82Waggy Ordered His Cam

[82Waggy]

Well, I finally pulled the trigger and put my money where my mouth is.

I ordered the following custom grind for my 401 from Engle through the machine shop I've been using.

Lobes, Engle K52H Int, K54H Exh
Rocker Ratio,1.6
LSA,112
Int. Duration@.006,254
Exh. Duration@.006,260
Int. Duration@.050,209
Exh. Duration@.050,214
Intake Valve Lift,488
Exhaust Valve Lift,501
Overlap,33
Hydraulic Intensity,45

I chose this cam to make power in my rpm range with my setup. With my gearing I will not likely be exceeding 4000rpm very often, if ever, and I am looking for a flat curve with good off idle grunt.

This is my first best guess at acheiving my goals, all things considered.

[Blown7]

I doubt your going to Dyno it,
(In my best The Shadow voice)
"But only the dyno would know for sure."



BTW what is hydraulic intensity?

Jeff

[82Waggy]

I doubt your going to Dyno it,
(In my best The Shadow voice)
"But only the dyno would know for sure."



BTW what is hydraulic intensity?

Jeff

Might dyno it. Not ready to commit to that yet though and would need to come up with a bellhousing.


"Hydraulic Intensity" (as defined by Harvey Crane):

The ideal cam profile would raise the valves to full lift instantly, hold them open for a specified duration and then close them instantly. The laws of physics make it impossible to achieve instantaneous valve opening and closing, but recent advancements in design technology have made it possible to open and close the valves with more area under the lift curve. By so doing, engine efficiency is improved because the valves spend less time at very low lift.

Hydraulic Intensity may be computed by subtracting duration at .050" tappet lift from duration at .006" tappet lift. A lower number translates to more low end power, without any loss of top end power, and solves many complaints of poor idle quality. It also means it may be practical to install a cam with slightly longer duration at .050" cam lift than might otherwise be practical.

In practical terms, if two cams have the same duration at .050" lift, maximum torque and horsepower will be almost identical. However, the cam with the smaller Hydraulic Intensity figure will have a smoother idle, better off-idle response, superior low speed drive-ability, and a broader power curve.

PS: Nice thing about AMC engines is their big diameter lifters to take max advantage of this.

[Blown7]

AHHHHHHHHHH
Thanks

Jeff

[1980_Cj7]

BTW what is hydraulic intensity?

Jeff

And here all this time I was thinking "hydraulic intensity" was when you had to go real bad.

[82Waggy]

And here all this time I was thinking "hydraulic intensity" was when you had to go real bad.

It's when you have to go real fast!

[82Waggy]

Got my cam:



Seems to be properly configured with grooved front journal and rear oil relief holes.

Now if my Rollmaster timing set would show up I'll check oil path alignment of all the front end components and start putting this thing together.

[fifesjeep]

That's a healthy looking cam spec card... What are your intentions with this motor?

[82Waggy]

That's a healthy looking cam spec card... What are your intentions with this motor?

Max torque off idle to 4000rpm

[fifesjeep]

That's a healthy looking cam spec card... What are your intentions with this motor?

Max torque off idle to 4000rpm

I guess I could've read the opening post... What all are you doing to this motor?