360 Magnum

[duane_koda]

i've got a '94 360 Magnum in my Dodge Dakota. Later on down the line I'd like to get some big hp/tq. numbers. I would like to get around 400hp preferably under 6000rpms. I want it naturally aspirated. I need to make a list of what I need. Injector size? How big of a cam can I get b/c I heard that engines that run with computers are sensitive to that (maybe not I don't know). I would like to keep it on pump gas. If I had the stock intake and throttle body bored out would that be enough, or should I get a new intake? I've got the hp computer. What kind of work needs to be done to the heads? How big should the intake/exhaust valves be? I know it's a lot to ask but if someone could help me out I would really appreciate it. Feel free to add anything I left out because I'm not thinking too clearly with my cold.

[dewme5]

well, I would guess the crate 380 could be some inspiration.

I would really suggest the magnum aluminum heads.

when you said 400 hp. are you talking to the flywheel or to the rear wheels?

[duane_koda]

well I was just looking for flywheel horsepower but if I can get 400 to the pavement that would be awesome. I looked at the specs of the 380 Mag. Just curious what I need to do to get the same potential with fuel injection. Like how much injector and throttle body do I need.

[dewme5]

well.. with fuel injection, you are at much less of a problem by running to large of a throttle body. Being right, is better than being wrong still, but you can go over size on a throttle body with out the problems that a carb is going to bring up. if you are looking for something to put 400 hp to the ground, naturally aspirated. i would get about 750 cfm. (keep in mind that it is going to have to work with your computer, and that, I don't know anything about.) a cam is something that is going to best be worked out with comp cams, or somebody like that. I would check with hughes engines. they probably have a package available for what you are talking about. With considering the new cam, you are going to need new valve springs. why go thru all the trouble of a cam and springs if your heads aren't good enough. (supposedly, there is a difference between the normal magnum 360 heads, and the crate 380 magnum heads.... I don't know about this for sure, but I did read it a couple times. I can get the numbers off of my heads if you really that curious. since I have the 380/360 crate.) you can get worked magnum heads for not to much money, but the aluminums are going to make you happier in the power department.

injectors... do you have 8 injectors, or just the 4 as in a throttle body setup. the formula is


copied from "Fuel Injection Installation, Performance Tuning, Modificatins" by Jeff hartman

Flow Rate = (hp*BSFC) / (# of injectors*max cycle)

flow rate--- is in pounds per hour of gasoline
hp -----is projected engine horsepower (this may increase with port injection); for the formula to be useful, this must be realistic
BSFC--- is b rake specific fuel consumption in pounds per horsepower-hour, generally 0.4 to 0.6lb (possibly higher) at full throttle. Start with 0.45 for naturally aspirated engines, 0.55lb for turbo-supercharged engines.
# of Injectors--- is the number of injectors you're using
Maxcycle--- is the maximum duty cycle of the injector. According to Lucas, this is 0.8 (80 percent) for a typical OEM ECU; aboce this, the injector will begin to over heat, which can cause it to lose consistency-- or even fail completely!!

example. flow rate =(240*.65)/(8cyl * 0.8) flow rate = 24.37lb per hour injectors.