hello all,ive got 5.4 3v vct motor in my falcon(aussie sedan)ive put a turbo on it and its running about 10 psi.it made 335 rear wheel kw but unfortunately runs out of puff at about 3500rpm.my question to those that can help is simply will a pair of cams bring peak power up a little further in the rev range??say around 5000rpm?or do the heads need work done on them?no one over here in Australia has really dealt with this motor so information has been proven hard to find.thanks in advance Luke.

 

The 3V heads flow very well. Stock they flow 227CFM on intakes and 153CFM on the exhaust at .500 lift. Also, the stock cams are .432 lift and the duration at .050 lift is 175 I/198 E. In the 5.4, they make power to 5800 RPM's. In the 4.6, they make power to 6100 RPM's. If the motor is falling off at 3500 RPM's, you have other problems that is holding the engine back.

On another note, 335kw translates to 449whp. You are very close to the limits of the stock rods. They usually break between 450 and 500whp.

FWIW, on my 3V 4.6, I made 636whp at 6200 with the stock cams. I switched to Comp 127550's and made 711whp @ 6600 RPM's. I then ported the heads and the flowed 274cfm on the intakes and 184CFM on the exhaust. I then made 740whp at 6700 RPM's on 18 lbs of boost and pump gas.

 

[quote=Marc S;11001587]The 3V heads flow very well. Stock they flow 227CFM on intakes and 153CFM on the exhaust at .500 lift. Also, the stock cams are .432 lift and the duration at .050 lift is 175 I/198 E. In the 5.4, they make power to 5800 RPM's. In the 4.6, they make power to 6100 RPM's. If the motor is falling off at 3500 RPM's, you have other problems that is holding the engine back.

On another note, 335kw translates to 449whp. You are very close to the limits of the stock rods. They usually break between 450 and 500whp.

FWIW, on my 3V 4.6, I made 636whp at 6200 with the stock cams. I switched to Comp 127550's and made 711whp @ 6600 RPM's. I then ported the heads and the flowed 274cfm on the intakes and 184CFM on the exhaust. I then made 740whp at 6700 RPM's on 18 lbs of boost and pump gas.[/quote
cheers mate,im guessing it could possibly be the intake manifold then?they put a cast aluminium one on the tritons over here,fairly long runners.seems as though just the cams made a massive difference.awesome bottom end power at the moment,do you loose a bit with these cams?are they the stage 2 serious street?.yeah at the fly fairly close to 370-380kw.when it was natually aspirated these things run out of puff at 5200rpm,i had 3.7 diff gears whacked in when the kaaz was installed,as a result i lost a few miles through the gears when i hit the limiter so i had the limiter set at 6400,in saying this it only seen this through first and second as the power drop off wasnt as noticable but it definately made the car alot quicker off the mark.am i right when i say that the 5.4 is a windsor and the 4.6 a romeo?the heads are slightly different i think?where did you get the head work done at?and is it fairly pricey?ive busted a valve or a lifter or something as its running rough and its ticking its head off,i figured it might be a good time to get the work done.ive got alot of questions i need answers on.is there an aftermarket intake manifold for these things aswell?thanks heaps for the info mate,much appreciated.

 

I run a Ford restoration/speed shop. I had my engine builder at work port the heads and flow bench test them. The cost is roughly $1200.00 to port, grind the valves, surface and assemble. I would not recommend the big Comp cams for a truck or a daily driver. They idle at 950 RPM's and are difficult for most shops to tune. If you ran out of power at 5200 NA, with the turbo, your HP peak should be extended another 500 RPM's. I would first look at your exhaust for a restriction. It might be as simple as a clogged or damaged catalytic convertor. I am not aware of a better intake manifold for the 5.4. The ticking sound may either be a bad or dislodged cam follower or a bad phaser. If you have a bad phaser and it's stuck in the advanced position, that could be the cause of the 3500 peak.

 

could be a bad phaser,havent ever replaced them and the dreaded phaser noise is there between 1000rpm and about 2000rpm,well i hope its just the phaser,the tick is nearly a knock,its fairly loud,the noise coming from the back piston on the left hand side,the exhaust note has changed a little aswell,alot deeper then it usually is.exhaust should be fine i think,got some staino high flow cats that really flow well,got headers aswell.the turbo might be restricting the flow a little.this motor has done 185000kms,not sure what this equates to in miles.it hasnt exactly had an easy life.thanks again for the info.

 

turns out the issue was a bad lash adjuster,number 2 piston on your passenger side.the cam bashed the roller and the rocker arm up it self.the roller has got 2 to 3 mm movement,i replaced the rocker and all three tappets and now the engine sounds good as new,no rattles or knocks.i think this tappet problem could become a common issue by the looks of things.As far as the cam phasers are concerned,i cant hear a thing anymore so they must be still o.k.

 

Or too small of a turbo

 

That would be my guess.

 

i cant remember exactly what size turbo is on there,its a high flow i know that much and its actually made up of two different size turbos,i think but not 100% sure that it could be a t3 exhaust housing and a t4 inlet housing.if the turbo is to small will it choke up exhaust flow enough to be the problem??runs twin 2.5" into one 3.5" through turbo then splits back into dual 2.5" pipes.ive seen a couple now that a boosted and they seem to get asthmatic at around the same rpm i think.have read that stage 1 cams work well but stuffs the bottom end torque up a little.am i right to say that these heads are off the 4.6l mustang motor?or am i wrong?the inlet manifold is one thing thats different,over here they are cast aluminium and i wouldnt know if the intake runners are any longer or not.