428CJ Stock Class Valve Lift .527 ?

[SSDiv6]

Originally Posted by DeuceCoupe

We cant figure this out on Fordfe.com

NHRA Blueprint .DOC files for 1968-69-70 say the 428CJ valve lift is
.481 .490 ok
But a footnote for each year shows an OPTIONAL 428CJ cam with lift
.527 .527

I've read that Ford said the C8AX-C hydraulic cam was "optional", with lift of
.500 .500 1.73 rockers or
.509 .509 1.76 adjustable rockers
AFAIK no 428CJ ever left the factory with that cam but several sources say it was NHRA Stock legal even back to 1968.

But a cam with
.527 .527 lift in STOCK class 428CJ
Is this a typo (for all 3 years) or what?
What are stock class 428CJ's running today as max lift? .509 or .527?
thanks in advance

That camshaft is only applicable to the 1967 through 1969 Shelby Mustangs, not the regular Mustangs.

In lieu of looking at the Ford Engine Blueprint specs, look at the bottom of the list and look at the Shelby specs.

http://www.nhraracer.com/content/gen...634&zoneid=132

[Paul Wong]

Its applicable to all 428 cobra jet engines. I had built a brand new 428 for my Torino over 20 years ago and this rule changed allowing the .527 camshaft. The addition of parts at that time in A-D cars was out of control. It was by no means brand specific. There have been many battles to take parts back but have only been successful taking parts from mopars.

[DeuceCoupe]

Originally Posted by Paul Wong

Its applicable to all 428 cobra jet engines. I had built a brand new 428 for my Torino over 20 years ago and this rule changed allowing the .527 camshaft. The addition of parts at that time in A-D cars was out of control. It was by no means brand specific. There have been many battles to take parts back but have only been successful taking parts from mopars.

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.

[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

[Ralph A Powell]

From what I experienced is that the 62 406 never used the 306 deg cam in production. My 62 496 was a late June production car and it had the 276 degree cam. I had a insider at Ford get me a production 306 but that was not till late July of 62. He did get me a SK version in late June!

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.

[DeuceCoupe]

Originally Posted by Ralph A Powell

From what I experienced is that the 62 406 never used the 306 deg cam in production. My 62 496 was a late June production car and it had the 276 degree cam. I had a insider at Ford get me a production 306 but that was not till late July of 62. He did get me a SK version in late June!

Ralph, do you recall what the difference was between the 276* and 306* cams (if any)?

I've mostly concluded they were the same grind, just that the "advertised" was measured differently, like 276* at .014" lobe (lash point), or 306* at .005 lobe (more like the way Ford measured their hydraulic cams, and way below lash point for a solid cam).
BUT, this topic goes round-n-round so always looking for more info on that one too.

[Ralph A Powell]

I don’t it’s only been about 58 years. I do remember that in late 63 after the 427 came out I went to the 27 AA cam which was a SK part number at that time. I got it from Sully(Don Sullivan).

[Corbin Dallas]

So- my dad who was a div 3 racer and knew bob glidden , said he thinks that cam was for glidden with help from marty barret along with the canadian" heads. Recalls a yelling match between Mr Glidden and a chevy racer at edgewater untill Marty came over and settled the matter by admitting he had got the cam approved. Even though glidden was racing SS at the time but had customers who ran stock.