Stock Magnum cam, is it 228-241 duration or 213-225 duration?

[DeuceCoupe]

Hi, I am new here and searching for engine data.
Most of the places I see say that the stock cam for:
383/335 Magnum
440/375 Magnum
440/390 6v
was all the same cam, 1967-1971, manual or automatic.

Most places I see give the duration at .050 lobe as
228-241
Lift .450 .458

Is that true for all years?

But Clevite shows another cam for "383 & 440", CLV-2323,
383 4bbl 1968-1971
440hp 1968-1978
With a duration of
213-225
Lift .447 .459
That is quite a bit smaller, but the lifts are so close I am confused, are the 213-225 and the 228-241 the same cam? If so, who is right?
Where was this smaller cam actually used?
I'm guessing maybe on the 1972-up 440hp for smog?
Anywhere else?

Thanks very much, I tend to shy away from "advertised" durations as they are often arbitrary.
:brickwall:

 

[droptop]

383-4 hp and 440-4 hp used the same cam. 440-6 had it's own cam. For '69 any way. Not sure about other years.

268/284 Duration, 0.450"/0.458" lift, 46 degrees overlap (115 LSA), installed at 113 Intake CL. is the 383 - 440 hp cam specs.

 

[Tempest 455]

The notes I have on the factory cam are:

Intake Duration, Nominal 268° Exhaust Duration, Nominal 284°
Intake Duration @ .050” 208° Exhaust Duration @ .050” 221°
Intake Lobe Centerline 113° ATDC Exhaust Lobe Centerline 117° BTDC
Lobe Separation Angle 115° Overlap 46°
Intake Opens 21° BTDC Exhaust Opens 79° BBDC
Intake Closes 67° ABDC Exhaust Closes 25° ATDC
Intake Lift .450” Exhaust Lift .458"
Note: original 440, Commando, 383 Magnum etc. high-performance cam
Note: 208/220° @ .050”

 

[DeuceCoupe]

Yikes, yet ANOTHER set of .050 durations for that same Magnum "268-284" cam.
So now I've seen
228-241 (seems big, but no bigger than the Olds W30 or Ford 429cj)
213-225 (about like the Pontiac RA1-RA3)
208-221 (that's kinda small for a 1.50 Rocker arm)
The plot thickens.

If the six pack was a different cam maybe it was the bigger one, the 228-241? It's been so long I don't remember how the originals idled.

Sometimes I try to guess at cams by how the road test cars ran back then, and get my "Gonkulator" to match them.
Trouble is, the smaller 213-225 loses about 10hp up high but gains about 10ftlb down low compared to the bigger 228-241 duration.
When running a car thru mufflers and with crappy 1960s rubber, its pretty much a wash - the et/mph don't change enough to notice.
So that doesn't help sort things out.
Any other help appreciated, seems for such a common engine 383mag, 440mag, 440sixpack, these numbers would not be so hard to sort out (for me at least)

 

[Big John]

The 69 440 six barrel (I use Plymouth terms because this is a Plymouth site) was the same lift/duration/etc as the 4bbl cam. The difference was the cam was ground with a slight less taper so the lifters didn't wear as fast with the higher spring rates.

None of the current aftermarket supplier specs are going to be a good base for figuring out what cam specs were 50 years ago. They want to stock as few grinds as needed to cover as many engines as they may sell cams for.

Droptop's specs are the factory deal.

 

[rockdog2112]

383-4 hp and 440-4 hp used the same cam. 440-6 had it's own cam. For '69 any way. Not sure about other years.

268/284 Duration, 0.450"/0.458" lift, 46 degrees overlap (115 LSA), installed at 113 Intake CL. is the 383 - 440 hp cam specs.

Does anyone still grind these same specs?

 

[CompSyn]

The 69 440 six barrel (I use Plymouth terms because this is a Plymouth site) was the same lift/duration/etc as the 4bbl cam. The difference was the cam was ground with a slight less taper so the lifters didn't wear as fast with the higher spring rates.

Good visual:

 

[CompSyn]

Mr.6Pack

For anyone wanting a very good stock type cam, likely the best, I strongly suggest calling Bob Karakashian, and forget the aftermarket.



Both of Bob's cams in action here ->

[video=youtube_share;OFaPlDt2jt4]http://youtu.be/OFaPlDt2jt4[/video]

Love that sound!

 

[69hemibeep]

Its to bad they didn't use a 69 hemi, they pulled more rpm utilizing the heads with the solid lifter cam.

 

[mcmopar]

Bob is a magician with his 6 pack. I talked with him about installing one of his cams in my 383. He said install it with 2 degrees advance and it would run great. I am tempted to give it a try one day...