What are the differences in the 4.6 engines( GT, mach, cobra) That make them respond differently to mods.

 

2v GT vs 4v mach 1 and cobra.

 

What does 2v and 4v mean. Are the older cobras 4v too

 

2v. each head has an exhaust and intake valve, also only 1 cam per head..total of 2.
4v. each head has 2 exhaust and 2 intake valves, also has 2 cams per head..total of 4.

 

it means 2 or 4 valves per cyl.. The 4v has 2 cams per head to open close both sets of valves (DOHC) where the 2v has only one cam per head to open and close the valves (SOHC). Different cars/years respond different to the same mods.. for instance your going to get more of a gain on an older 2v by switching out the head then on an older 4v (like mine) because the 4v had much less restrictive heads to begin with... or a pully swap on a new cobra can net a huge gain because of the supercharger, where on the 2v or older non FI 4v's all you can do is swap in underdrive pulleys for a small gain... it has to do with what the vehicle came from the factory with vs the effect the aftermarket part will give it.

 

The main reason that the 3 and 4 valve cars respond better to mods is the added intake valves (valve). The 2v 4.6 head does not really flow all that well. When Ford designed the modular engine certain compromises had to be made and due to packaging problems (getting it to fit in certain cars) . This could have been solved by making the block/heads/intake sit at a different angle but that would have made it harder to fit inthe cars again. Enter the 3 and 4 valve engines, adding more valves solves the poor intake runner problem in the heads allowing more air flow. The more air in and the more air out the more power potential the engine has.

 

Which years of the cobra were 4V

 

96-04

 

I was lookin on KBB and it said that the 03-04 cobras were DOHC 2-valve. It didnt seem right, but then neither does a SOHC 3-valve (for similar reasons) I guess if they do one, why not the other.... but anyway, is that info correct?

 

the 05-06 is a SOHC 3v i dont know if thats what you were looking at.