Has anyone ever built a fresh 440 six pack and 426 hemi using 100% factory spec parts...and dyno'd them?

any links?

I was curious as to how close the advertised factory hp/tq ratings were back then

Dulcich did a test in one of the Mopar Mags years ago w/ a stock 383 magnum and then a stock 440 magnum 4V. The 383 was about dead on 335 hp and the 440 was around 360 hp if I recall correctly.
Seems like I remember a similar test w/ a hemi, but not 100% sure.

Back then the factory dyno'd the engines without ant accessories being driven by the engine that would have robbed HP, that changed in the early 70's.

I don't see the magazines dyno testing engines with alternators, stock exhaust systems and air cleaners either so it should be a pretty fair test.

I built and dyno tested a stock stroke 440(446 C.I.) +.030 bore size 6 pak motor using forged TRW 6 pak pistons with LY rods and a little bit bigger cam, it was a street motor on pump gas with stock 906 heads and under 9.5 to 1 compression for the pump gas back then. It made 470 HP at 5400 RPM and , if I'm remembering corrrectly still, also more torque than HP
As fas as the factory going from gross HP at the flywheel with no accessorys to net HP with all the accessorys hooked up that was to lower the HP ratings for insurance rates I think GM started lowering the compression ratio in 1971 on all thier performance packages also, not sure about Ford. Mopar followed in 1972

I think that these things are easy enough to find.

Here is your list of factory HP ratings.

Please note: The race Hemi was also rated at 425 HP. This should raise a few eyebrows.

It may be that the advertised specs. were close to reality, as others have noted, these were gross HP ratings. Here is a good primer reagrding gross versus net HP ratings.

Here is a cool paragraph from the page:

"Gross output, which in the U.S. is typically measured using the methodology laid out in SAE standards J245 and J1996, is the output of a ‘bare’ engine running on a test stand with no engine-driven accessories (e.g., generator/alternator or oil pump), free-flowing exhaust headers with no mufflers, and optimal ignition timing. Gross ratings are also mathematically corrected for standard atmospheric conditions. In other words, gross output represents a particular engine’s maximum output under ideal conditions."

Yes, the page is brand X centric, but the principles are sound.

@ 5400 rpm it would of had 457 lbs ft of torque.

Me thinks you are using theorys and formulas for your estimate, not real world expereinces The last 30 or more stock stroke 440 motors I've built and dyno tested with pump gas and less than 10.5 to 1 compression ratio all made more torque than HP. The cam, intake, carb size and headers all affect the motor and what it does and makes on HP and torque On all of the low compression Stroker pump gas B and RB motors I've tested had the same results with either iron or aluminum heads My first 400 pump gas iron 906 headed stroker six pak motor made 612 HP at 5500 RPM and 644 Ft lbs at 4500 RPM on California 91 octane pump swill It ran faster in the car at the track shifting it at or above 7000 RPM So much for the theory of shifting it at or slightly above peak HP

Chill everyone. Cab didn't say at what RPM it made "more torque than HP". To me that just means it made 470 hp at some RPM, 5400, and (say) 500 ft-lb at some other, lower, RPM!

The torque and hp numbers are always the same at 5252 RPM, incidentally

Apples and oranges This is a good read! I don't think they even took into account air density or pressure back then and it is my understanding the torque to horsepower parameters for dynos have changed twice since then. http://www.badasscars.com/index.cfm/page...=prod/prd64.htm

No OIL PUMP??? That's hard to believe! Can any body confirm this? Seems kinda difficult to do for all the different configurations back in the day...

Ram Chargers had a guy that did the atmospheric calculations when they were testing. Although the car may have run slower in the afternoon, he could calculate that it was actually a better tune.

He (I believe his name was Al) was at the Indy banquet last march at the trade show.

Now, did they use data like this in the dyno rooms? Don't know, but the Ram Chargers would know.

No oil pump also means no need for oil and the windage it creates!
I'm sure he meant WP.

In the old SAE standard there was NO accessorizes on
the engine... that later changed to what the engine
would normally have on it... alt, power steeriing and
anything else... yes it did have a oil pump running..
I dont recall if the water pump was part of the old SAE
standard... no fan either

I think I remember a mag having Landy build a 70-71 426 Hemi as close to stock as possible to see what it would dyno. It either made 460,485 or 490hp. I think it was an old Car Craft and they compared the Ford Boss 429, LS6 454 and an Elephant all #'s matching resto engines.