I have access to an original Chrysler engineering Hemi resserch and development report from the 1960s.
It has the homologated power curves, Volumetric efficiency, BSFCs, ignition curves etc etc.
I haven't glanced at it for a while- but from memory:
When the engine was tested with no air cleaner, laboratory exhaust, inlet manifold heating blanked off and optimised ignition and mixture at all full load points (What alot of Detroit boys call a 'Gross power curve'- the engine attained well in excess of 480 bhp,
but with an air cleaner, inlet manifold heat, but still with labortory exhaust it was more like 477 bhp.
They had to derate it for homologation purposes:
So with a full vehicle exhaust system, an ignition system closer to production, cooling fan and other stuff they got closer to 390 Bhp, with alternator, etc.
I was most amazed at the volumetric efficiency values they got (90% peak) and even the BSFC (brake specific fuel consumption values)- which even with a carb set up and poor cylinder to cylinder distribution due to the compromised carburetteur manifold, got a remarkable 255 g/KWH (about 0.42 lb/ hp-hr)
Most of the contemporary cars at the time homologated closer to the 2nd condition or even the first.
If you see how Hotrod magazine test- they never use an air cleaner or vehicle representative exhaust system or back pressure.
I've been involved in modern V8 engine development, homologating to SAE, EEC and DIN certification and by todays standards all of the engines from the late sixties would be very optimistic, as the intake system, a vehicle representitive exhaust system and and other anciliaries MUST BE included.
I'll see if I can dig the old report out-I aim to copy it and laminate it to stop further deterioration.
