probably be pretty doughy down low.

[pandaman]

The series 1 3.8L book arrived today. The specs are: Inlet open BTC 18 deg, Closes ABC 8 deg 30', Duration 282 deg30'. Exhaust open BBC 64 deg, closes ATC 38 deg 30', Duration 282 deg 30'.

So a big change to the series II v6 cam.

Those inlet timings don't add up, it gives a duration of 206 not 282. They the .050 or .075 timings or something?

From the VN/VG Series Service Manual Supplement No 3
1991 3.8 Lt V6 Engine & Associated Components

The std cam has blue paint on one end and a knurl bit for an ID.

Inlet lift 6.43mm, exhaust 6.48mm
valve timming opens btc 31 degrees closes abc 122 deg duration 333 deg.
Exhaust opens bbc 73 deg closes atc 80 deg duration 333 deg

I still reckon there's something fishy going on there, the crow base model, standard replacement type cam has adv. durations of 262 inlet and 264 exhaust. Lobe lift's are reasonable though. The biggest off the shelf cams out there have durations just over 300. So I'm not sure what those figures refer to, but it's not cam timing as I know it.

[88GreenVN]

OK out with the camera...... That should fix the issue...

[88GreenVN]

Here are the 2 pages.

[pandaman]

OK out with the camera...... That should fix the issue...

Well no, it doesn't really fix it. 18+180+8.5 = 206.5 not 282.5, so unless I'm missing something, at least one of the figures in that book is very wrong. The 333 duration cam in the S1 is also highly suspect given that no aftermarket manufacturer comes close to having anything with that duration off the shelf.

lol, took me a while to figure out what 30' means, they're using minutes. Haven't seen that notation used in years. Good stuff!

[88GreenVN]

Well no, it doesn't really fix it. 18+180+8.5 = 206.5 not 282.5, so unless I'm missing something, at least one of the figures in that book is very wrong. The 333 duration cam in the S1 is also highly suspect given that no aftermarket manufacturer comes close to having anything with that duration off the shelf.

lol, took me a while to figure out what 30' means, they're using minutes. Haven't seen that notation used in years. Good stuff!

Well the book could be wrong - Dont know much about cams - thats why I purchased the books! AND they are wrong - Wish I had my Gregorys of the 3.8 still. Gone missing bugger it.

[1991_Vn2nV]

Hey Pandaman, would you suggest Crow Cams or Wade Cams? As im not sure which brand to go with...

I was set on Wade, but Crow Cams replied to my email whilst Wade Cams have not (over a week).

[pandaman]

Hey Pandaman, would you suggest Crow Cams or Wade Cams? As im not sure which brand to go with...

I was set on Wade, but Crow Cams replied to my email whilst Wade Cams have not (over a week).

I've met a few fellas who've used wade cams in ford 6's with great results. Dunno about holden 6's though. I'm running a crow cam in my 5L and have no complaints. Either way you'll probably do ok as long as you research and design your combo carefully and don't take shortcuts on the assembly. Some people say crow are a cheap and nasty solution, but realistically that could just be because of the huge volume of crow stuff out there.

[pandaman]

im not sure how to work out how much overlap a cam has...

Dammit, I'm bored and I can't sleep because of the rediculous amount of caffeine I've consumed. So I'll go through how to calculate overlap for ya. Overlap is simply the amount of degrees of crank rotation where both the inlet and exhaust valves are open.

Crow Cams suggested this with 1.7:1 rockers:

MODEL TYPE VP V/6 COMMODORE 3800
---------------------------CROW COMPUTER CARD----------------------------
| PART NUMBER 7741515RH L/C 114 Date 21-MAR-07 |
| Cam type: Hydraulic Roller type Profile CUSTOM GRIND |
| ----------------------------------------------------------------------|
| Advance Ground on Cam: 2 Lobe separation: 114 |
| .050 VALVE TIMING |
| Inlet opens: 1 BTDC Closes: 45 ABDC .050 Duration: 226 |
| Exhaust Opens: 51 BBDC Closes: -1 ATDC .050 Duration: 230 |
| ADVERTISED VALVE TIMING |
| Inlet opens: 27 BTDC Closes: 71 ABDC ADV Duration: 278 |
| Exhaust Opens: 77 BBDC Closes: 25 ATDC ADV Duration: 282 |
| Inlet lobe lift at TDC on the over lap: |
| ----------------------------------------------------------------------|
| Valve lift Inlet: .5194 Inlet Rocker Ratio: 1.60 |
| Valve lift Exhaust: .5126 Exhaust Rocker Ratio: 1.60 |
| |
| ----------------------------------------------------------------------|
| RECOMENDED VALVE TRAIN COMPONENTS |
| Valve Springs: Spring height: Collets: |
| Retainers: Pushrod: Lifters: |
| H/D Timing Set: |
| ----------------------------------------------------------------------|

So for this cam, the exhaust opens 77 degrees before bottom dead center and the inlet valve closes 71 degrees after bottom dead center. Add those two together and you get the total duration where both are open. In this case 148 degrees. That's total overlap. For some of that though the valve opening is bugger all. That's why figures for 0.050 duration are supplied, 0.050inches is generally accepted as the lift figure where meaningful airflow begins to get past the valve. (some people use 0.075 as well) So take your .050 exhaust opening and inlet closing, and you get 96 degrees meaningful overlap. Be careful when asking a company what overlap a cam has, as different companies will supply overlap calculated in using different lift points. Best to do it yourself from the spec sheet probably.

Just as a comparision, the crow4001 I'm using has 260 degrees total duration, 206 degrees 0.050 duration. 114 total overlap and 70 degrees meaningful overlap. All that can be easily calculated from the valve timing figures. Understanding what that means in terms of how it will perform in an engine is an entirely different matter though, which I'm happy to leave to the experts.

[greenfoam]

VN2NV, Wade are a old fashioned kinda company I bet they are still down the machine shop grinding cams with an old oil stained phone with a dial on it I don't think they would be into emails but they can make good cams so ring them up