birdman076

Torque gets you going, horse power keeps you rolling. Its that simple but the problems arise when trying to hook up all the torque to the pavement to get you going faster. If you build for torque, you don't have to spin the motor as hard because its all low end grunt. But now you have to worry about putting it all to the ground, then parts breakage becomes an issue. If you build for HP then you have to invest in high dollar high rpm parts, and now you suffer off the line, but come on strong on the top end. Usually $$$ will dictate the kind of build, and personally I'd rather deal with hooking up/ breaking suspension and chassis stuff, then having to fork out alot of cash for high rpm components. Then having your car feel like a dog and have a big top end charge lol that to me seems disappointing at the least. But hey thats my .02

pipeliner

Im kinda curious now. Since Hp is a calculation from torque, I wonder how much torque my lawn mower has. Im gonna go figure it out

angcobra

If you know the RPM of the HP rating then it is very easy. That will tell you the Torque at that RPM, even though the peak Torque maybe higer at a different RPM.

rsw007

just bore the 351 .30 over and that will be plenty of power with good street cam and heads

roundman

a 351 would be a better street engine IMO.

vfast

my head hurts after reading rd's post

83GT306

He he he...it's not dead 'til my part's said.

Definitely 351w over a 302 for a street engine.

This whole thing about Torque vs. HP will never end because some people will never understand anyway. Like some here said, if you notice a dyno chart, at 2500 rpms HP is only like 100-125, while Torque can be well into the 300 ft. lbs. or more range. So it's easy to see that a stout Torque curve is the main factor for moving your car quickly on the street.
It all depends on the camshaft selection you choose. You want one with enough grunt to move you off the line. And that will have to do with choosing the right duration with your compression ratio.
A good rule of thumb for a street cam is the least amount of duration @ 0.50, with the highest amount of possible lift, and a suitable amount of overlap (LSA) for cylinder filling.
A cam with less overlap (112-114 LSA) will be lazy off the line, but Torque will build slowly and peak later in the rpms while continuing to produce HP at high rpms as long as your heads and intake etc...can let it.
A cam with more overlap (108-110 LSA) will enhance cylinder filling off the line because it creates a scavenging effect, pulling in more intake charge because the intake and exhaust cam lobes on the same cylinder hold both valves open shortly at the same time. This will build Torque quicker in the rpms, but the Torque will peak sooner in the rpm range, although HP continues to climb the scale just as the less overlap cam.

The Torque and HP paths cross at 5250 rpms on a scale, and you'll notice that Torque is falling off while HP keeps climbing.

Well, for me, I'd go with the most possible Torque down low because HP is going to be there anyway if your heads and intake can support the climb at higher rpms.
A street car needs to be built for low end torque with a reasonable rpm limit (5000-5500).
Save the 7000 rpm cam for the Salt Flats, that's the only place you'll be able to use it.

dodgestang

Perhaps you should define high rev.

My 408c revs till and still makes power till 7k

Do you mean you want a motor thats is out and done by 5-5500...
or
Do you mean you want a motor that goes till 10k?

Its interesting the things you can do with a street car.

With a 4.11 or better gear in the back and an OD trans you would be surpirsed how easy it is to get to 6500 in a street car while merging....or passing....or just driving the way I do....and then lock it down into OD and cruise at a reasonable RPM.

83GT306

That depends on where you want your torque curve to start.
Does your cam start making serious torque at 2500-3000 rpms and then carries through to 7000?
That's why you'd need the 4.11 gear to get you moving off the line.

A cam that makes good power starting at 1500 rpms and rated for 5500 rpms is all a street engine needs.
With higher rpm cams you'll need to dump all kinds of extra money into stuff like stall converters, and gears etc...
I don't think many drivers rev and launch their cars from the stoplight at 3000 rpms. If they do, they're a public safety hazard.
And merging onto the interstate at 7000 rpms? You must be doing 100 mph by then. Not legal street driving.

But yes, a 408W will have alot of torque, though you shouldn't build an all out race engine for a daily driver.

But also the original poster here never stated whether or not it was a street or race engine, I just assumed street?

Either way, torque down low is good, and is what carries the car to the HP range, and like I said, the upper max rpm has to do with whether or not your heads, intake, and exhaust can support that max rpm.

I'm running a cam that is rated from 1500-5500 rpms and I've pushed it to atleast 6000 before, still making power. You can't expect to shove a high rpm cam in an engine that has all factory parts, intake, fuel, exhaust, etc...and attain the rpm the cam is rated for.

horseshoeing

I am going with Joe said. Hp power is for speed and torque is for a truck.