What does it take to have a higher revving motor?

[OneStiffGT]

What needs to be done to a 1999 GT 4.6L motor so it can rev upto 8,000rpm but also, have a nice powerband that will go upto 8,000rpm?

Is it basically a matter of some headwork and cams (and offcourse tuning), or does the block have to be wroked on as well?

 

[stangGT97]

if you want to rev to 8000 safely, you will need a forged cobra crank and forged rods/pistons. to have a useable powerband, you'd need aggressive cams w/ matched valve springs, heavilly ported heads, an aftermarket manifold, full exhaust and all the boltons. A 302BB block will also help you reach your goal, they love to rev

 

[OneStiffGT]

How high can a stock block safely rev upto? Given that the appropriate headwork/cams are acquired.

 

[stangGT97]

How high can a stock block safely rev upto? Given that the appropriate headwork/cams are acquired.

6300ish is as high as i would take it

 

[BooWFO]

better question WHY do you want to rev to 8000 rpm???

 

[[Twitch]]

8250 redline in V8 = Audi RS4 4.2 V8

I wish our motors could rev that high

 

[OneStiffGT]

better question WHY do you want to rev to 8000 rpm???

So you can have a nice powerband, specially if you are road racing it is a good thing to have.

 

[tomustang]

So you can have a nice powerband, specially if you are road racing it is a good thing to have.

Corvettes do not have a high rpm band and they road race fine. You don't need high revs to be fast

 

[OneStiffGT]

Corvettes do not have a high rpm band and they road race fine. You don't need high revs to be fast

Thtat does not mean that, they wouldn't do better if they revved higher.

 

[BooWFO]

Thtat does not mean that, they wouldn't do better if they revved higher.

it's a v8, and an american v8 at that. Torque is what is good to have. For example if I have 500ftlbs of torque on hand at 2500rpm and a table top smooth band with only 20-40ftlbs of lose to say 5800rpm that gives me a useable powerband of 3300rpm right? Ok there is this thing called a transmission and a shifter USE it to keep in the powerband. Whereas the guy with a 8k engine where is his torque peak?? I'm going to guess closer to 5 or 6k and he is going to have to keep the rpm's up in order to stay in that band. Which takes alot more attention to the engine not to mention the increased cost of the powerplant.

Now things to consider if your serious about it. Your going to need a good bottom end. I'd suggest an explorer block ( the AL ones), a forged crank, forged rods, forged pistons, and al the necessary other things. Such as have the oil holes chamfered, and radius, block stress releived, good oil pump (cobra pump maybe? ). Then on to the topend, your going to need heads that flow like crazy, and I'd suggest a custom cams, cause I serously doubt anyone makes one with 8k rpm in mind for the 4.6 sohc. I'd also suggest a new intake, reichard racing or a custom job, maybe the one from MM&FF build up? . Find a tuning shop that will tune the cr to 8k rpm. Then your going to want to lighten everything you can so you can get the car into the powerband. ie Ti valves, retainers, AL, flyweigh, CF dS, dump as much weigth off the car as possible too. ie replace panels, ditch anything that you can.

Or get a dohc car.
Or more power available sooner ie poweradder. Turbo would be my suggestion

 

[damacman]

OK, so now that we've given him all the reasons that he shouldn't do what he wants to know how to do, does anyone actually know how to get the 4.6 to rev?

I too would be curious. NASCAR employs good ol' american V8s as well . . . and they make power up to 8k or so.

This may be my single biggest peeve of forums . . .

Q. How do I get bigger tires under my car?

A. Why would you want to do that - it's dumb.
A. You don't need bigger tires, my buddy has small tires and it works fine for him.
A. There was this guy my friend knew once and he tried that and it SUCKED. You're a moron if you try it too.
A. Dude, you don't need bigger tires, you need 4.10s.
A. Bigger tires huh? Are you sure you want to do that? What's wrong with the tires on your ride now. If you can give me some more information, I'll be happy to further illustrate that I can type with the best of them because I'm really getting my post count up under the guise of looking like an expert.
A. Second reply from same guy . . . On second thought, maybe some bigger tires will work for you . . . (got another free post . . .)

So, I challenge you all to answer the question . . . because I'd like to know as well.

 

[mity2]

when you build high rev motor, you'll generally move power band up high as well. I'd rather have low end grant

 

[stangGT97]

So, I challenge you all to answer the question . . . because I'd like to know as well.

a couple of us did try to answer it

 

[thomas91169]

you will need a valvetrain assembly capible of lasting at those revs, as well as a lighter and more capible rotating assembly(forged pistons/rods/crank). you will also need some very free flowing heads and cams to get the air the motor needs at those rpm's, or some sort of forced induction.

IMO a high revving V8 would love a large turbo(or two).

 

[merc123]

When I built my race car motor to sustain RPM's over 5k and up to 8k we put in a steel crank, steel rods and a hell of a cam. We have racing rockers and rods.

 

[Metalli485]

To build a high reving 4.6 you'll need one of these $, one of these $, and probably one of these $

 

[merc123]

Maybe a few more of $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

 

[BurningRubber]

Not posting not to answer the question...

But you should think of how much of a turd that engine would be in the lower range. It would probaly be comparable to driving a Honda with vtec or something at that point. Before way up in the power band when vtec kicks on, its slow and boring. Once your there then it comes to life, but you have to keep it up there so it will make power.

So for a daily driver that would be pointless IMO. If its a straight race motor thats gonna see those RPM's then yeah, you could do it. But... we all know that N/A 4.6's dont make squat for power unless you dump in $$$$$$$$, and by that point you could have one hell of a super/turbocharged engine with all supporting parts to make it run like a raped ape.

 

[OneStiffGT]

So, a 5.4L Navigator motor would be a better platform to start off with?

 

[DocG]

because I'm really getting my post count up under the guise of looking like an expert. (got another free post . . .)

Not sure we all worry about our post count that much.


But I really just wanted the free post.