428 PI Cam

KevinM · #1 (**permalink**) 02-19-2008, 09:42 AM

I have read in a few places that Shelby may have installed a different cam in the 428PI engines used in the Cobras.

Can anyone confirm this? And if true, what were the specs on the Shelby cam?

Thanks,

Kevin

patrickt · #2 (**permalink**) 02-19-2008, 11:35 AM

The 428 "P" engine had two camshafts listed as "Service Parts," which meant the dealer would put these high performance parts in for you, or your engine might be pulled off the line to have it installed at the factory. EDIT -- C3AZ-AA appears to be the solid lifter cam that was put in the PI, see my detailed answer a couple of messages below.

KevinM · #3 (**permalink**) 02-19-2008, 12:03 PM

Patrickt,

Thanks. Do you know what the specs were for the factory 428PI cam?

I have this info on the C60Z cam: "The cam originally used in all 428 CJ and SCJ engines was serviced using Ford part number C6OZ-6250-B. This is a hydraulic, flat-tappet cam with a 15-tooth distributer gear that was also used in 1966-1968 390 GT engines."

Was the factory 428PI cam the same cam they used in the 66-68 390 GT?

Kevin

patrickt · #4 (**permalink**) 02-19-2008, 12:52 PM

Quote:

Originally Posted by KevinM

Thanks. Do you know what the specs were for the factory 428PI cam?

I show the C60Z-B as having Intake 38/86 degrees with .481 lift and the Exhaust as 96/48 degrees with .487 lift. If installed straight up, it would look something like this:

Quote:

Originally Posted by KevinM

Was the factory 428PI cam the same cam they used in the 66-68 390 GT?

That cam was used in the '68 390 engine that put out 325 horsepower, but I also show a C6AZ-A in the '66 390 engine that put out 335 horsepower. There were also several weaker cams as well.

patrickt · #5 (**permalink**) 02-21-2008, 05:20 PM

According to the owner's web site, CSX3282's 428PI had the solid lifter AA cam, which has the same specs as the D cam (the 427 sideoiler requires grooved journals). Specs are identical. Here's the page in which he talks about his AA cam. 427 Cobra - CSX3282
The specs of the C3AZ-AA cam are:

Intake Open: 40.5
Intake Close: 85.5
Exhaust Open: 88.5
Exhaust Close: 37.5

Lift .500/.500
Duration: 306/306

KevinM · #6 (**permalink**) 02-21-2008, 05:44 PM

patrickt,

Thanks, that is pretty definitive.

Kevin