Quote:

600 Ft Lbs at 2000 RPM is 229 HP, 600 Ft Lbs at 3000 RPM is 343 HP, at 4000 it is 457 HP, at 5000 it is 571 HP,.....a 600 Ft Lb motor from 2000 to 4000 RPM certainly sounds feasible....


Hi Guys,
Here’s hoping this post helps those looking for help and doesn’t create a poop storm for the others.
Before I get too deep into this I would ask that the readers read ALL of the story and not pick out small things out of context.
Yes, the numbers I used for my own engine do come from Desk Top Dyno, BUT, I have been using this tool for over 12 years in engine design work and know that if you feed it the truth, it tells you the truth within a couple of percentage points. This has been confirmed by other engine builders I know, and also by an engine test I just completed a short while ago.
This other engine is a 496 low deck stroker built to almost the exact same specs as my engine with two exceptions. The CR is 10.2:1 instead of 10.55:1 which is what I have in mine. The other is of course, the extra cubic inches. They both use the same heads, cam and Six Pack carburetion. The 496 has lighter, shorter pistons due to the longer stoke but that won’t affect performance on the dyno. For a point of interest, we ran a test with only the center carb and made 405 HP, then added only one outboard carb at a time time found that the max HP was available with just one outboard. The second one did not add any power. Of course, most of us with Six Packs just like the eye candy. If you haven't got a Hemi under the hood, a Six Pack is the nest sexiest thing, right?
Here are the numbers for the 496.
Desk Top numbers are first, then the real dyno numbers.
................ HP TQ HP TQ
RPM 3000 324 566 321 561
RPM 3500 381 572 387 580
RPM 4000 431 566 448 588
RPM 4500 470 548 489 571
RPM 5000 491 515 491 518

These are the only places where the two charts have similar RPM values. The max HP on the real dyno occurred at 4800 @ 496.7 HP . Max torque occurred at 3900 @ 590 lb/ft.
As you can see, the overall numbers were very close to each other and, actually the Desk Top Dyno numbers were a bit conservative. For those of you who think that the DTD is from fairly tale land have only seen results from people who enter garbage in and get garbage out. I use the actual facts of the engine as built and enter real flow numbers for the heads, not the generic stuff in the program.

Now for the numbers from my engine which seem to have stirred up a lot of conversation.
I am including the numbers from 2000 RPM to 5500, although I shift at 5000 due to the heavy hydraulic roller lifters and light valve springs and try to avoid any valve float.
............... HP TQ
RPM 2000 229 602
RPM 2500 288 606
RPM 3000 348 609
RPM 3500 403 605
RPM 4000 453 594
RPM 4500 499 569
RPM 5000 502 527
RPM 5500 496 474

Now, the naysayers can dispute the numbers at 2000 RPM and I won’t defend those numbers, for the reason is that my converter is a 2700 RPM stall and therefore I don’t see that RPM under load. However, all those that have ridden in the car both before and after this upgrade will attest that there is a huge amount of torque at those low numbers that wasn’t there before. I’m not talking about a bunch of chebbie guys that wouldn’t know torque if hit them on the head, I’m talking about lifelong Mopar guys who have been in many Mopar hot rods. I have 9.5” wide street tires on it and they are nowhere near enough tire.
For those who said they’d like a ride…. if you’re anywhere near me in the summer, you’re on. Rides freely given. The reason I claimed 515 HP is due to the 115 MPH speed at the track. If you enter that data into the accepted formula in the racing world, it equates to 515 HP at the flywheel. I hope that doesn’t start another controversy. Even if it is not 100% accurate, I can tell you that it is still a blast to drive and I can go well over 250 miles on a stock tank of fuel. That, my friends, is a fun ride.
As for the inevitable question of why my small engine makes more HP & TQ than the bigger one, that is something I struggled with during the computer design phase quite a bit. I ran the numbers many times to make sure I wasn’t missing anything, but finally came to the conclusion that the cam and heads are too small for the bigger displacement and are a perfect fit for the 451. Another small reason for the 496 real dyno numbers being on the light side may be that it is a fresh engine and could easily make more real power after a few hundred miles on the road. We also didn’t spend a lot of time tuning it on the dyno. This is a street engine and we weren’t after the last couple of HP at full RPM. This stroker is replacing a stock HP 383 in a 69 Sport Satellite and my buddy says “I’ll probably notice the difference”. For sure!
I am willing to share any of the finer details of either build with those who are genuinely interested, but please PM me individually. I will answer them as soon as the holidays are over. My family arrives in the morning, so I won’t be on here till after Christmas.
I also have the full documentation of the 518 installation in the Charger for those who would like it. It is well detailed and has several pictures. Will share.

7512512-P1160071.JPG (390 downloads)
68 Charger 451 / 518 65 Cuda 273 / 833 04 Cummins 2500 2WD 02 Grand Caravan