You might consider building a shorter stroke engine! Possibly a 302(4 inch bore X 3 inch stroke). HP could still be decent, but usually at a higher RPM compared to a 350. And you definately will have less torque! I have also built many NHRA Comp Eliminator engines that have even had strokes as short as 2.700 with a 4.060 bore. RPM is killer, but might not be practical for your application!

 

I was curious if anyone had a good setup idea/info on a 350 to achieve a higher HP rating, but keeping the Torque as low as possible. This may sound like nonsense but for my application on racing on ice with stud less tires it is exactly what I need Thank you for any input

Don't know what you have now nor what kind of performance you really need?

Games you can play are many. The cam and compression will establish the basic parameters of how much power and where it peaks. But you can change these characteristics with selection of manifold and port sizes, type and size of headers, etc.

You can for example build an engine with the oft cursed swirl port heads which will really boost bottom end torque but die off rather early in the RPM range. But you can push the rev range up with 1.6 rockers and or more cam. Or you can come the other way with big port heads and a small cam. But this isn't the best way to maximize the bottom end. For an early bottom end you want high port velocities with a some what aggressive cam say around 220 degrees measured from .050 inch lift. This lets the engine take advantage of overlap and a late closing intake much sooner in the rev range. The long duration cam will let heads like swirl ports rev longer before they max out. The hard swirl they create in the chamber really pumps up the torque at a low RPM peak. You want to keep the valves small 1.94 intakes no 2.02s.

You also want small diameter long tube headers 1-5/8s or 1-3/4 tubes. This keeps the exhaust velocity high at low revs so there's a lot of pull on the intake during overlap and the high exhaust velocity really helps low rev Blow- Down in the cylinder making room for the fresh charge.

Another head to consider is the 305, 416 head. I'd consider this a tuning option to see if the engine is better adapted to your needs with the 1.84 inch intake valve.

For an intake you want to stay with a dual plane something like the Edlebrock SP2P, these have been out of production forever but show up at swap meets and ebay.

Bogie

 

Timing Computer

The addition of a programmable timing computer would allow you to remove some advance at low end and midrange to avoid a big torque 'hit' and prevent wheelspin.

If your rules allow...

Perhaps playing with the springs & weights of the distributor would soften the midrange to get what you want.

 

Just curious, would it really matter how much HP you had? Traction is going to be the limiting factor. It seems like you could do the same thing with just a gear change.

I would also assume you would accelerate the same amount if you had a 400HP engine with 200 ftlbs of torque or if you had 200HP and 400ftlbs for torque. The values may not be exact but you see my point.

With that being said you would probably want to build a short stroke high revving engine. A 327 or if you had the money a 302.

Jordon

 

No, the 400 Hp engine will have twice the torque of the 200Hp engine WHEN GEARED FOR THE SAME ROAD SPEED at those respective power levels.

Engine torque is completely unimportant, the gearbox and differential both multiply torque. It is torque at the rear axle that matters, not engine torque.

An engine that developed only ten foot pound of torque but could reach a million rpm would still develop 1,900 Hp

An engine that develops 1,000 foot pounds of torque at a thousand rpm only develops 190 Hp

You can have your 1,000 ft pound of torque engine, and I will keep my ten foot pound of torque engine, I would blow your doors off because I had ten times your horsepower.

To answer your question, what makes a lot of low end torque, and high rpm power ? A positive displacement supercharger does, and particularly a screw supercharger fitted with a large and efficient intercooler.

 

Thanks for the info guys I think I will try to build something with a short stroke for this season. The concept for ice racing is obviously traction but with a low torque motor. While your wheels usually always spin when they do find some rough or crusty ice the must hit with the least amount of torque possible to keep from breaking free again. It's like when U had your first vehicle say a s-10 with a 2.5 or something and in order to leave some black on the pavement U had to start in the gravel and get your wheels spinning and pull out, and when you did your engine fell flat on it's face. Thats what I need.

 

Car is a 77 caprice four-door gears are 3.73's tranny is a th400 tires are custom retreaded with ultra soft compound to grip anything they can the tracks are always flat but the surface changes with every lap you get the rookies out there who go sideways around all the corners and "wipe" them clean. I don't blame them though I was there once. I have enough experience to control my car steering through the corners with the throttle; the same speed as the guys that take the top three places every weekend, but when it comes to the straight aways I can't keep up with the guys with more horse power. Also the rearend is my own custom spool fully welded and machined from old spider gears.

 

The average speed down straightaways is only about 50 in the corners it's probably only 20 or 25. It may not be fast racing, but it does take alot of technique one spin out could cost you the whole race and you might never catch up to anyone

 

use a cam with a very wide LSA (116+ degrees) to reduce peak torque and make the torque curve flat and long.

 

Thanks 454c-10 and everyone else, by the way I like your 70 c-10 I'm trying to find another 72

 

:smash:

Engine torque is completely unimportant

I need help with this. Really, I do. If the engine had no TQ to multiply, where then would your HP come from?

the rearend is my own custom spool fully welded and machined from old spider gears

I bet there's nary a maching mark! Classy!

 

yeah stroke I made quite a few "mini spools" for guys who race with me. The key to our racing fun is low buck when you can. I take the gears put them in a fixture and weld plugs in the available openings and finish by turning and milling it all down to look and fit better. It holds up a lot better than the traditional plain welding

 

I was curious if anyone had a good setup idea/info on a 350 to achieve a higher HP rating, but keeping the Torque as low as possible. This may sound like nonsense but for my application on racing on ice with stud less tires it is exactly what I need Thank you for any input

HP and Torque are mathematically linked by the equation; HP = TQ x RPM/5250. So, for a given engine, if you move the tq down the RPM curve, high end HP will drop and the opposite is true if you move the TQ curve up.

There are some things you can do to improve the overall torque, which not only benefits the low end, but if you can broaden that torque curve, you can extend the HP range a bit. Common ways to do that (depending on the engine configuration)

1) raise compression. On a dyno chart, raising the compression will take both the TQ and HP curves straight up.
2) increase head port flow without adding appreciable volume. Bowl blending/pocket porting is a common practice which (if done right) can increase flow more than you increase volume. High flow makes high HP. High velocity makes good low end torque. On a dyno chart this usually leaves the low end alone, but stretches both curves out to the right above 5250 RPMs
3) higher ratio rocker arms (provided you aren't lifting too high). On a dyno chart, this tends to lift both curves straight up by the ends leaving the middle alone.
4) forced induction/nitrous. On a dyno chart, this looks better than porn
5) wider LSA cam. On a dyno chart, this typically has the effect of broadening the curves; typically takes the right and left ends up, but the peaks in the middle come down.

The other idea (if done right) is adding cam duration in conjunction with proper head flow increases and compression ratio increases. This will raise the RPM at which the engine peaks its numbers, but raising the point at which the engine's torque peaks is not always a bad thing, either. Take a look at the picture below and you'll see that while the second engine in the graph has a higher torque peak RPM, it is still making almost as much torque down below, but the total average torque under the curve is vastly increased. Plus look at how much extra peak AND average HP you get up top. With a TH400 and 3.73s you could stand to take your torque curve up a touch and not be mismatched, but it should go along with a compression increase and improve head flow. Of course, it all has to be matched, and you have to be sure that the engine can handle the extra RPMs, but a mild increase in duration can produce better averages without killing the bottom end. The secret is choosing the RIGHT duration. The factory almost always selects a duration that is pretty small.

The other thing you really should take advantage of is head technology. Today's heads eliminate some of the trade-offs. In the past you had to have either port volume OR port velocity, but more modern heads (like Vortecs) have been shown to have far superior flow without having to resort to a huge port. Combine that with the fact that the combustion chambers in modern heads take advantage of new discoveries, and its totally a win-win. For instance, let's assume you have 8.5:1 compression with 76cc heads right now. Swapping on Vortecs with 64cc would raise that to about 9.5:1. Alone that can be worth 5+ hp without affecting torque. Add in the boost in flow and you have much more potential, and the modern chambers mean you don't have to run anything more than the 87 swill you put in it now. Reduce your overall timing to more like 32* instead of the factory 36 or 38* and you are set. Some folks are claiming a 30 hp increase just from a Vortec swap.

I know I sound like a broken record these days, but this build screams for Vortec.