Performance 4.7 suggestions

[southlandmechser]

My 2003 Ram 1500, 4.7, NV3500, 3.55:1, just blew the water pump. I replaced it and it seems I'm now blowing coolant out the exhaust. I've decided to take the opportunity and rebuild my trucks entire drive-line. The NV3500, 5-speed, transmission is less than two years old and I hope to keep that.

BTW: I've been a mechanic for 35+ years

As every engine is different and I've not done a performance build on a 4.7 I'm asking for suggestions from experienced 4.7 builders.

So far, I have determined that I need a 4.56:1 rear, 2-1/2" dual exhaust with crossover (no converter), exhaust headers, new universal joints, transmission seals for good measure, and a heavy duty clutch.

This said, I'd love some suggestions on how to build the engine and where to get the components necessary. Seems there is not a lot of performance products out there for the 4.7. I'm looking for about 300 hp as that's all the NV3500 handles I believe.

 

[hotkarl]

You can't overheat a 4.7 even a few minutes. Hell, even running a little warm for an extended period of time will kill them.

Anyway, not much there for a 4.7 at this time. A few bolt on things and a tune and that's about it. You can break 300 horse, not hard to do.
If you can find the elusive and near extinct 4.7 HO cams that helps quite a bit in the big picture. Headers are kinda a waste of money. The stock manifolds are actually pretty damn good and flow very well.

Others will chime in with what can be done.

 

[Joe w.]

Do you know what the difference is between the heads and rest of motor on an 08 4.7 and your motor. I know they have 310hp maybe you can build your motor to its specs then add some bolt on mods.

 

[xb1230]

Just swapping the intake manifold from the original to the HO makes all the difference in the world, but they are very hard to find. There are a few freaks that have done some Supercahrgers and Turbo mods but they are few and far between.

The folks I would look to are AIRRAM. They have gone over the fence on modding and enhancing the 4.7L and they provide a lot of information on their WEB site you can have a look without it costing any $$$, so being a mechanic you will understand what they are talking about.

As mentionned, there is little to gain on these engines from porting the heads or changing the exhaust manifolds. For major enhancements you almost have to go stage 2 or even 3.

Good luck and keep us posted on your work.

 

[HemiLonestar]

Since you're going to have it ripped apart, it would be a good time to see if there is piston to valve clearance with the newer heads (you could try different pistons to see). I don't know if anyone has successfully proven one way or the other. I do know the 08 cams are on par with the old HO cams, but from what I've heard they don't bolt into the older heads. If the newer 4.7's are 310 from the factory, a good custom tuned retrofit would probably good for a little more; with a stick I daresay it'd be a blast to drive.

 

[rph74]

As the owner of a 2008 with the 4.7 HO and 6 speed manual, it is indeed a blast to drive!