CAM SELECTION OPINIONS

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CFD244

CFD244

"I LOST MY ID IN A FLOOD"
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Hi Folks

Here it is....

1971 Demon 340 Automatic (mild shift kit) with P/S and P/B
Engine is .040 over with a stock steel crank.
Heads are O heads with 2.02's and are 68 cc's (fresh from the shop)
273 Adjustable rockers with hydraulic lifters.
1969 HP Manifolds
Factory Intake and T/Q
Using reduced compression height pistons to reduce detonation (.002 into the chamber)
Static compression calculates to 9.17:1 with .040 gasket.
Quench is impossible.
Plan on using a 2400 stall with 3.23 gears
Looking for a punchy cruiser that will never see the track.

I have 2 cams in my possession and am not sure which would be best for my application.

#1. Comp Cams XE262H. With the valve timing events puts me at 7.71 Dynamic
#2 Lunati Voo Doo 268. With the valve timing events putting me at 7.86 Dymanic.

What say you all? pro's/Cons?

Thanks
 
#1 with that stall and 3.23 gear. The Lunati Voo Doo 268 wants more converter and a 3.55.
 
How do you figure that?

262 vs 268 seat to seat, both installed at 106 puts the 262 IVC point 3deg earlier.
 
What does the cam card list the closing at on the 268 Lunati cam? The Wallace calculator shows 60 degrees closing on it, and comp lists their XE 262 to have an intake closing of 57 degrees. The Wallace calculator also shows 57 degrees closing on the comp cam.
 
PRH said:
How do you figure that?

262 vs 268 seat to seat, both installed at 106 puts the 262 IVC point 3deg earlier.
Click to expand...
I just read the info from the respective cam cards, and punched that info into the Wallace compression calculator. Info was installed at 106 for both cams.
 
Garrett Ellison said:
What does the cam card list the closing at on the 268 Lunati cam? The Wallace calculator shows 60 degrees closing on it, and comp lists their XE 262 to have an intake closing of 57 degrees. The Wallace calculator also shows 57 degrees closing on the comp cam.
Click to expand...
Lunati says closing at 39. That must be @.050 so the calculator prompts to add 15 to that number. Adds up to 54.

Edit: I used a different calculator since the Wallace did not make reference to the .050.
 
If you look at the cam card for the Lunati, you’ll see that “268” advertised duration is actually 271 degrees.

Which puts the IVC point at 61.5ABDC....... or 4.5deg later than the 262 cam.

2175A088-E1ED-4EE4-9592-EEA98A89C8CB.jpeg


The 39deg closing point is at .050 tappet lift, which is not where the valve closes.
With a 1.5 rocker, the valve would theoretically still be .075” away from being closed at that point.

With a hyd profile, the .050 closing point + 15 degrees will almost always steer you wrong.
 
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I e been waiting 5 months for my Howard’s HFT.
I canceled the order.
 
I searched a few different numbers...... a couple were available at Summit.

At this point in time, I wouldn’t hold out for any SBM cam that someone didn’t have in stock.
The less than perfect cam is still better than no cam.

Edit- I missed the part where the OP has two cams already.
He’s good to go.
 
Well...... I’ve never put a Voodoo cam in anything...... so I’d give it a try.
 
I ran that same voodoo cam he has listed in a 360/904 2400 stall and a 3.55 gear. I pulled the transmission and put a 3400 stall in it. It needs more than 2400.
 
You’re probably right.

Plus....... I’m not sure the TQ’s low speed operation would be great with the bigger cam.
 
I would be SURE of those dynamic numbers. That said, I like the Lunati. It "should" have a lower dynamic than the Comp.
 
When I run the numbers for the Lunati thru the Wallace calculator I get 7.49 dynamic....... and 149psi on the gauge(at sea level).

The Comp 262 shows 7.73 dynamic and 156psi on the gauge.
 
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I've got to go with the XE262 as well. I've known of it to work in a lot worse than that combination with satisfactory results.
 
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