My room mate and I have a bet going on weather or not the 400 was a big, or small block. Which one was it? Thanks.

 

Both. Hows that for confusing . There is the smallblock 400 which is more common as well as a BB 400 which I believe was a 396 factory bored .030 oversize creating 402ci but they dubbed it the 400. Also there are pontiac BB 400s. NOw you BOTH owe me some beer
CoryM

 

You both win!!! (or you both lose?! )

Poncho or Chevy?!

The 400 c.i. CHEVROLET engine is a small block --- same parts will fit from a 265 c.i. --> 302 --> 327 --> 350 --> 400 c.i..

Now PONTIAC builds (used to) a 400 c.i. engine that's a "big-block" design, similar to the 455.

Hope that settles it?!

 

In the Chevrolet world, only the small block 400 was technically referred to as a 400. The 396 was always referred to as the 396 even when it was bored out slightly around 1969 or so. In 1971, the bored-out 396 became the 402, as was its actual displacement. The reason GM did not rename the 396 to 402 in 1969 was because Chevrolet spent a great deal of effort and money into creating the legendary 396 Chevelle in the mid- 1960's, and they wanted to captilize on this reputation. By 1971, the musclecar era was rapidly coming to a close, so they used the term '402' at this point.

There was no big block Chevrolet termed a '400'. The closest to this is the 402.

Dave

 

I am glad the origional bet for the case of beer wont mean anything now. Thank for all of the replys.

 

chrysler had a 400 big block too

 

There were a few cars that were advertised to have a "Bigblock 400" In 69-70. The El Camino Custom 400, the malibu 400 and the Chevelle (not sure if this was called the chevelle 400 or not). Anyhow, the engines were indeed 402ci and these cars are pretty rare as far as I know. I believe the engine option was "LS3" and was available in a few different HP ratings. THere was also the "turbojet 400" again, a 402ci but I do not know much about it. I believe a few cars got the turbojet 400. No, there was never a 400ci BB ( i think) but they were badged as 400s from GM.
Cory

 

If you're talking Chevy, the 400 is definitely a small block. The bored over 396 big block was a 402, not a 400... however Chevrolet usually badged it a 396.

 

You got it. Chevrolet never badged a big block car with '400' emblems. It was the 400 small block cars that got those like the Biscayne or Impala, for example. The Chevelle would have been badged with 402 emblems, not 400. Don't mistake a model line number for the engine displacement.

For example with Dodges in the late '60s, the 'Coronet 440' was a model, not the engine option. Those cars actually came standard with a 383. It would say 'Coronet 440' in chrome strip down the back of the car, leading one to assume it had a '440' engine. The fact that you could actually order a 440 in the Coronet isn't the point in this particular example. There was also the 'Coronet 500' as well.

The LS3 is a 402 engine and was marketed as such. I believe the year the LS3 came out was 1971.

 

Ponitacs really aren't classified as big block or small block, but rather just as a pontiac, being the 301-455 are basically the same sizes externally.

an old wives tale used to be you went by valve cover bolts, 4 or less was SB, 6 or more was BB...

ya-gotta be old to remember that (and a 3/4" cam)

 

Do you mean 3/4 inch? or strictly a " 3/4 " cam? I've heard my dad talk about cars/engines/cams back in his day (when he had a '69 SS 350) and he said that in one of the engines he built for the car, he installed a "3/4 race cam" --- I guess they referred to cams as "stock", "1/4 race", "1/2 race", etc..

FWIW, his car ran 12.9 - 13.1 consistently with a ~12:1 350, 4-speed, but only 2.73 gears!! Imagine what a set of 4.10's would have done for it?!

 

Chevy 400= small block, no funny twists.

But the Pontiac 400 is NOT A BIG BLOCK. Its a pontiac or mid block. They used the same block for all their motors there you cant possibly have a big block because theres no small block. I believe the block is bigger than an SBC but smaller then a BBC.

Fords 400 is a modidied block, like the 351 modified block.

I just read in the new Hot Rod that GMC made a big block 400 that they put in the Sprints.

There you go

 

Talking about a "3/4 race cam" was the old-school way of saying "I run NAWSS". It was kind of a dumb term back then, and those who said it usually got razzed for lack of cam knowledge.

Not insulting anyone, just saying how I recall it back in the 1970's.

 

Off subject, I know

I usually ask where the rest of the cam is when told someone has a 3/4 race cam.

I cringe when I hear N2O referred to a Noss. I ask if they mean nitrous or an actual NOS set up. If they give me lip I'll ask if every intake is an Edelbrock or every ignition system is an MSD.