Detailed specifications for the 292 .509" P4120237AE cam

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mhuppertz

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While I am still gathering parts and horsetrading to get my 440 up and running I am punching in the numbers for my engine in Desktop Dyno, and I can't find the detailed cam specs for the old .509 cam. I need valve opening and closing events.
Looked in all my ancient Mopar engine manuals and old parts catalogs, all I can find is the basic stuff, .509" 292, 108 248 at .050, 76 degrees overlap.

Anybody have these anywhere?
 
You make them up: all you need are the two durations and the LSA

With a 108 cam
First you figure the overlap, thus
Duration intake plus duration exhaust, totaled and divided by two, from that subtract double the LSA; So (292+292)/2 less (2X108) =76*
Next you allocate half of that to each each duration, so 76/2=38.
And there you have your first spec; Intake opens at 38 BTDC
Next bear in mind that all the events have to occur in 2 engine revolutions so 720*.
And the events are intake,compression,power and exhaust,and scavenging
So then we subtract those 38* from the 292 and whatever is left has to add up to 360. So 360less (292-38)=106* for compression. That is 106 from top dead center so 180less 106=74* after bottom. So there is your second spec; intake closes at 74 ABDC.
Since this is a single pattern cam, the other side is identical. This would be an install of straight up, or 108*
Nobody runs this cam straight up.
In a small block on the street, Rusty recommends an install of 100*. In a 440 with enough compression, 104 might be the place to be. This means all the events have to be advanced to:108 less 105=4 degrees
And that makes the events 42,70,78,and 34
Ok I'll fill in the blanks
Intake opens at 42 before top, closes at 70 after bottom
Exhaust opens at 78 before bottom,closes at 34 after top
From this; you can see the overlap events are offset 4 degrees as well ,but the split is now 42 to the intake versus 34 to the exhaust.

While you are in the desktop, try this one; the 284/292/108 in straight up. The events are 36-68-76-36
Intake opens 36 before top closes 68 after bottom
Exhaust opens 76 before bottom, closed 36 after top
 
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Wow, thanks!
I am equally impressed and humbled... I have a "racecar" math book, but it doesn't have that in it.

I installed a 292 cam in a 383 (in the 80's) straight up and I loved the hit at about 2,800 rpm. I could barely keep traction after 3k, and that was in a '74 'Cuda. The problem I had was the converter was too tight so I had serious lag until it "got up on the pipe" and ripped.

The 440 I am building is going into my '69 Dart with an A833, and low end torque will be a problem with a car that light and front heavy, so I am actually installing this one straight up too. I want that insane mid and top end this cam produces with a Torker and stepped, pro parts style stepped headers without having to feather it out of the hole. Rev and dump!

Who is Rusty?

Thanks for this info. Very helpful!!!

AJ/FormS said:
You make them up: all you need are the two durations and the LSA

With a 108 cam
First you figure the overlap, thus
Duration intake plus duration exhaust, totaled and divided by two, from that subtract double the LSA; So (292+292)/2 less (2X108) =76*
Next you allocate half of that to each each duration, so 76/2=38.
And there you have your first spec; Intake opens at 38 BTDC
Next bear in mind that all the events have to occur in 2 engine revolutions so 720*.
And the events are intake,compression,power and exhaust,and scavenging
So then we subtract those 38* from the 292 and whatever is left has to add up to 360. So 360less (292-38)=106* for compression. That is 106 from top dead center so 180less 106=74* after bottom. So there is your second spec; intake closes at 74 ABDC.
Since this is a single pattern cam, the other side is identical. This would be an install of straight up, or 108*
Nobody runs this cam straight up.
In a small block on the street, Rusty recommends an install of 100*. In a 440 with enough compression, 104 might be the place to be. This means all the events have to be advanced to:108 less 105=4 degrees
And that makes the events 42,70,78,and 34
Ok I'll fill in the blanks
Intake opens at 42 before top, closes at 70 after bottom
Exhaust opens at 78 before bottom,closes at 34 after top
From this; you can see the overlap events are offset 4 degrees as well ,but the split is now 42 to the intake versus 34 to the exhaust.

While you are in the desktop, try this one; the 284/292/108 in straight up. The events are 36-68-76-36
Intake opens 36 before top closes 68 after bottom
Exhaust opens 76 before bottom, closed 36 after top
Click to expand...

20170712_203456a.jpg
 
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Rusty is RRR here on FABO; an old timer like me but with vastly more experience, and a great guy.
Yeah I had that 292/108 in my 367 for a time at 11.3Scr ,and the hit was sweet ............but with 3.55s and an 833, in second gear, the hit didn't come around until 60 mph, not the greatest combo for the street I thought. I ditched that cam before the summer was out.
I'm pretty sure the hit of that cam stems from the 108 LSA, and some day I hope to get a smaller, more street-friendly cam, perhaps on a 106 or 104LSA, to see if I'm right.
In a BB, that 292 should peak a little sooner, so it may be better. I was much happier with a much smaller cam.
The 484 cam I mentioned has similar timing to the 292 but the overlap period is not crossed up, like the 292 is at 104ICL or worse at 100*. I just wondered how it would compare in power as I'm sure it would be more streetable.I know it would be easier on gas, and that might become important in the near future.
But the 292 is a great drag cam, with a well-matched combo.
 
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