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Hi Guys, New Aussie Member Just Wondering What Sort Of HP Outputs
Anybody Out Their Has made With A 331,354 Or 392 After A Build-Up.
Is 350HP Easy To Achieve With The average Aftermarket Parts And Is 500-550HP Achievable With Custom Bits, Pistons,Rods ETC. Thought I'd Ask Some Experts As Info And Parts Are Hard To Get Down Here. Thanks DREW.[/b]

Greetings Down-under. One hp per inch is easy, 500 is attainable but it will not be a grocery getter package. The biggest stumbling block is the cost of the parts to make big numbers. We simply do not have the plethora of parts that are available to other engines such as the 440 or the 426. Example; If you want a 4.5" billet crank it will be a custom piece and the price will be 4-5 times the 440 cost... ... The easy way to make 500 hp will be with a blower then you would have to try to keep it that low

Remember too that even back in the 1950's - some of
these engines came with *stock* horsepower ratings in
excess of 350 hp - notably 355 hp for the dual-quad
354 in the Chrysler 300 in 1956 - and 375-380 hp
for the 392s in the '57 and '58 300s and Imperials.
(390 hp for the ill-fated Bendix fuel-injected Imperial
392 in '58 too. Don't even bother looking for one
of these beasts, though! First, they only produced
a few hundred cars with the Bendix "Electro-Jector"
fuel-injection to begin with. Then, when this prematurely
released EFI system - the technology just wasn't
there yet - proved problematic, they were all re-called
by the factory and converted to dual-quads!)
These factory hp ratings were the old 'SAE Net' system
by the way, but with some modern parts - ie - a better
camshaft, upgraded ignition and exhaust, a modern
intake (like the Hotheads intake for example), modern
carb(s) or EFI, some head work and careful assembly and
tuning - it shouldn't be too hard to exceed the factory
'SAE net' ratings by a fair bit. 350 'SAE gross' shouldn't be
too hard to achieve and 400 probably do-able. More than
that though is going to get pretty expensive and probably
will require a blower and/or a lot of exotic, high-dollar
race parts. Good luck and have fun!

I'm planning a full disclosure (including some our monumental miscues) writeup on our 2007 Engine Masters Challenge 331 hemi. Hopefully I'll have some time in a week or so to put something together.

In a nutshell, we were trying for a maximum average torque 2500 to 6500 rpm engine, and were not even remotely concerned with peak power. Factory 331 block and crank, Hot Heads heads (stock Hot Heads valves), Eagle BBC 7.100" steel rods, 10.5:1 Ross pistons, 91 octane fuel, Engle flat tappet cam (239 @ .050", 107 lsa), dual plane Hot Heads manifold, older 4150 Holley, Hot Heads headers, Magnaflow mufflers.

I don't have the exact numbers at hand, but it made well over 500 horsepower (515 @ 6200 rpm comes to mind), didn't complain even a spec after over 80 pulls, and the last pull was the strongest. With a little more camshaft (maybe a hydraulic roller), a very streetable and dependable 550 horsepower should be easily attainable.

Tom Waters and Bob Walker (Hot Heads) are a valuable resource for parts and information.

Film @ 11. Danny

dan miller wrote:I'm planning a full disclosure (including some our monumental miscues) writeup on our 2007 Engine Masters Challenge 331 hemi. Hopefully I'll have some time in a week or so to put something together.

In a nutshell, we were trying for a maximum average torque 2500 to 6500 rpm engine, and were not even remotely concerned with peak power. Factory 331 block and crank, Hot Heads heads (stock Hot Heads valves), Eagle BBC 7.100" steel rods, 10.5:1 Ross pistons, 91 octane fuel, Engle flat tappet cam (239 @ .050", 107 lsa), dual plane Hot Heads manifold, older 4150 Holley, Hot Heads headers, Magnaflow mufflers.

I don't have the exact numbers at hand, but it made well over 500 horsepower (515 @ 6200 rpm comes to mind), didn't complain even a spec after over 80 pulls, and the last pull was the strongest. With a little more camshaft (maybe a hydraulic roller), a very streetable and dependable 550 horsepower should be easily attainable.

Tom Waters and Bob Walker (Hot Heads) are a valuable resource for parts and information.

Film @ 11. Danny

That would be awesome.