Looking at Ford Racing DOHC 4.6L Heads...

[MR.ADAMS]

-Ford Racing 4.6L Performance Cylinder Heads

What's the word on these? Good, bad, neutral?

I'm looking at an unused set of these heads but I'm wondering if there will be any noteworthy performance gains while using the stock valvetrain, cams, etc. The only parts that would change would be those needed to do the swap such as the C-head intake, exhaust manifolds.

I have no experience with these heads and any input would be much appreciated as this will help me decide on purchasing or not.

Thanks!

 

[OCSnk]

Some info I have on file:


’03/04 DOHC head dimensions: Combustion Chamber: 52cc, Intake Port Vol.: 177cc, Intake Port Entrance: 1.960”x1.350”, Valves: 37mm Int., 30mm Exh.

FR500 head dimensions: Combustion Chamber: 53cc, Intake Port Vol.: 160cc, Intake Port Entrance: 1.960”x1.350”, Valves: 37mm Int., 30mm Exh.

The FR500s only real fault is that the newer ’03 DOHC and the 04 heads provide near identical performance capability (much better on the exhaust side) paired with a cost differential that is approximately two-thirds less than the FRPP castings.


‘03/04 DOHC head: (‘03+ Aviator, Marauder, Cobra, Mach 1, Australian Boss 260/290)
Featuring a nearly identical (though 17cc larger in volume due to the fact that they are also used on the much larger Australian Boss 260/290 5.4L DOHCs) intake port to the FR500 head, but combining it with a newly designed, larger and more rectangular exhaust port, these may be the best all around DOHC Ford heads ever manufactured.

The improvements made to the intake port shape over previous years include a raised port roof and the introduction of a short radius turn in the throat of the intake port that helps assure the incoming air charge finds the combustion chamber. For those with a forced induction street/strip motor, these are without question the best heads available, and as with the FR500s, they should produce great power up to and beyond 8000rpm regardless of application. ’03 DOHC heads also feature higher quality head castings from the supplier, which is at least partially responsible for the modest increase in flow vs. earlier castings--chalk that up to Ford’s revised quality control standards.

Early runs of the ’03 DOHC head fell victim to the same #6,7,8 cylinder coolant flow problems as earlier tumble port castings. In mid ’03 Ford made a running revision to the ’03 DOHC heads that allowed for more coolant to circulate through the affected areas. A blue mark on the driver’s side head indicates an updated casting, and there are no additional revisions to the ’04 version of this design.

The Bottom Line: On all accounts these are the best modular four valve heads currently available. They combine the exceptional flow of a slightly larger FR500 intake port with a gigantic new rectangular exhaust port.

The Bottom Line: On all accounts the late 03 and the 04 are the best modular four valve heads currently available. They combine the exceptional flow of a slightly larger FR500 intake port with a gigantic new rectangular exhaust port.

 

[MR.ADAMS]

Thank you very much, Sir! That was a good technical read, much more helpful than I could have expected.

:beer:

 

[na svt]

-Ford Racing 4.6L Performance Cylinder Heads

What's the word on these? Good, bad, neutral?

That is a good read but it doesn't answer the question. When compared to your 96-98 heads both the 03/04s and the FRs are much better. When combined with your 96-98 cams they both will provide more torque and hp from idle to redline. However, you will also need and intake manifold, throttle body, throttle and cruise cables, EGR tube. The fuel rails will also have to be modified to fit the new intake. The stock exh manifolds will work with any of the 4v heads.

 

[MR.ADAMS]

Thanks NA. I knew the intake manifold, throttle body, and throttle cable would need to be swapped. I didn't know about the fuel rails though. My EGR is gone and my Cruise has never worked, and for some reason I thought the exhaust manifolds were different, but I guess I was just thinking of the SAI bungs and things.