289 vs. 302 - Page 2

Rev · 03-09-2002, 05:45 PM

That quote should have included the first part.

"With everything else optimizd, the higher displacement will always win".

Rev

Ron1 · 03-09-2002, 08:54 PM

To make any motor RPM quicker, the key is in the weight of the rotating assembly. That's why people knife edge cranks, use crank scrapers or windage trays, titanium valves, titanium retainers and keepers..its all in the rotating mass. Regardless wether is a short stroke or long stroke, the same rule applies, get the weight out and get into your powerband quicker. Launch as close to peak torque as possible, and shift within 200 RPM of peak HP. Seems to work.

Ron

72grande · 03-09-2002, 11:09 PM

Quote:

Originally posted by Ron1
To make any motor RPM quicker, the key is in the weight of the rotating assembly. That's why people knife edge cranks, use crank scrapers or windage trays, titanium valves, titanium retainers and keepers..its all in the rotating mass. Regardless wether is a short stroke or long stroke, the same rule applies, get the weight out and get into your powerband quicker. Launch as close to peak torque as possible, and shift within 200 RPM of peak HP. Seems to work.

Ron

There are so many things wrong in this post I'm just going to pretend i didn't see it.

Ron1 · 03-10-2002, 12:16 AM

Why is it that every single professional drag racer use titanium valves, and alum. rods? Why do they use alum driveshafts..or in prostock do they use carbon fiber drive shafts? Why do they use hollow axles...get the weight out. It takes HP to spin a rotating assembly. The less HP required to spin the lighter assembly, the more hp goes to the rear wheels.
Why do big block engines not RPM quickly and small blocks do? It takes more power to move that massive rotating assembly...and it's wasted, not going to the rear wheels.
The theory of a 300 HP 289 at 3000 lbs= 10 lbs per hp, and the 300 HP 460 in a 3000 pound car is still 10 pounds per HP, but boys and girl, measure how fast the engine accelerates to peak HP on the big block vs the small. The small block will kick butt every time on the big block, because it has less rotating mass to accelerate, even though the HP is the same.

Ron

Or to simplify even more...I have 2 cars in my driveway...one is 2000 pounds and one is 3000 pounds...using 72grande as our power source to push both cars, which one to you think he will move first?

Ron1 · 03-10-2002, 05:34 PM

A few more questions 72grande...here is a location for the Dyno results of my last (naturally aspirated) 347 that I completed last October..
http://media.bigstep.com/shop/2/29/3...3350753206.JPGYou will notice it made 486.7 ft/lbs of torque at 5600 RPM and 604.6 HP at 7200 RPM. Where do you think you would set your launch RPM and your shift point?

Ron

Rev · 03-10-2002, 06:50 PM

As I said previously, higher displacement will always win "IF" the power peak is at the same RPM (and assuming normal aspiration). This is not just supposition, it's a known fact.

Rev

PKRWUD · 03-10-2002, 07:22 PM

This thread has gone in so many different directions, it's starting to resemble an octopus.

72-

Quote:

Yes the piston is moving faster in the 302 than the 289. BUT! the crank is still spinning at the same rpm!

...until the parts reach their maximum speed. Then the 289 will have a higher rpm. Look, I'm getting tired of arguing this with you. You are very creative, but wrong. Facts are facts, and theories are theories. What I'm telling you is scientific fact, and I've already given you the name of one book that verifies this. I enjoy helping people here, but my time is worth more to me than to debate something with someone who won't accept the facts.

Good luck.

Take care,
-Chris

Rev · 03-10-2002, 07:44 PM

Does anyone in ANY racing class destroke his engine to less than the rules allow?

Rev

MetalHead · 03-10-2002, 10:48 PM

I started this whole long thread with just a simple question, what is the difference between a 289 and a 302? And for all the resplies that have been added to this thread, i've gotten very little feedback for my question. so far all i've been told is that the difference is 13 cubes and the stroke length of 2.87'' and 3.00''. Is that the only difference? What are the benefits of stroking an engine? Please try to stick to the point when answering. thank you all, i've had fun reading your responses.

Jason

Ron1 · 03-10-2002, 11:34 PM

The benefit of stroking an engine lies in the amount of torque the motor will produce. Torque being that ,which gets then car moving down track. The point in the RPM range where peak torque is developed and the point where maximum HP is developed, are dictated by how the displacement is built. As the stroke increases the lower in the RPM range the peak HP and torque will occur. However, a longer stroke motor will produce less peak HP but more peak torque. Short stroke engines produce peak power levels at a higher RPM and can produce a higher peak power, but less torque. You have to make a decision on how your motor will be built based on your vehicle weight, a standard or auto trans, gear ratio's and the rest.
As an example, I race a fairly light car, and leave at a fairly high RPM (5400) , so I do not need a whole bunch of bottom end torque to move down track. (BTW, I can compensate for less bottom end torque by adding something like N2O).
A heavy car, with an automatic for example, needs a lot of bottom end torque to get rolling, if it doesn't have it, it will not perform well.
David Vizard has an excellent book available..."How to build HP" volume 1&2, worth while reading.

Ron

MrWesson22 · 03-11-2002, 06:06 PM

On a street car, try to make as much lowend torque as you can hook. In the real world, all other things equal, a 300hp 460 will smoke a 300hp 289 because of the huge torque difference. There's an old saying - "Horsepower sells cars, but torque wins races". Destroke an engine to rev to the moon, and you've effectively made a larger, old tech, honda V8. Stroke it, and you've made your smallblock much more like an old school big block (ie 427cid windsor vs 427 side oiler). In a street driven 289 vs 302, it's not going to matter. There really isn't going to be enough difference to really feel. If you want to go stroker, it's better to get a 302 block because of the longer sleeves. The only differences between a 289 and a 302 are the length of the stroke, as discussed before, and the actual length of the cylinders. There's no problem putting a 302 reciprocating assembly in a 289 block, or even something like a 331, but I wouldn't personally put a 347 or 355cid stroker kit in a 289 block when 302 blocks are so cheap and easy to come by.

Rev · 03-13-2002, 09:42 PM

If you can get the 302 to make peak power at the same RPM as the 289, the 302 will make more torque and more HP. I'll second Ron's recommendation for David Vizard's book. Another good book is DESKTOP DYNOS by Larry Atherton.

Rev

Ron1 · 03-13-2002, 10:25 PM

What happened to 72grande? I have been waiting for his recommendation on my launch RPM and shift point RPM....

Ron

Rev · 03-13-2002, 10:52 PM

Maybe he reconsidered?

Rev

03-09-2002, 05:45 PM	#21
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	That quote should have included the first part. "With everything else optimizd, the higher displacement will always win". Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

03-10-2002, 12:16 AM	#24
Ron1 Registered Member Join Date: Sep 1999 Location: Vancouver, WA USA Posts: 439	Why is it that every single professional drag racer use titanium valves, and alum. rods? Why do they use alum driveshafts..or in prostock do they use carbon fiber drive shafts? Why do they use hollow axles...get the weight out. It takes HP to spin a rotating assembly. The less HP required to spin the lighter assembly, the more hp goes to the rear wheels. Why do big block engines not RPM quickly and small blocks do? It takes more power to move that massive rotating assembly...and it's wasted, not going to the rear wheels. The theory of a 300 HP 289 at 3000 lbs= 10 lbs per hp, and the 300 HP 460 in a 3000 pound car is still 10 pounds per HP, but boys and girl, measure how fast the engine accelerates to peak HP on the big block vs the small. The small block will kick butt every time on the big block, because it has less rotating mass to accelerate, even though the HP is the same. Ron Or to simplify even more...I have 2 cars in my driveway...one is 2000 pounds and one is 3000 pounds...using 72grande as our power source to push both cars, which one to you think he will move first? Last edited by Ron1; 03-10-2002 at 01:28 AM..

03-10-2002, 06:50 PM	#26
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	As I said previously, higher displacement will always win "IF" the power peak is at the same RPM (and assuming normal aspiration). This is not just supposition, it's a known fact. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

03-10-2002, 07:44 PM	#28
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Does anyone in ANY racing class destroke his engine to less than the rules allow? Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

03-10-2002, 10:48 PM	#29
MetalHead Registered Member Join Date: Feb 2002 Location: Monterey, CA Posts: 76	I started this whole long thread with just a simple question, what is the difference between a 289 and a 302? And for all the resplies that have been added to this thread, i've gotten very little feedback for my question. so far all i've been told is that the difference is 13 cubes and the stroke length of 2.87'' and 3.00''. Is that the only difference? What are the benefits of stroking an engine? Please try to stick to the point when answering. thank you all, i've had fun reading your responses. Jason __________________ 67 Coupe 289, 2 1/4'' pipes w/ Flowmasters Edelbrock 600 cfm 4bbl carb, Edelbrock Airgap intake Hooker headers, MSD Ignition system Next: new tranny, T5 or Toploader

03-09-2002, 08:54 PM	#22
Ron1 Registered Member Join Date: Sep 1999 Location: Vancouver, WA USA Posts: 439	To make any motor RPM quicker, the key is in the weight of the rotating assembly. That's why people knife edge cranks, use crank scrapers or windage trays, titanium valves, titanium retainers and keepers..its all in the rotating mass. Regardless wether is a short stroke or long stroke, the same rule applies, get the weight out and get into your powerband quicker. Launch as close to peak torque as possible, and shift within 200 RPM of peak HP. Seems to work. Ron

03-10-2002, 05:34 PM	#25
Ron1 Registered Member Join Date: Sep 1999 Location: Vancouver, WA USA Posts: 439	A few more questions 72grande...here is a location for the Dyno results of my last (naturally aspirated) 347 that I completed last October.. http://media.bigstep.com/shop/2/29/3...3350753206.JPGYou will notice it made 486.7 ft/lbs of torque at 5600 RPM and 604.6 HP at 7200 RPM. Where do you think you would set your launch RPM and your shift point? Ron

03-10-2002, 11:34 PM	#30
Ron1 Registered Member Join Date: Sep 1999 Location: Vancouver, WA USA Posts: 439	The benefit of stroking an engine lies in the amount of torque the motor will produce. Torque being that ,which gets then car moving down track. The point in the RPM range where peak torque is developed and the point where maximum HP is developed, are dictated by how the displacement is built. As the stroke increases the lower in the RPM range the peak HP and torque will occur. However, a longer stroke motor will produce less peak HP but more peak torque. Short stroke engines produce peak power levels at a higher RPM and can produce a higher peak power, but less torque. You have to make a decision on how your motor will be built based on your vehicle weight, a standard or auto trans, gear ratio's and the rest. As an example, I race a fairly light car, and leave at a fairly high RPM (5400) , so I do not need a whole bunch of bottom end torque to move down track. (BTW, I can compensate for less bottom end torque by adding something like N2O). A heavy car, with an automatic for example, needs a lot of bottom end torque to get rolling, if it doesn't have it, it will not perform well. David Vizard has an excellent book available..."How to build HP" volume 1&2, worth while reading. Ron

03-11-2002, 06:06 PM	#31
MrWesson22 Registered Member Join Date: Sep 2000 Location: Dacula, GA Posts: 73	On a street car, try to make as much lowend torque as you can hook. In the real world, all other things equal, a 300hp 460 will smoke a 300hp 289 because of the huge torque difference. There's an old saying - "Horsepower sells cars, but torque wins races". Destroke an engine to rev to the moon, and you've effectively made a larger, old tech, honda V8. Stroke it, and you've made your smallblock much more like an old school big block (ie 427cid windsor vs 427 side oiler). In a street driven 289 vs 302, it's not going to matter. There really isn't going to be enough difference to really feel. If you want to go stroker, it's better to get a 302 block because of the longer sleeves. The only differences between a 289 and a 302 are the length of the stroke, as discussed before, and the actual length of the cylinders. There's no problem putting a 302 reciprocating assembly in a 289 block, or even something like a 331, but I wouldn't personally put a 347 or 355cid stroker kit in a 289 block when 302 blocks are so cheap and easy to come by. __________________ Neal 69 stang 351C/4sp

03-13-2002, 09:42 PM	#32
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	If you can get the 302 to make peak power at the same RPM as the 289, the 302 will make more torque and more HP. I'll second Ron's recommendation for David Vizard's book. Another good book is DESKTOP DYNOS by Larry Atherton. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

03-13-2002, 10:25 PM	#33
Ron1 Registered Member Join Date: Sep 1999 Location: Vancouver, WA USA Posts: 439	What happened to 72grande? I have been waiting for his recommendation on my launch RPM and shift point RPM.... Ron

03-13-2002, 10:52 PM	#34
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Maybe he reconsidered? Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe