Determining Mopar Performance camshaft • The Dodge Challenger Message Board

by **Robbert D 70`Chally (383m** » 25 Mar 2002 18:10

I want to know if my stall converter fits my camshaft, so I want to know exactly what camshaft I have mounted. It is said to be probably a Mopar Performance 268/284 "purple cam". My tranny is disassembled since thursday, so I could remove the freeze plug (one is never wet...) behind the camshaft. It shows three holes in a row, and the #891597.
Can't find that in my books, nor on the web (no relevant links... ok its a "twin prime", duh)
Mopar.com techline: 248-969-1690 is out of order.
Who can help me out?

by **Dave-R (Roppa440)** » 25 Mar 2002 21:07

An MP cam would have a seven digit part number starting 41, 42 or maybe 45. Also the Chrysler camshafts always used to have the same duration and lift on both the intake and exhaust.

by **Robbert D 70`Chally (383m** » 26 Mar 2002 1:14

Hm, I don't like that. This raises a couple of questions.
1. Now my cam does not have one of the #s you are referring to on its end, is it out of the question it is a MP camshaft?
Couldn't there be another place to read this # on an MP cam?
2. No matter what make this cam is, is there an easy way to find out both lift and duration of a camshaft without disassembling? (I would say lift yes, duration no). Ok forget easy.

I think I found out not all Chrysler cams are symetrical.
I. Check the book “Mopar performance” (Larry Atherton, S-A Desing Books) page 101 2nd paragraph:
“Unfortunately, most of these early profiles are no longer available from Chrysler, but one that is, and can be purchased through any dealer, is the 440 4-barrel cam (PN 3512907). This street beauty wiht 268° intake and 289° exhaust duration and .450-inch lift brings the “ponycar days” back to life.”
II. On B/RB mopar cams we see a lot of symetrical ones, but not all. The one in top is the P4452783 268/284, and that is supposedly my camshaft, here described as “Resto, 383 / 440 magnum, super commando, road runner”
Please correct me if I misunderstood you. Quite a puzzle.

by **Dave-R (Roppa440)** » 26 Mar 2002 8:43

Sorry. I was refering to the aftermarket cams MP used to produce. I don't take much interest in them these days as I did not think they were very good. maybe they are better these days but I doubt it. Very little lift for the amount of duration.

If you get a cam timing degree wheel/dial indicator and a solid lifter it is possible to find the spec of the cam.

The part number would be on one end or the other of the cam I would have thought. The makers name at least would be on the front end I think. Maybe you are just looking at the wrong end?

by **Dave-R (Roppa440)** » 26 Mar 2002 20:44

I just had a quick look. The old factory stock cams have a dual profile and the 268/284 is the bog standard 383/440 4bbl cam. It had 0.450" lift on the intake and 0.458" on the exhaust. Not considered very high performance.

The Mopar Performance aftermarket cams in the rather old books I have all have the same lift and duration on both lobes.

A good hydraulic cam will have a tenth of an inch more lift for almost the same duration.

by **vooodooou** » 05 May 2008 19:43

can you say 1.6 rocker arms

by **dave-r** » 05 May 2008 20:34

Yes. And the MP cams will still be crap. :p:

Can you say 1.6 ratio rockers on a decent profile?

by **Eddie** » 06 May 2008 13:09

The MoPar Perf cams will allow lifters as small as .842 to be used even though the MoPar lifter is a .904 diameter. This means all mopar cams are ground on blanks that were developed for Chevys! It's much cheaper for the cam grinder!!!!If you want a true MoPar .904 cam just ask the cam supplier what the minimum allowable lifter diameter is to be used with this cam. If the answer is lower than .904 keep looking. I like Comp Cams Fast Rate of Lift cams and Howards Solid Race lifters with EDM oiling,(.904). Bullet cams is a good one as is UltraDyne. I wont use MoPar Perf. anymore, to outdated!! :mrgreen:

by **dave-r** » 06 May 2008 13:16

Not just outdated.
As if a 40 year old design was not bad enough there have also been quality issues in recent years. I know of a few people that have wiped cam lobes despite careful start up and running in.

These cams can make good power. Just not as much as other cams with the same duration.

by **Eddie** » 06 May 2008 13:20

Heard that too Dave! I wonder if Danny's cam was a M.P.? I think he said it was. :wink:

I'm not taking any chances with mine during breakin. Outer springs, oil through lifters, EOS and Valvoline Race oil@30Wt. 2000-2500 RPM's :thumbsup: