How does stroke length effect torque and other things like how quick it revs, and how far it'll rev.

 

Stroke effects torque because it moves the rod journal farther from the centerline of the crank. It's similar to using a longer wrench (like a breaker bar) on a stubborn bolt. It gives you more leverage.

But as you know, it's easier to spin a short wrench fast than it is a longer wrench. Same concept with the crankshaft.

Now...... if you used a lighter wrench, it would be easier to spin faster, which is why they sell lightened crankshafts, rods, and pistons.

Does that answer your question(s)?

 

O.K. So longer stroke = more torque less RPM & HP
shorter stroke = more RPM & more HP

Is this correct?

Ok so are the 383 strokers longer or shorter stroke?

What i'm looking for is a motor with monster torque that revs to about 6K. I know intake and heads have a large affect on this as well.

 

cam is another thing to think about. it helps determine your peak revs for each curve. the 383 has a longer stroke.... hence the name "stroker". now... i honestly thinkyou can get monster torque and higher revs. 6k is definitely achievable. i would think about using forged internals, whatever you do... stronger, and more durable under repeated punishment.

 

Thanks for the info it'll be very helpful. I'll start researching cams. I had planned on forged bottom end, maybe even a girdle. Do you think AFR 190's will allow 6K with the right cam? they'll have an HSR on top. Or should I go 200 or higher

 

6000 RPM with a 383 is easily dooable. The "safe haven" is 6400 RPM average. That's based on the piston speed of 4000 feet per minute, which is said to be the max of stock rotatin assemblies.

A 383 is a 350 block bored .030" over, and then a 400 crankshaft (3.75" stroke) is installed.

If you go to www.Mortec.com and look under their Bore and Stroke link, you'll see what size engines have what bore and stroke. That should help you decide what you want to do, and how you want to do it.

The way to find an engine size is...

bore x bore x stroke x .7854 x number of cylinders = CID

4.030" x 4.030" x 3.75" x .7854 x 8 = 382.67, rounded up to 383