Tumble Port vs. Split Port

[Pitch Black]

Alright, my understanding is that the 96-98 4V heads are tumble port and the 99+ 4V heads are split port. First of all, is this correct?

Second, whats the pro's and con's of each?

 

[Darkhorse845]

Yes

 

[Pitch Black]

Nobody??

 

[5.0's 4 ever]

Actually it is wrong, 93-98 4v heads are split port while 99+ 4v heads are known as tumble port.
The split port heads are in no reason "bad" they make plenty of power but tumble port heads will produce superior torque and midrange power compared to the split ports. Then you have the 03/04 tumble port heads that are the best all around 4v head. Intake port that is slightly larger than the FR500 head and an even bigger exhaust port. Add in the fact that they can be picked up for very cheap, they just can't be beat and thats why I run them.

 

[Pitch Black]

Damn, I thought it might have been backwards. I know 96-98 4V heads have 2 intake ports while the 99+ heads have 1 port....hence "split" port. Anyway, I heard that split port is better suited for forced induction?

 

[Pitch Black]

BTW, have you dynoed your 96 with the 03 heads? Where did you get the heads?

 

[5.0's 4 ever]

I bought my heads from karkraft, they were complete takeoffs with cams for $450. I had the car dynoed about 2k miles after the motor was built, the compression was brought down near 9:1 to run twin turbos. It made 271rwhp and 288rwtq corrected on a SuperFlow dyno. My numbers are not impressive due to dropping the compression and not running on a dyno jet. For a good comparision of what kind of power you would be making on a 96-98 with stock compression and 03-04 heads just look at the numbers the 03-04 Mach 1 guys are putting out.

 

[AzSnake]

Actually it is wrong, 93-98 4v heads are split port while 99+ 4v heads are known as tumble port.
The split port heads are in no reason "bad" they make plenty of power but tumble port heads will produce superior torque and midrange power compared to the split ports. Then you have the 03/04 tumble port heads that are the best all around 4v head. Intake port that is slightly larger than the FR500 head and an even bigger exhaust port. Add in the fact that they can be picked up for very cheap, they just can't be beat and thats why I run them.

I have been thinking of this mod for some time n my car but I have some questions.
What was involved with your fuel system? Did you have to turn it to a return-less system? Did you need a new tank and did you need a 99+ computer?
I want to get all the info together before I invest in the heads. Also correct me if I’m wrong but don’t all these heads use the same intake and exhaust valve? The FR500 heads note that you can use the stock valves from 96-04 Cobra motors on them. Did you install or have it done? I don't want to get into installing them so I'm looking for an avarage price.

 

[AzSnake]

I bought my heads from karkraft, they were complete takeoffs with cams for $450. I had the car dynoed about 2k miles after the motor was built, the compression was brought down near 9:1 to run twin turbos. It made 271rwhp and 288rwtq corrected on a SuperFlow dyno. My numbers are not impressive due to dropping the compression and not running on a dyno jet. For a good comparision of what kind of power you would be making on a 96-98 with stock compression and 03-04 heads just look at the numbers the 03-04 Mach 1 guys are putting out.

Aren't the Machs running higher C/R than the 96-01 CObras?

 

[Pitch Black]

Aren't the Machs running higher C/R than the 96-01 CObras?

yes

 

[bigpapa]

I bought my heads from karkraft, they were complete takeoffs with cams for $450. I had the car dynoed about 2k miles after the motor was built, the compression was brought down near 9:1 to run twin turbos. It made 271rwhp and 288rwtq corrected on a SuperFlow dyno. My numbers are not impressive due to dropping the compression and not running on a dyno jet. For a good comparision of what kind of power you would be making on a 96-98 with stock compression and 03-04 heads just look at the numbers the 03-04 Mach 1 guys are putting out.

The guy are karkraft told me he doesn't sell 03-04 heads. That he gets a million calls and that he just doen't get them. He does sell however the 99-01 heads.


http://www.karkraft.com/modular_parts.htm

 

[5.0's 4 ever]

The guy are karkraft told me he doesn't sell 03-04 heads. That he gets a million calls and that he just doen't get them. He does sell however the 99-01 heads.


http://www.karkraft.com/modular_parts.htm

I don't know why they don't have them anymore. I bought a set back in january of 04 from them along with a complete 99 cobra intake manifold, it seems like all their prices have gone up since then.

 

[5.0's 4 ever]

I have been thinking of this mod for some time n my car but I have some questions.
What was involved with your fuel system? Did you have to turn it to a return-less system? Did you need a new tank and did you need a 99+ computer?
I want to get all the info together before I invest in the heads. Also correct me if I’m wrong but don’t all these heads use the same intake and exhaust valve? The FR500 heads note that you can use the stock valves from 96-04 Cobra motors on them. Did you install or have it done? I don't want to get into installing them so I'm looking for an avarage price.

For the fuel system I used my original 96 rails, had the brackets cut off and welded on so they would bolt up to a 99+ manifold.
Other stuff you will need: a 99+ intake manifold and tube, 99+ throttle body and cruise control cables, exhaust manifolds, a chip burned to turn off the IMRCs, modify the vacuum lines, lenghten some of engine wiring harness wires, a set of 99+ valve covers(you can run 96-98s but the fittment around the throttle body is very snug), a 99+ coolant crossover tube with an extra bung welded into to run the ECT and temp sender, and you may possibly need a new midpipe, my 96-98 bbk o/r H did not fit the 99+ exhaust manifolds so I got a VRS o/r X.

They all have the same valve diameters, 37mm int/30mm exh, but I do not know they are the same exact part number.

Al Papitto of Boss330 Racing built my shortblock, Lamotta performance assembled my longblock did the necessary welding work and later on tuned my car with the help of superchips.

 

[5.0's 4 ever]

Aren't the Machs running higher C/R than the 96-01 CObras?

They are running a higher ratio, but not by a lot. The mach1 has 10.1:1 while the cobra has 9.9:1

 

[AzSnake]

For the fuel system I used my original 96 rails, had the brackets cut off and welded on so they would bolt up to a 99+ manifold.
Other stuff you will need: a 99+ intake manifold and tube, 99+ throttle body and cruise control cables, exhaust manifolds, a chip burned to turn off the IMRCs, modify the vacuum lines, lenghten some of engine wiring harness wires, a set of 99+ valve covers(you can run 96-98s but the fittment around the throttle body is very snug), a 99+ coolant crossover tube with an extra bung welded into to run the ECT and temp sender, and you may possibly need a new midpipe, my 96-98 bbk o/r H did not fit the 99+ exhaust manifolds so I got a VRS o/r X.

They all have the same valve diameters, 37mm int/30mm exh, but I do not know they are the same exact part number.

Al Papitto of Boss330 Racing built my shortblock, Lamotta performance assembled my longblock did the necessary welding work and later on tuned my car with the help of superchips.

Hmmm, I may be PMing you whent he time comes for thsi project.

 

[5.0's 4 ever]

No problem