I have read here that the .509,and .590 are old Racer Brown grinds.(some say the .590 was an old Isky hardface?)The 284/.484 an R.B. as well. Looking at the .557 spec I'm guessing a Comp grind?(Comp seems fond of the 110* LSA) The .528, don't have a clue.


I can never get enough of "cam talk" So what is the origin of these "old dinosaurs".


And in particular what would be the "better cam" to replace the old .557?

I believe Racer Brown did the original ones back in the 70's. I use the .557 cam in my mild 440 and I love that cam. Ron

I know where the 590 came from..........Heaven.

Whom ever returned the lowest bid on the work.
I know that the quality of these cams in the last 10 years has really been poor. Hit or miss on quality...
I wiped a few lobes..about 3-4 on a 590 MP cam back in 04 on my brand new 493 engine. I did everything correctly..it still ate lobes.

Zippy said they are currently ground by an OEM in Jackson MI.



But that is not really my question.



I was more interested in the origin of the grinds i.e. Racer Brown, Comp, Isky, Crane.


Or are the Chrysler Engineers the ones who came up with the profiles?

Chevy

Ever heard of 3/4 grind? Thats where it started.

IIRC the original 484 and 509 Purple shafts were the Racer Brown SH-25 and SH-44 grinds from the 60's, when Direct Connection came about inthe early 70's Ma had them repackages as their own house brands.

The old engine manual bears this out as you can see a number of Racer Brown cams were used for bracket car development testing and are listed on their cam lists....and going way back to 73 or 74 the original DC parts catalogs listed a few Racer Brown cams along with the Purples.

Not Chevy.Their performance grinds back in the day were mostly road race grinds.The 'mopar lobes' was really a clever marketing scheme.It is also true there are advantages to a larger lifter.GK had fast lobes in the late 60's esp for Chevies.One problem was the rest of the valve train was not up to what was needed for the most part.Another was the lack of cyl heads that we have today.Chrysler engineers did use some Isky and Racer Brown grinds as a basis for the MP cams.Camcraft and others were also involved back in the day.