What kind of power will going to DOHC offer, or is this more of a mod for preparing to go big dog on the blower and internals? I'm a HP per dollar kind of guy, so estimated HP numbers would get my mind in gear. we talking 10 or 50? Inquiring minds want to know

 

Well there are alot of cobra owners going with a KB or whipple and getting close to or over 600hp without trying to hard. Ported Lightning heads can run $1700-2000 and you can find new DOHC heads for that and used for less. Unported DOHC heads will outflow ported Lightning heads. I think the gains could be real big cause the Ford GT makes 550 underated HP at just 12psi with 2.3 whipple. More boost more power.

 

There's more to it than just flow with the 4V....the valvetrain is better suited to the pressures of high boost. Its just plain easier to control the valves. Case in point, I know that the top 4V mod racers are twisting there engines to 9500+ @ 30+lbs boost and doing it with stock hydraulic adjuster and around .450 lift Then there the central located spark plug and some other little things. Dale

 

hidden costs involved.

you cant just slap on a set of 4 valve heads with out the 5.4 4 v front cover. not sure the price but thats a hidden cost.

cams now your spending twice the amout for aftermarket cams , springs ect. ect. lets face it why do the swap if your not looking for max flow so the head porting is going to cost ya.

not sure if the pulleys and tensioners are in the same location on the 4valve front cover but i'm pretty sure the lightning blower idler bracket wont just bolt up.

headers: the exhaust ports are oval shaped on the 4 valve. as far as i know kooks is about the only company that has or will make a 4 valve header and yes it will cost more than the regular 2 valve lightning header.


sorry if i came off like it cant be done. there was a reason why sean hyland had a $12,000 price tag for a 4valve lightning motor back a few years ago. and due to lack of proper tuning the one motor i have heard of had blown. now the tuning processes have been refined and if you have the time and money its going to take to get the tune down then thats great. it definitely wont be something you can call the tuners up and say hey send me a chip for a 4 valve combo.


i've put alot of thought into the 4 valve swap and have consulted a few of the top racing engine builders that have built motor for some of the guys that run the nmra/ffw circuits.


all i'm getting at is it wont be as simple as just buying an intake and a set of 4 valve heads.

good luck to those that pursue this as it would be cool to see it happen but i'm telling ya you'll have $8-$10 grand wrapped up into the swap before you know it.

 

Cams will be twice as much but for most people the stock cobra cams will be enough. Front cam cover does not cost all that much I think it was around $100. Lightning braket is one thing that will have to be looked into. A new braket might have to be made. If you want to use long tube headers the cost might be higher or you could use the manifolds off a navigator. As far as tune a modified tune bassed off of the 03/04 Cobra should not be to hard for the tuners around here. As far as cost a guy should be able to do it for around 5grand maybe less depending on how he gets the heads. I might have around 8 grand into it but only cause I want to put the 3.3 whipple on it.

 

bump....

 

SHM had such high price probably due to the fact they used a almost 5000 sheet metal intake