Original factory cam duration, 383/440mag, was it 228-241 or 213-225 or 208-221? Ugh!

[DeuceCoupe]

Hi there, I am looking for the .050 durations on the original factory cam for the
383magnum
440magnum
440sixpack
I've heard this is all the same cam (the 268-284 advertised) and then I've heard the sixpack is different.
I've also seen .050 durations of
228-241
213-225
208-221
For this same cam.
That is a lot of spread!

I know there are various "OEM repro" cams out there but in my experience these are not always what the factory put in back then.
And of course, Mopar had a habit of putting smaller cams in the slushbox cars - I've never seen this claimed for the 383/440 but with so many durations out there who knows?

I also posted this question over on 69roadrunner too FYI:
http://www.69roadrunner.net/mopar/s...am-is-it-228-241-duration-or-213-225-duration

Your insight much appreciated!

 

[Banzaiii67]

440: Stock Hydraulic P4452783
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” (R. Karkashian)
Note: as installed on 113° centerline per Chrysler

 

[Tempest 455]

Same specs above I posted on other site for seat timing.

 

[Mebsuta]

I have also wondered about this.

The 208-221 @ .050 seems to come from multiplying 268/284 by .777.

The 213-225 or 214-224 is what I find in most catalogs for Elgin, Melling, Clevite, Federal Mogul, Speed Pro, etc.

I found an old post on another site where somebody who is a member here actually measured it, and it was 213-225. I think it was Lew*.

This is for the 383-440 HP cam.

The 440+6 is something I don't know about. Have read that it was the same, except for low taper for heavy spring pressure and high rpm operation.

- - - Updated - - -

A long time ago I put P4452783 in 383 RR, and as far as I'm concerned it behaves and sounds just like the vintage original that it replaced. Maybe I shouldn't have tossed the original decades ago. We could have measured it.

- - - Updated - - -

As far as seat-to-seat timing, it's hard to tell what's going on because everyone seems to measure that differently. To my knowledge Comp uses .006 lifter rise, Crane uses .004, some use .006 valve lift, Isky uses a different point on opening and closing.

That's what's frustrating about Desktop Dyno. It wants seat-to-seat figures, but everyone's are figured differently unless you are comparing cams from the same family from the same manufacturer.

 

[lewtot184]

the 213-225 is accurate. they're ground on 115lsa with 2 degrees of advance. the 268-284 numbers don't include the long closing ramps.

 

[Tempest 455]

As far as seat-to-seat timing, it's hard to tell what's going on because everyone seems to measure that differently. To my knowledge Comp uses .006 lifter rise, Crane uses .004, some use .006 valve lift, Isky uses a different point on opening and closing.

That's what's frustrating about Desktop Dyno. It wants seat-to-seat figures, but everyone's are figured differently unless you are comparing cams from the same family from the same manufacturer.

That's why you measure @ .050" with a degree wheel and dial indicator. Then you get apples to apples.

 

[lewtot184]

i measure seat timing using the cam grinders lobe lift number, .050", .200", and .300". to know what the real profile is all the numbers have to be put together. asymetrical lobes are the wild card.