Timberwolf

This didn't seem to belong in the computer and diagnostic forum, and I don't think anyone reads classic tech, so I came here. I would consider this advanced tech since it involves really speccing out the engine in it's smallest detail...

Let's run this combo on a couple different computer dynos and see what we get...I have Engine Analyzer 3.0, so I'll try it on mine. What do you guys get?
454 bored .060 over, standard stroke
Merlin Heads with Milodon 2.19 intake, 1.88 exhaust, 119cc combustion chambers,
Roller 1.7 rockers, roller mechanical lifters
11:1 compression, Forged pistons
Performer RPM Air Gap intake
Race prepped holley 750 (flowing 830 after mods) dual feed, dbl pump
Crane Cam 252/262 @.050 .680/.708 lift

And if you need car info, it's a 69 Camaro with prepped turbo 400 and 3000 stall converter, 3.55 gears
Let's see who gets what, and what mods make the best recipe for the above combo...

k, here is what I get... I had to use a single plane intake because they didn't have a performer RPM listed for the BB chevy motor. Also, exhaust I used is 2 1/8" primary headers, 30" runners, 2.5 inch race mufflers and full duals. Accessories included were steel fan and factory water pump.
On to the data...first, the analysis:


Analysis Report for Street/Strip Engine with Desired HP Peak at 6000 RPM

Peak Tq =587. @ 5000 RPM 1.26 Ft Lbs per CuIn
Peak HP =582. @ 5500 RPM 1.25 HP per CuIn

Maximum Tq/CuIn is 1.257 Ft Lbs/CuIn.
This is somewhat high, indicating good performance, but will
produce high cylinder pressures and temperatures.


Maximum Exhaust System Backpressure 'Exh Pres' is 1.1 PSI.
This is typical for a street/strip vehicle with a free flowing,
full exhaust system. To simulate open headers, select the
'Open Headers' from the Exh System Type combo box.


Maximum Intake Manifold Vacuum 'Int Vacuum' is 1.9 ''Hg.
This is somewhat high and is limiting air flow and HP.


Maximum Fuel Flow 'Fuel Flow' is 340 lbs/hr GAS.
This is equal to 58.1 gallons per hour of fuel flow.
For an injected engine with one injector per cylinder, you will require
at least 43 lbs/hr injectors.


Mechanical Efficiency 'Mech Eff' is 76 %
at the current Peak HP RPM of 5500 RPM.
This is somewhat low and represents a real power loss in this
engine's current operating range. This can be improved by paying
close attention to details in the Short Block Specs menu.

The Intake Valve Mach # 'MACH #' is .42
at your 'Desired HP Peak RPM' of 6000 RPM.
This is low and indicates perhaps too much intake cam duration.


The Maximum Average Piston Speed 'Piston Spd' is 4333 ft/min
at the Performance Calculations Maximum RPM of 6500 RPM.
This is EXTREMELY high (if you want to run this entire speed range),
requiring light, high strength reciprocating components.

A street/strip engine should limit Piston Spd to a range of 3000-4000
ft/min. However, even to run at 3000 ft/min or higher, you will need
'better than production', high quality reciprocating components
(connecting rods & bolts, pistons, etc.).

Maintaining low Piston Spd and Piston Gs are critical for 'keeping the
engine together'. OVER-REVVING PARTS BEYOND THEIR INTENDED LIMIT IS
UNSAFE FOR THE ENGINE, YOURSELF AND BYSTANDERS.


The Intake Runner Velocity 'Int AvgVel' is 305 ft/sec
at your 'Desired HP Peak RPM' 6000 RPM.
This is somewhat high and indicates you will need a larger Intake
Runner Diameter or larger Intake Port Diameter for less
restriction and stronger intake tuning.

For these engine specs, an 'Int AvgVel' of about 250 should work well.
If the 'Int AvgVel' is approximately 30-80 Ft/Sec higher than this,
you will likely improve torque below this RPM, but lose some HP.


The Inertia tuning of this intake is tuned to 5369 RPM,
which is close to your 'Desired HP Peak RPM' of 6000 RPM.
Since this RPM is about where the HP peak should occur, peak HP
should be good. If you specify longer and/or smaller diameter intake
runners, you will likely gain Peak Torque and lose some Peak HP.


At 4 different RPMs, Spark Advance 'Spark Adv' is retarded to avoid
detonation. Retarding Spark Adv does reduce performance, but allows this
engine to safely operate with this Octane fuel.


The % Exhaust to Intake Flow Capacity 'Total Exh/Int %' is 68.7 %.
This is somewhat low, and indicates you could improve performance
by improving exhaust valve flow and exhaust cam profile. The most
common 'rule of thumb' is to design for around 75% EXH/INT flow
capability.

End of Analysis Report

Now the Specs:

Pk Tq: 587 @ 5000 Avg Tq: 464
Pk HP: 582 @ 5500 Avg HP: 318

Just for fun I ran it again with 2.25" header primaries, a 4.25 stroker crank, and electric accessories (water pump and fan) and got some interesting numbers (makes me ponder what will come out of the garage in the spring):

Pk Tq: 636 @ 5000 Avg Tq: 509
Pk HP: 625 @ 5500 Avg HP: 428

JimMueller

Desktop Dyno doesn't give the detailed analysis, but I get:

598 HP @ 6000 (500RPM increments)
591 TQ @ 4500 ("")

Using the following setup:

Block: Chevy 454, 4.311 Bore, 4.0 stroke
Heads: BBC Performer 229cc, 2.19/1.88
Comp Ratio: 11.00:1 (95.23cc)
Induction: 830@1.5inHg, Gasoline, Single Plane
Exhaust: Large-Tube Headers with Mufflers
Cam: Roller lifter, 252/262 680/708 112LCA, 4* advanced

Switching to Large stepped-tube race headers and a 4.25 stroke changed the numbers to:

619HP @ both 5500 & 6000RPM
630TQ @ 4500RPM

Swapping in a BBC Victor 375cc gave me:

681HP @ 6500 RPM
646TQ @ 4500 & 5000 RPM

Timberwolf

I find it really interesting that the Victor made that much more power and all in the desired RPM operating range. The software I used did mention a high intake vacuum that could be reducing vacuum, but I had no idea it was that restrictive. I haven't looked much into them, do the Victor intakes come with a choice of rectangle or oval ports? I assume the Edelbrock heads you used for the simulation are oval ports. The 325cc runners are very impressive, and as I said, it really surprises me that it makes that much power under 6500 rpm. Does DD have dyno charts? I am curious how the curve looks from bottom to top. Are we sacrificing a lot of torque with a runner that large?

JimMueller

Just a caveat, I'm not real familiar with BB stuff...but I have no idea which shapes the Victor ports are available.

DD does provide dyno charts, I could e-mail them or fax them to do if you desire. I tried all the standard manifold types DD offered (single, double, tunnel, sequential...I think there were one or two others) and the single gave the best numbers.

Does EA3 offer some sort of iterator to determine optimal combinations? DD doesn't offer much granular control of the small details, like rod length, runner length, intake port flow, weights, etc. I'll send you my work e-mail address in private e-mail - drop me a line reminding me to send the data to you if you want it.