428CJ Stock Class Valve Lift .527 ?

[SSDiv6]

Originally Posted by DeuceCoupe

Thanks Paul.
So then
1. You're saying the .527 lift is a recent change, like in the last 20 years?
2. What cam IS that? It must refer to an OEM grind, right?
3. The only OEM cam I know of even close to .527 lift is the SOLID 306-306 duration cam used in
352HP 1960
390HP 1961-62
406 1962-63
427 1963-67
428PI 1966 only
That had .298 lobe lift which is .524 gross at 1.76 rocker.
Is THAT the .527 lift "OEM FoMoCo" cam?
Or some other cam? Solid or Hyd? Which do you run?

Can of worms indeed.

Interesting information on this link:

https://www.428cobrajet.org/id-cam

...just waiting for the letter that says the C8AX-6250-D camshaft, with 0.600"/0.0600" lift and 330 duration (273°/273° @ 0.050"), 107 LSA is also legal...

[DeuceCoupe]

Originally Posted by SSDiv6

Interesting information on this link:

https://www.428cobrajet.org/id-cam

...just waiting for the letter that says the C8AX-6250-D camshaft, with 0.600"/0.0600" lift and 330 duration (273°/273° @ 0.050"), 107 LSA is also legal...

I'll have to hunt for this text in some old Ford documents:
"Ford described this cam as ".515 lift-steel-use on hydraulic lifter engines".

I dont recall seeing the .515 before but it's in the link you gave.

The most legit info from the era I have is is in March 1968 issue of ShopTips (cant attach a PDF here) which is either on 428cobrajet.org or Mustangtek. It refers to the C8AX-C cam as "production" (LOL) with
.500 at 1.73 rocker lift or
509 at 1.76 rocker lift
The same issue lists the 1968 NHRA classes, and running the 428CJ in either C/S=9.00 class or SS/E=8.70 class, which implies the 360hp factoring was already up to date.

That much I think we all get:
The C8AX-C cam is not known to ever have left the assembly line (at least not under the hood) but it was legal for NHRA Stock at
.509 .509 lift

I'm still thinking that .527 lift as now listed in the NHRA blueprints is some kind of a garbled number, either from mixing up .289 lobe lift (C8AX-C hydraulic) with .298 lobe lift (427 SOLID cam).
.298 lobe lift gives
.515 valve at 1.73 rocker (same as the strange text on 428cobrajet.org) or
.524 valve at 1.76 rocker.

If there's actually a 428CJ-Legal cam with that lift, that's what I was hunting for.

EDIT:
I found the strange .515 lift for C8AX-6250-C.
Here is the page from 1965-72 MPC Master Parts Catalog showing it.
I think the .515 number here is an error, but the point is, it's THERE, so could be easy for it to propagate into a "Blueprint". Still, .515 (assuming 1.73 rockers) is only .524 with 1.76 rockers, not .527. But at least we know the source of the .515 number.

[SSDiv6]

Originally Posted by DeuceCoupe

EDIT:
I found the strange .515 lift for C8AX-6250-C.
Here is the page from 1965-72 MPC Master Parts Catalog showing it.
I think the .515 number here is an error, but the point is, it's THERE, so could be easy for it to propagate into a "Blueprint". Still, .515 (assuming 1.73 rockers) is only .524 with 1.76 rockers, not .527. But at least we know the source of the .515 number.

Here is an interesting discussion regarding the C8AX-6250-D camshaft from the guy that designed it.

https://www.fordfe.com/c8ax-6250-d-r...s-t164022.html