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-   -   Small Block 400ci...or...Big Block 396ci???? (http://www.hotrodders.com/forum/small-block-400ci-big-block-396ci-3756.html)

chevyelc81 09-30-2002 07:08 PM

Small Block 400ci...or...Big Block 396ci????
 
Which one would you go with?? Ive got the small block 400 which im planning on building up with aluminum heads(2.08in 1.60ex), 6 inch rods and a roller cam. But... I was just teased on a deal for a 396 big block bored 30 over(which makes it a 402ci) and its all redone pushing 430hp. If I got it, I would probably put aluminum heads on it with big valves and a roller camshaft. It would be pushing well over 500hp, but same with the 400 if I built that. I plan on running a supercharger also. The car is a 69 camaro which orginally had a 396 in it. Im leaning twards the 400 because I figured its lighter, but I don't know much about 396 motors, Are they better than the small block 400? The 400 has a 4.125 bore with a 3.75 stroke. The 396 has a 4.124 bore (thats .30 over) and a 3.76 stroke. Theres not much difference there. Whats the big difference becides big block and small block? Which one would you go with??

78 monte 09-30-2002 07:11 PM

I personally have a fear of steam holes.That and I like saying BIG BLOCK so I say 396. Hows that for an informed decision???

41willys 09-30-2002 07:13 PM

Go with the big block and get the torque. Big blocks start making their power at lower RPM. Besides, if you plan on drag racing this car, torque is what you need for most of the track.

Then again, do what you want.

Jason

Deuce 09-30-2002 07:20 PM

If you have a factory big block Camaro........duh....put a big block back in it!

Real Factory big block Camaros have the two heater hoses coming thru the firewall almost under the hood hinge, small blocks over the valve cover. In fact , to put a big block in a small block 69 Camaro, you almost have to bend the hose outlets to clear the BBC valve covers.

chevyelc81 09-30-2002 07:32 PM

Well, the thing is that, Im using the car with the 400 small block mildly built, and im impressed with the power. This winter is when im going to decide on what engine to use. The heater hoses are almost right under the hood hinge and the front end sits really high, do to the big block springs. If I keep the small block, I will end up changing the springs, but you guy are telling me the 396 is better. I don't understand how they build better low end torque when they have almost have the same stroke and piston size, can someone fill me in?

dallam1 09-30-2002 07:46 PM

It's got to be those big block heads with the huge porcupine valve arriangment. However, I'm showing my age here but I remember very distinctly when the big block came out. It most certainly was the talk of the town. The 375 horse power model would kick butt but the 325 horse power model was said to not be able to take on many small blocks and was considered a bit of a dog. I had a 427 once in a Chevelle and it was strong but quite often (much to my dismay), hot 350 Camaro's would beat me but they had to work hard to do so. I bet however, if I would have ported those huge heads and installed a hot hydraulic cam in that thing, it would have smoked most 350 Camaros. My vote....Big Block!

Super Streeter 09-30-2002 07:51 PM

In stock form,a 396 has way more potential then a 400 smallblock.The worst stock 396 oval port heads ever made with stock little 2.07"intake valves and no port work with just a 3 angle valvejob will match or outflow even the best 23 degree head smallblock aftermarket racing heads.Bigblock bottom ends have way stronger components,and there are a few other good features.The bigblock has a larger diameter camshaft core,so most bigblock cams cam withstand more lift,and bigblocks come stock with 1.7:1 rockers,so you can get even more lift from that.In reality,even the mildest factory performance bigblock cams had .550" lift.The 396 has a better rod ratio because the stock rods are 6.135" long which is longer then almost any aftermarket 400 rod setup being offered in kit form,and the 396 stuff is stock.You can build a 396 with a stock 2 bolt main block,stock crank,stock rods with good bolts,stock replacemnt performance pistons,a stock GM camshaft{L78 solid lifter 396 cam would be real strong}with stock unported closed chamber heads with no porting,just a 3 angle valve job,stock rocker arms,pushrods,lifters and valvesprings,a performenr rpm intake,headers,and an 850 double pumper,and have a 500 hp engine that you can drive every day and be built with mostly stock parts,and shouldnt cost more then about 3 grand to build.The next idea is to not build a 396,but build a 454.You can find more 454's then 396's,and they come with even better stock heads,and they are externally the same,so you can dress it to be a 396 and nobody would know the differance.With a 468{.060" overbore}with stock heads with a good valve job,9.5:1 compression,and a mild cam such as a 280 degree Isky Mega cam,you can build an 11 second engine that will run on pump gas and not even sound radical.Add a 125 shot to it,and even the most mundane 2 bolt main cast crank 454 will be a 10 second beast.With aftermarket heads and a race cam you would be hard pressed not to make over 600 hp with either a 396 or 454,and that is with basically off the shelf parts.Good luck.

MHenricks 10-01-2002 06:01 AM

Go with 396, sb 400 don't have water jackets between the cylinders. I use to race a 73 camero with a mildly massaged 396 and it was great. Theres not alot to learn on big blocks, except when you mash your fingers you yell louder. More torque and hp for not much modofications.

Besides I like saying 396, 396, 396, sorry I got carried away.

insomniac 10-01-2002 08:22 AM

I can tell you that you will be doing yourself an incredible injustice if you dont put a 396 back in an origional 396 camaro. They are worth so much...

But in camaros, 396's were pigs. They make the front end all sluggish. They car kinda feels like a big tank. 327-400 sbc keeps em nice and light.

My thought is to throw a 396 in that car, make a butt load of money off it. Then go buy another one (not 396 car) and throw a punched out 400 in it!

Only other thing that I would suggest doing is to throw a 427 in that car if you dont care about origional or the money you could make off it.

dallam1 10-01-2002 10:06 AM

You got me thinking, I know thinking is dangerous but I put a 455 in my G-body Cutty and the only way I can describe the steering is that it's, well, sluggish! My wife really hates to drive it so I get to put 5 kids in my 455 Cutty and shuffle them back and forth to school. I figure that the 455 is about 80 pounds give or take heavier that the origional motor. My Question is, can I do anything such as putting in real stiff springs in the front etc? How about a little different front end allignment? One thing though, those yellow school busses sure play hell trying to get around me and my 5 little screamers!

NAIRB 10-01-2002 10:17 AM

You should just weigh the differences in the two different engines.
You have to give a big weight savings advantage to the 400 small block, and also remember that parts will be quite a bit cheaper for the small block also.
The 396 is heavier duty, and will make more horsepower due to it's superior breathing ability, and it also lends itself to more cubic inches if you want to stroke it, or bore it more, where you are limited with your 400.
And, as several have mentioned, the originality of your car, but that is just a personal preference, that you must decide. You have to make yourself happy, not everyone else.

ceevu 10-01-2002 10:58 AM

Hello from finland... i saw a comparision between sb400 vs bb402 in chevy hi perf a while ago(built whit similar parts) . BB did
produce more hp but LESS torque! It was those big heads and relatively smal engine. personnally i like that 400 sb.Its pretty light so car handels well and it produses almost enugh power...

RedRocket 10-01-2002 01:26 PM

just something to keep in mind: for certain years of production, the 396 and 427 block were of the same casting - ie. a 396 could possibly be bored out to 427. i'm sure with a little research you could find out if this applies to your block. anybody have any experience doing this?

dallam1 10-01-2002 02:48 PM

Yes, I had an experience boring out a 402 block. I got a "deal" on some 12 to one 427 pistons. This was in about 1977 so I can't remember all of the details but the block had to be bored about 125 thousands. I was with my first wife then and didn't have much money hence the "cobbled together" big block with cheap used (forged) pistons. That motor lasted all of one week before it started belching large amounts of white smoke out of one of the exhausts. There was a huge crack in one of the cylinders! I tore the motor down and had a sleeve installed in that cracked cylinder. The motor ran fine for about a month until I noticed low oil pressure upon acceleration. I was running a stock pan and I'm pretty sure I sucked the pan dry because it wasen't long after the low oil pressure thing that it a main bearing spun. I went back to that same machine shop and the owner got me a "rebuilt steel crank kit" for a 100 bucks. After installiation of the rebuilt crank the motor ran great for a long time but I really hated that high compression. I never could keep it from pinging on hard accelleration. I've never had a big block since then and have enjoyed several trouble free small blocks and am now running a cheap home built 383 in my 4 speed Camaro. I must say that if you're on a strict budget like me then the small block is the way to go. Heck, that big block caused my first wife to leave me. Well, it could have been the womenizing, drinking and coming home very late that made her leave. No it was the big block!

roys63 10-01-2002 02:53 PM

Stay with the big boy


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