40thgtfl

I have a question for you guys. The general conscience among the members of this site seems to be there is no reason to go above a stage 1 cam on stock internals. You cant “rev” the engine high enough to take advantage of the cams power band. This puzzles me because to my knowledge the 4.6 in a 2v has the exact same rods, pistons and other internal components as the 4v mach 1 which can be pushed to 7000 rpm right from the factory. Other than the block I see no reason that the 2v engine, with a set of heads and cams that breath, couldn’t me reved up to 7k as well with out causing catastrophic engine failure. I could see when using a power adder that the added stress of high rpm use could shorten the life of the rods and bearings, but in N/A form why couldn’t you push to 7k?

Quick Shot xMLx

The Mach 1 crank is forged on the manuals but not the autos. That's why the autos don't rev that high. I think that "is" the only reason it can spin that high. Not too sure though...

40thgtfl

That makes since, but i was under the impression that the rod bearings were the first things to pop on a 2v motor. seems like the crank wouldn’t be that big on an issue unless its a balance problem.

40thgtfl

bump

40thgtfl

no one wants to take a crack at it?

40thgtfl

bump

Silver99GT

I'm not an expert, but you should not work stock 2V valve springs over 6500rpms. Put a high rev valve spring kit on from Comp,replace them every 80k miles,and hope the powdered metal rods don't snap. As you probably also know, stage 2 cams usually start pulling at higher rpms than stage 1's. My 1's are rated 1800 to 6400 rpm for performance. Max hp came at 5200rpm on the dyno. A bit lower than 2's where I wanted it. No idea if this is helpful or not.

RC5522

While your all talking about cams on a modular. For whom have installed a new set how would you compare a cm swap on these 4.6's against doing a 5.0. I did the 5.0 cam swap it was tediuos work.Seeing as these cams are in the heads and more accessable do you see doing a cam swap as an EASY job ? Compared to non over head cam applications that is..

ben790450

You CANT put more than stage 1 cams on a stock engine. You have to have ported or aftermarket heads for stage 2 cams and you have to fly cut the pistons for stage 3 cams

40thgtfl

right,agreed silver and ben, what i am saying is if you had ported heads and stage 2 cams why couldnt you rev to 7000 rpm with out the rods braking if the same rods are in a mach 1?