Thread: Dyno Guys

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As much as I like to hear it, 443 ftlbs at 2500 rpm seems a little optimistic. The motor doesn't really come alive until 3000 rpm so I would think the peak torque is above that.

hi George... I think the big difference between our numbers came from the cam duration. Hopper said he's using a 242/242@.050 and you used 296/302 (seat-to-seat?). For heads, I used flow numbers for 441 and added 10cfm fudge to account for the larger valves. I think the Torker intake is limiting top end, too.

I ran again with new bore/stroke.... (BTW that comes to 379.7ci with 4.155x3.5")

With Torker ("dual-plane high torque") intake:

381hp@5000 / 479ftlb@2000-2500 (no change with bore/stroke)

With "RPM air gap-like" ("dual-plane max flow"):

446hp@5500 / 474ftlb@4500

That's a huge difference from the intake manifold.

-Chris

Originally Posted by Hopper111

I'm sorry, i did not specify bore and stroke. It's a 4.155 bore x 3.5 stroke

Destroked 400 SBC. The cam is a 110* lobe center.

What would the numbers be if i swapped over to a good set of AFR or Brodix heads?

Check this out at the AFR website:

http://airflowresearch.com/eliminator.php

I think it would be interesting to see someone who has run a motor (or a few motors) on an actual dyno post their specific configuration(s), and then run the config(s) through a dyno simulator and then compare the actual vs. simulated numbers to see how close the sim actually is to the real thing.

I have a desktop dyno sim and I have wondered how accurate the thing actually is. I realize of course that if you put garbage in, that's exactly what you'll get out of it; but, I would like to see how close they actually are with the correct info.

Cheers,
Dutch

Hey Dutch,

Absolutely... no thing like the real thing but as has been mentioned before it's good to have a tool that can approximately gauge the benefits (or lack of) for certain modifications before shelling out the dough for the real thing... basically helps to make better decisions in putting together a motor. I've not had my 'bird on a dyno yet but I put in the specs of my motor (as close as I can figure) and used those specs along with other specs of the car into Desktop Drag and it's predicitions for ET and mph are within less than a 1/10th second and exactly the mph of what the car actually runs with specific weather conditions. I think it would be great to see some comparisons between Desktop Dyno (or any other sim software) and real engine dyno results. I would not be surprised if the predictions were pretty close from the results I have so far.

-Chris

Can you guys run the numbers on that motor with a this set of heads and the Air gap intake please?

They are Renegade heads with 190 cc Intake runners, 64 cc combustion chambers and 2.02/1.60 valves.

OR

They are Renegade heads with 190-210 cc intake runners, CNC ported 69 cc combustion chambers and 2.02/1.60 valves. Thanks, I'm really sorry for asking so much, but i think i'm starting to get the drive to start work on my car again instead of selling it off.

Hi, Hopper. No trouble at all... I have a lot of free time this week. Wasn't sure if the flow numbers on the Renegade heads were for the CNC ported or unported variety so I ended up using same numbers for each and only changed the combustion chamber. I was assuming 10:1 compression with 64cc chamber so with 69cc chamber SCR came down to 9.53:1

All with "max flo dual plane" intake:

190cc runner 64cc chamber: 487hp@5500/498ftlb@4500
190cc runner 69cc chamber: 479hp@5500/489ftlb@4500
210cc runner 64cc chamber: 498hp@6000/502ftlb@4500
210cc runner 69cc chamber: 486hp@6000/492ftlb@4500

Of course flow will be higher with porting but I don't have all the info so this is best I can do... in other words either the ported results are pessimistic or the unported results are optimistic...

Have fun...

-Chris

Can you help me with the HP on your dyno with this configuration
Block-dart 9.325 deck, bore 4.125 cubic inch 427
Heads- AFR 227 68cc chambers int. 2.1 ext. 1.6 full race ported
crank- bore 4.125 stroke 4
carb- 750 demon
pistons -JE dish .115 comp 11.25
cam -roller int dur. 292 ex 302 lob sep 112
rockers -jessel 1.5 total lift int .604 ex .597
headers -1 5/8 pipes 3" H pipe installed
intake -performer rpm duel plane
elec -fan and water pump

Originally Posted by DADNOVA

Can you help me with the HP on your dyno with this configuration
Block-dart 9.325 deck, bore 4.125 cubic inch 427
Heads- AFR 227 68cc chambers int. 2.1 ext. 1.6 full race ported
crank- bore 4.125 stroke 4
carb- 750 demon
pistons -JE dish .115 comp 11.25
cam -roller int dur. 292 ex 302 lob sep 112
rockers -jessel 1.5 total lift int .604 ex .597
headers -1 5/8 pipes 3" H pipe installed
intake -performer rpm duel plane
elec -fan and water pump

You will have to say what the duration is at .050 is.

This motor with the flat tops and a 76cc head was going to be at 10:1 so I think with a 64 or 69 cc head, the compression will be closer to 11:1. How much of a power difference does 1 point in compression make?

Hopper,

If at 10:1 with 76cc, you'll be at 10.8:1 with 69cc and 11.45:1 with 64cc. Using the same 210cc intake runner heads:

10.8:1 -> 513hp@6000/513tq@4500
11.45:1-> 526hp@6000/522tq@4500

assuming same flow rate for all heads

-Chris

DADNOVA,

Here's a cut... not sure of your rod ratio this is a stroked 400 sbc, right? I used seat-to-seat for duration and assumed 110* intake centerline. Can't account for elec pump and fan...

507hp@6000-6500 494tq@4500...

garbage in-garbage out.... this should be in the ballpark.

-Chris

what type of fuel can i get away with in this motor if i were at 11.45:1?

I got a little carried away, i wanted a *street* motor and ended up building way too much engine. If i could go back i would, but unless someone buys this motor, i'm stuck with it. I shoulda built a big block

Originally Posted by Hopper111

what type of fuel can i get away with in this motor if i were at 11.45:1?

I got a little carried away, i wanted a *street* motor and ended up building way too much engine. If i could go back i would, but unless someone buys this motor, i'm stuck with it. I shoulda built a big block

I.M.O,I would either go all the way to 13 to 1 or go back to 10.5 to 1 for a comp ratio.
At almost 11.5 to 1 you will have to mix race gas with pump gas.
Yes it is a pain in the a$$.

[Can you help me with the HP on your dyno with this configuration

Block-dart 9.325 deck, bore 4.125 cubic inch 427
Heads- AFR 227 68cc chambers int. 2.1 ext. 1.6 full race ported
lift flow int ex
.2 138 112
.3 207 150
.4 258 190
.5 294 207
.55 298 213
.6 302 220
.65 305 225
.7 309 230
crank- bore 4.125 stroke 4
carb- 750 demon
pistons -JE dish .115 comp 11.25
cam -roller int dur. 292 ex 302 lob sep 112
Int duration 292
Ex duration 302
Int lift at cam .403
Ex lift at cam .398
Total lift int.604 ex 597
rockers -jessel 1.5 total lift int .604 ex .597
headers -1 5/8 pipes 3" H pipe installed
intake -performer rpm duel plane
elec -fan and water pump[
Does that help