navigator heads with 03 cobra cams

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looking for 500.00

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450.00

[NXcoupe]

What's the difference between these and a set of 99/01 cobra heads?

[orangeconv]

in short they flow better and the cams are totally different the cams are actually 03/98 cams. i can find the number if you want them

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---------2003--------2001-------Difference
Lift----Exh---Int----Exh----Int---Exh---Int
0.050--35----46-----28----35---+7----+11
0.100--74----95-----68----87---+6----+8
0.150--105---128----99---118---+6---+10
0.200 --126---161---121---153---+5---+8
0.250--146---182---136---184---+10---(-2)
0.300--159---226---145---204---+14---+22
0.350--165---245---151---218---+14---+27
0.400--171---259---153---223---+18---+36
0.450--173---262---156---228---+17---+34
0.500--175---266---158---231---+17---+35
0.550--176---268---159---231---+17---+37
here are 03 vs 01 head flow numbers

[orangeconv]

Navigator: (98+ Lincoln Navigator)
These 5.4L DOHC heads feature essentially the same intake port design as C heads, however they have a much larger intake port volume than 4.6L castings. Despite the fact these heads feature a relatively small exhaust port, the extra intake port volume could be very beneficial in helping fill a motor of greater displacement—think 5.4L. Expect slightly better midrange torque, and sub 8000rpm horsepower production than even C heads, however the larger intake port size leaves a slim selection of intakes to choose from when utilized on a 4.6L block. Forced induction fans take note, Navigator exhaust ports feature a thicker exhaust divider (while keeping the same overall exhaust port size as B,C, and FR500 heads) that allows coolant to circulate through this vital area. Conversely however, the larger divider can also hurt flow by utilizing additional space in the port.
The real downside to Navigator heads, when used on a 4.6L based motor, is the severe limitation they impose on intake selection. The physically larger 5.4L heads don’t leave a lot of room (when installed on a 4.6L block) between them for an intake plenum to sit—though they do bolt right up. Remember that since Navigator intake ports are essentially clones of those of C heads (just on a larger scale), they too suffer from the same intake port flaws that plague the earlier tumble port design--no short turn or floor in the throat of the intake port.
The Bottom Line: The extra port volume the Navi’s possess could be very beneficial in filling a motor with greater than 281 cubic inches of displacement, or in high rpm N/A street/strip or boosted combinations. Fans of boost should remember the cooled exhaust port divider. Lack of intake availability is the real downfall of this otherwise wonderful casting.


flow numbers are in the sean hylan book to compare i dont have it on my computer

[NXcoupe]

Ok, so it requires a custom intake then? Sorry for the questions, this is something I've been curious about for a while.

[orangeconv]

I don't think it does

[NXcoupe]

Navigator: (98+ Lincoln Navigator)
These 5.4L DOHC heads feature essentially the same intake port design as C heads, however they have a much larger intake port volume than 4.6L castings. Despite the fact these heads feature a relatively small exhaust port, the extra intake port volume could be very beneficial in helping fill a motor of greater displacement—think 5.4L. Expect slightly better midrange torque, and sub 8000rpm horsepower production than even C heads, however the larger intake port size leaves a slim selection of intakes to choose from when utilized on a 4.6L block. Forced induction fans take note, Navigator exhaust ports feature a thicker exhaust divider (while keeping the same overall exhaust port size as B,C, and FR500 heads) that allows coolant to circulate through this vital area. Conversely however, the larger divider can also hurt flow by utilizing additional space in the port.
The real downside to Navigator heads, when used on a 4.6L based motor, is the severe limitation they impose on intake selection. The physically larger 5.4L heads don’t leave a lot of room (when installed on a 4.6L block) between them for an intake plenum to sit—though they do bolt right up. Remember that since Navigator intake ports are essentially clones of those of C heads (just on a larger scale), they too suffer from the same intake port flaws that plague the earlier tumble port design--no short turn or floor in the throat of the intake port.
The Bottom Line: The extra port volume the Navi’s possess could be very beneficial in filling a motor with greater than 281 cubic inches of displacement, or in high rpm N/A street/strip or boosted combinations. Fans of boost should remember the cooled exhaust port divider. Lack of intake availability is the real downfall of this otherwise wonderful casting.


flow numbers are in the sean hylan book to compare i dont have it on my computer

The highlighted part is what prompted that question.

[Rich]

Michael,

This would solve the intake problem and far out perform any factory intake.

http://www.sullivanperformance.com/yvs450/products/intakemanifold/intake4.6.htm

[NXcoupe]

Michael,

This would solve the intake problem and far out perform any factory intake.

http://www.sullivanperformance.com/yvs450/products/intakemanifold/intake4.6.htm

You offerin to buy that for me? Or just spendin my money? lol

[orangeconv]

yea i checked it out. you would need to do some work on the intake to make it work on a 4.6. sullys the way to go....

[red srides]

they make spacers so u can bolt a 302 intake on the 4.6 4v they r nice ebay