Big block ,Small block

[LeighP]

When talking GM and the "small and big block" thing....please do not lump PONTIAC under that GM umbrella.
PONTIAC traditional V8s are neither small or big blocks. All PONTIAC V8 engines share the same external dimentions (except the 301 which is a short deck block).

[DocJr]

Interesting things to remember: 1960's "Experimental Engines"

Olds had an all aluminum 455 DOHC Hemi that would have killed "Chrysler's 426" which later became the Aurora V8 (and Indy version).

Now sure, don't get your panties in a bundle over my sly comment above, we may never know everything that was under Chrysler's sleeve...or anyone else's sleeve for that matter! HAHA All in fun guys!

but yea, back to question at hand....I think everyone's just taking their best stab at this question, I for one never understood the concept, I don't really care either.."is that a small or big block?" Who cares?? its got a lot of power!!

[MonzaRacer]

Well now on Pontiacs part they could be considered a big block, but manufacturer wise they never needed a second engine, the Indian is already a torque engine, just very few in 50s-60s-70s paid attention.
My machinist was winding a 400 Pontiac ,with arma cast rods, over 8500rpm in stick car. I have the hard chrome crank and old school Echlin dual point dist too.
Pontiacs can be built to make well over 500lb ft of torque and never exceed 5500 rpm, Caddy was the same way. They built torque engines to pull heavy cars.
Buick and Olds did similar things, now GM got funky with the 215 sharing bottoms ends, being aluminum, etc. That stuff came over from Europe but never caught on big, what you want in your Camaro,Firebird,etc? 215 v8 all aluminum or a 302/396/427/454 or 389/400/428/455?
Remember Vega engine fiasco(ie you need new sleeves your aluminum cylinders are worn out sir) Same tech came from 215 program, just aborted for the V8 cause aluminum is too soft, cylinders ovaled out in few minutes.
Olds differentiated by cubes, ie 350 was "small block" 455 was "big block" and while share architecture they dont share many if any parts, Buick did similar ideas. And Caddy , well they just built big torque engines to pull fancy land barges (but then the 02 RSE Caddy Schwartz Perf built was awesome, pattern for my Caprice).
Now GM ,well Chevy tried to build a big block in 50s, 348/409, but had limited yet memorable success.
Now ford just made new designs, Y block in 50s, then the Windsor block from 221ci through 351, racing brought out a second Y block in the FE engine which gave us the infamous 427 side oiler and it kissin cousin the SOHC 427, Racing also gave us 351 Cleveland which did shar some architecture with Windsors(remember Boss 302/351) many a then donated heads/intake to be adapted to Windsor , the Modified engines came from emissions strangled Clevelands, and the venerable Boss 429 and of course the venerable Lima engine in 429/460, with few *******s in mix.
AMC never had BIG trucks so no, thay never had big block or small block, and AMC always had cool cars yet was a scrape together company till absorbed by Chryco.
In todays world if you can build it to make torque, ie air flow its gonna run good.

[ArtosDracon]

I've always wanted something with one of Caddy's big blocks, I mean a factory direct 500? Hell yeah! 4.3" bore, 4.3" stroke and 550lb/ft of torque, gotta love it. It's too bad they weigh almost as much as my truck.

[Drewcrane]

When talking GM and the "small and big block" thing....please do not lump PONTIAC under that GM umbrella.
PONTIAC traditional V8s are neither small or big blocks. All PONTIAC V8 engines share the same external dimentions (except the 301 which is a short deck block).

aah haa see im a Mopar guy and dont know about GM,very much,(one of the reasons i posted this thread), but now that you mention that i guess i have heard that ,and buick motors are different too right?,so Pontiacs are like AMC,S wit the same outer dimensions on most of there engines

[thumperamx]

aah haa see im a Mopar guy and dont know about GM,very much,(one of the reasons i posted this thread), but now that you mention that i guess i have heard that ,and buick motors are different too right?,so Pontiacs are like AMC,S wit the same outer dimensions on most of there engines

AMC ..... YES & NO
The early AMC 287 & 327 engines were small cube eingines but , they had a larger physical size then the Later series , they are a small block . These early engines looked simular to the Ford Y-Blocks (272, 292 & 312) .
The 290 thru 401 series all shared the same engine design and outside demensions are the same , also many parts interchanged . This series is a Small Block also , even the 390 & 401 and NO , AMC did not use a Ford 390 . The AMC 390 & 401 used the same bore , the 401 had a longer stroke . The 390 & 401's weighed 35 or so pounds more due to the cranks , rods and heavier webbing in the block , the Special 360 Block also had heavier webbing . The 290 , 304 , 343 & 360's had a smaller rod journal than the 390 & 401 , all used the same main journal size . The block deck height was raised in 1970 . This engine series ran from 1966 untill the end of AMC's production , full size Wagoneer V8 .

[79-TA]

but in theory the more reciprocating mass will result in more torgue/hp right? with a true 440,block, crank,rods,pistons etc?

More mass to move means more energy is required just to keep the engine components in motion. That means less power to the flywheel and ultimately, the wheels.

Torque is a result of the force being applied on the pistons from the combustion process. A heavier rotating assembly will have more momentum and will be less susceptible to losing rpm and bogging under a sudden load, but no extra peak torque will be created just by having a heavy rotating assembly. The extra mass will actually take extra force to accelerate and move at the same rate.

A heavy rotating assembly is only desirable for durability and perhaps hard drag racing launches.

Big blocks are about cubic inches, not mass . . . though they certainly are massive. The more volume the engine has, the more vacuum it can produce at whatever given rpm which lets it suck in more air which lets it burn more fuel which lets it make more power.