Here is what my friend Brian has come up with at Apten Performance, www.apten-us.com We both use the SCT tuning. Most of you know about the rods and pistons in the SOHC and the DOHC motors, they have hypertectic pistons as well as marginal rods the motor is safe up to 450 RWHP, now there are those that believe a roots blower is better than the centrifugal, in 2003 Ford introduced the 03 Cobra, this has the Eaton type blower on it, with a steel crank good forged rods and pistons and good fasteners the car stock makes about 390 RWHP, with a minor changes and a chip it climbs to 450 RWHP. Brian also has been porting the Eaton blower housing and making another 40 or so RWHP, Now another company steps up and makes a bigger roots blower kit for the 03 and with larger injectors and a boost a pump and tune the car makes over 600, we have seen three engines go by by by various companies for what ever reasons, the roots blower spools up quicker but it also generates a lot of heat, one flaw in the 4.6 SOHC or DOHC is poor coolant flow out the back of the drivers side head, we have found that the cylinder temperatures on # 7 and # 8 is over 50 degrees higher than 3 and 4 #7 cylinder is normally the piston that lets go on either of the modular motors this is one of the reasons, I talked to Brian and Jerry W gave us some pointers while in Atlanta, so Brian came up with a kit that allows water to flow out of the back of the drivers head and T in to the passenger side, the passenger side on the cobra motor has a water outlet tube installed in the back of the cylinder head where a freeze plug is normally found on the Marauder engines. This water outlet then goes into the heater core for complete water flow through the engine. Neither of the Marauder heads have a water outlet so we made kit for it, it will insure that the heads maintain even cylinder temperatures. We both sell this kit. I am currently doing a 04 Marauder that I am installing a 03 Cobra motor in the car I am removing the roots with a Centrifugal Vortech JT Trim, some have said why not keep the roots here is why. Brian now has just finished doing the exact same thing on a 03 Cobra. He took off the roots bolted on a ProCharger used 55 pound injectors along with upgraded fuel Pumps the car laid down over 658 RWHP, this is amazing I like centrifugal blowers, so I took Brians coolant mod and applied that to the Marauder engine. This will aso work on the SOHC motor as well.
Here is a picture of the back of the engine and the freeze plugs, as you can see this would be very difficult with the engine in the car. But it could be done. The marauder has no water leaving either head, unlike the Cobra motor that has the one water outlet fiting on the passenger head, so water comes out of the passenger head then flows through the heater core and back out of the heater core into the heater a hose that is conected to a rigid line that runs down the intake valey into the back of the water pump. The marauder has no cross over in the back of the head and no water flow out of either head as shown in the below picture. Now if you look at this picture water flows out of the rigid tube on the right side into the heater core then out and through a heater hise into a rigid line that runs down the head on the passenger side ito a hose that connects to the front crossover pipe.
Now if you look at the pictures below you can clearly see that you will have complete water flow out both heads, this will dramaticly decrease cylinder tempratures wich will decrease spark knock, and may may make possible to run more timing wich will equate to more useable RWHP.
Here is a picture of the back of the engine and the freeze plugs, as you can see this would be very difficult with the engine in the car. But it could be done. The marauder has no water leaving either head, unlike the Cobra motor that has the one water outlet fiting on the passenger head, so water comes out of the passenger head then flows through the heater core and back out of the heater core into the heater a hose that is conected to a rigid line that runs down the intake valey into the back of the water pump. The marauder has no cross over in the back of the head and no water flow out of either head as shown in the below picture. Now if you look at this picture water flows out of the rigid tube on the right side into the heater core then out and through a heater hise into a rigid line that runs down the head on the passenger side ito a hose that connects to the front crossover pipe.
Now if you look at the pictures below you can clearly see that you will have complete water flow out both heads, this will dramaticly decrease cylinder tempratures wich will decrease spark knock, and may may make possible to run more timing wich will equate to more useable RWHP.