Since almost no one is hot rodding Packard V-8s these days (few ever did) and information from the factory is unobtainable, I decided to use modern computer engine dyno simulation software (Dyno2000 version 3.10) to get closer to an "optimum" equipment choice for my Panther engine. The major components that I can realistically vary (and parameters I can simulate) are these:
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To start with a simulation baseline, I'll assume the advertised HP &
TQ of a 1956 Clipper or Executive 352CID Carter WCFB 4bbl (385CFM)
with dual exhaust. We all know these
numbers were "gross" values and maybe were "tweaked" for advertising
purposes, but I'm only interested in RELATIVE performance. |
275HP@4600 & 380TQ@2800 Stock Advertised |
Plugging the stock parameters into the simulation software yields: |
251HP@4500 & 348TQ@3000 Baseline |
This is -24HP & -32TQ from advertised. This difference is probably due how Packard actually dyno'd their engines and the aforemented advertising pumpup of the numbers. Whatever...This is close enough for my purposes and is my BASELINE. All subsequent changes are deltas (usually additive) from these values. The following is a summary of what the dyno simulation claimed were the delta changes. |
CHANGING DISPLACEMENT from 352 CID to 374CID (simulate using dished pistons to keep the C.R. at 9.5:1 constant while increasing the displaced volume only) yields: |
253HP@4500 & 368TQ@3000 |
This is +2HP & +20TQ from BASELINE.
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CHANGING COMPRESSION RATIO from 9.5:1 to 9.56:1 (actual |
254HP@4500 & 369TQ@3000 |
This is +1HP & +1TQ delta. This no doubt means that the original C.R. was probably closer to 9.1:1. |
CHANGE CAMSHAFT from stock to Lazer regrind yields: |
277HP@5000 & 346TQ@3500 |
This is +23HP & -23TQ delta. |
Mildly modify heads with port match, flash removal and 3-angle valve job. |
295HP@5000 & 351TQ@3500 |
This is +18HP & +5TQ delta. This shows how much the cylinder head flow can be improved with relatively minor modifications. |
CHANGE INTAKE & from 1x4 stock (dual-plane, 385CFM) to 2x4 Caribbean (single plane, 2 x Holley 450CFM) yields: |
353HP@6000 & 372TQ@4500 |
This is +58HP & +21TQ delta. |
CHANGE STOCK EXHAUST MANIFOLDS to small tube headers (custom fabrication). |
--->413HP@5500 & 428TQ@4500<--- |
This is +60HP & +56TQ delta and +162HP & +80TQ from BASELINE. This shows how bad the stock cast iron "log" exhaust manifolds and probably the mufflers are. |
That performance will do, especially if it's anywhere near real!
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