What's a small block

[FleetsidePaul]

I know it seems like a stupid question, but a buddy of mine offered to give me a free 400 C.I. "small block". I was planning on putting in a 350 mostly because there is no other engine that parts are more available for. I mean really, what's easier to find parts for. but can I use 350 parts on a 400, if they are both small blocks, It would be great to get a free motor, but if it is going to be a problem getting parts, then i want to know. It was pulled from a running truck, so it runs but it need to be rebuilt. Is it worth haulin home and going through ???? I would of asked my friend, but I didn't want to seem like an ingrate.

[stllookn]

You're right...I will take the small block 400!!!!!!! Actually the small block 400 is very similar to and uses all the same parts as a 350 except the block, crank and external balancer. If you put a 400 crank in your 350 you end up with a 383. Take it...that motor rocks...DUDE and has more torque and hp than a 350. Just tell everyone it's just a 350 after you smoke'm.

[68C15]

or.......put the 327 crank in the 400 after you bore it out .040. then you will have a 351 with a VERY high rev limit. I know a guy who has one with roller cam bearings (yes, I said bearings) & his power band starts about 6000.

for future reference here is the displacements offered in small block form from GM.
262, 265, 267, 283, 327, 350, 400. parts from all will interchange except for valve covers from pre 1957. the early ones have a little different bolt pattern. pre 1968 (I think) crankshafts have a smaller main bearing journal. after that they went to a 2.10 main journal. the 400 has "steam" holes drilled in the heads and block between the middle cylinders.

in short I would take it. after all its free!!

[Tx Firefighter]

68C15, you forgot a few....

it's 262, 265, 267, 283, 302, 305, 307, 327, 350, and 400.

There are 10 different displacement sizes of small block Chevys.

[GloryHound]

Also you have to remember you can change displacement by swapping crank's or over boring the cylinders. Some popular numbers are the 335, 355, 377, and 383, but this is not an all inclusive list the posibilities are almost endless with the Small block chevy. Also using after market blocks I believe they are up to a reliable 427 CID small block chevy engine and if reliability is not the issue you can even go a little higher. This is what I love about the Small Block Chevy. The Big Blocks have pretty much the same interchangeability and again lots of different numbers can be produced. The 400 block is an excellent base. If you plan on building an engine that goes over 500 HP you may want to change it to a 4-bolt main and add the extra external cooling system plumbing that runs between the block and heads. Other wise 400 sbc engines are great since it is cheaper and easier to build an engine that has horsepower numbers less than or equal to its Cubic Inches, but once you start asking for more horsepower than you have Cubic Inches it starts to get expensive with a lot more research required.

[panhandler62]

What's funny is that we always call the 400 a "400 small block" as if the distinction was required.

There is no, despite some Chevrolet badging that argues differently, 400 big block. The closest chevy engine is the 396. Anything labeled "400" with a big block is actually an Oldsmobile or Buick. (Oldsmobile and Buick actauly *do* have small and big block 400s)

[tnblazerk5]

Originally Posted by panhandler62

What's funny is that we always call the 400 a "400 small block" as if the distinction was required.

There is no, despite some Chevrolet badging that argues differently, 400 big block. The closest chevy engine is the 396. Anything labeled "400" with a big block is actually an Oldsmobile or Buick. (Oldsmobile and Buick actauly *do* have small and big block 400s)

you forgot a about the big block 366 although they didnt come in cars , just big trucks

[special-K]

The 400 emblem on trucks denotes the 402 big block.Once displacement was increased,SS396s were actually 402s.
The factory 400 small block can be built to 406 and 426 with some cutting.

[Frizzle Fry]

Originally Posted by panhandler62

What's funny is that we always call the 400 a "400 small block" as if the distinction was required.

There is no, despite some Chevrolet badging that argues differently, 400 big block. The closest chevy engine is the 396. Anything labeled "400" with a big block is actually an Oldsmobile or Buick. (Oldsmobile and Buick actauly *do* have small and big block 400s)

Wouldn't the closest thing to a 400 BBC be a 402?

[tomatocity]

Originally Posted by Tx Firefighter

68C15, you forgot a few...
it's 262, 265, 267, 283, 302, 305, 307, 327, 350, and 400.
There are 10 different displacement sizes of small block Chevys.

I am not familiar with the 262 and 267 though I have heard these mentioned on this board. The 262 I am familiar with is the 4.3L V6. 267?

[panhandler62]

Originally Posted by Frizzle Fry

Wouldn't the closest thing to a 400 BBC be a 402?

By displacement, yes, but the 396 and 402 are actually the same engine.

[panhandler62]

I am not familiar with the 262 and 267 though I have heard these mentioned on this board. The 262 I am familiar with is the 4.3L V6. 267?

Here is a good reference.
http://en.wikipedia.org/wiki/Chevrolet_V8_engine

There was a 4.3l in 1075 (262) , the 4.4l (267) was used in 1979 in A body cars.

I hadn't known about these either. I had thought all of the rinky-dink v8s were variants of the 305 until the new engine family came out in the 90s.

[FleetsidePaul]

Well it looks like I'll have to clear some space in the garage.. Thanks for the info. I must be livin right or something.

[MandarinSixSeven]

Originally Posted by panhandler62

Here is a good reference.
http://en.wikipedia.org/wiki/Chevrolet_V8_engine

There was a 4.3l in 1075 (262) , the 4.4l (267) was used in 1979 in A body cars.

I hadn't known about these either. I had thought all of the rinky-dink v8s were variants of the 305 until the new engine family came out in the 90s.

I have a 267 V8 in my 81 Monte Carlo. Man, talk about a piece of...came stock with 110hp! woo-hoo

[pissonNOS]

so a 396 is a small block for some weird reason i always thought it was a big block i dunno y

[acloco]

The 400 tag on big blocks intended to obscure for insurance reasons in the early 70's. By that time, ALL of the insurance companies knew wht 426, 427, 440, & 454 meant.

I have never heard why GM built 396 engines that were actually 402 cubes.....we may never know.

[GloryHound]

They were trying to make up for the initial horse power loses due to the change from closed cumbustion chambers to open cumbustion chambers by adding hidden Cubic Inches with the least amount of design change as possible. Radical design changes cost big bucks. It was later determined that the open combustion chamber could produce more horse power, but they did not have time to do the initial research due to the emmision changes. The big question is why did they get rid of the "W" heads that the 348 and 409 used?

[68C15]

chevy made two 262 engines. the first was a V8 while the second was a V6. the V6 was basically a 305 with two of the middle cylinders left out. it makes for a real shaker. that's why it has a balance shaft in the later versions.

[acloco]

gloryhound...the W head question is easy....LOTS better flow with the individual ports and taller head (overall) of the "porcupine" heads.

[3 on the tree]

Originally Posted by GloryHound

They were trying to make up for the initial horse power loses due to the change from closed cumbustion chambers to open cumbustion chambers by adding hidden Cubic Inches with the least amount of design change as possible. Radical design changes cost big bucks. It was later determined that the open combustion chamber could produce more horse power, but they did not have time to do the initial research due to the emmision changes. The big question is why did they get rid of the "W" heads that the 348 and 409 used?

W motors were expensive to build and heavy. If I remember correctly, the heads had almost no combustion chamber, it was in mthe top of the pistons, so they were very heavyfor their bore size.

[panhandler62]

Originally Posted by MandarinSixSeven

I have a 267 V8 in my 81 Monte Carlo. Man, talk about a piece of...came stock with 110hp! woo-hoo

I hear you... I test drove a Corolla tonight that has more power than that in an engine about the size of a sewing machine. lol (Hey -- take it easy.. if you drove 63 miles to work, one way, you wold want at lest one econo car too! lol)

Originally Posted by pissonNOS

so a 396 is a small block for some weird reason i always thought it was a big block i dunno y

The 396/402 *is* a big block. The 400 and 383 (which GM never made, but 9 million rodders have!) are small blocks, unless you have a Mopar. Then the 383 is a low deck big block ( as opposed to a high deck big block) ... Hey.. don't ask me! Mopar motors make nice power, but I hate the complete lack of interchangeability.

I grew up on bowties and was shocked to learn that you couldn't just snatch the heads off of a 340 and stick them on a 318.

[GasHog396]

Have the 400 SBC block checked out before getting any parts (pistons, rings, etc.), 0.030 to 0.040 is about the safest overbore you can go if you plan on any performance upgrades in the future. If it is to remain bone stock, you may get a 0.060 overbore. There are 400's out there running a 0.060 overbore, but there a lot more that are boat anchors after the cylinder walls cracked. 400 blocks have what they call siemesed cylinder walls to strenghen the area between the cylinders, which basically means there is less metal between the cylinders, so max overbores typical on a 350 are out. 400's are more expensive to rebuild than the 350, but the added torque is worth the money. In addition, both the harmonic balancer and the flexplate (auto trans) is unique to the SBC 400, as the engine, from the factory, is externally balanced, as opposed to all other factory SBC's, which are internally balanced.

400 heads also have 'steam' holes in them. I've heard you can use 350 heads and drill out the holes using a 400 head gasket as a template. I've heard conflicting information on the necessity of the steam holes, but I guess if Chevy didn't think they were necessary, they wouldn't have put them there in the first place. These are great engines, and in stock form, don't rev up like a 350, but the increased torque is seat of the pants fun. At the worst, if the block is toast, you still have the crank to turn down to make a 383.

[tomatocity]

Originally Posted by acloco

I have never heard why GM built 396 engines that were actually 402 cubes.....we may never know.

I heard that GM was supposed to not manufacturer anything over 400 c.i. so they badged the 402 truck engines as a 400. Whats 2 cubic inches amongst friends. I don't know this to be factual though it is solid shop talk.

[panhandler62]

Originally Posted by tomatocity

I heard that GM was supposed to not manufacturer anything over 400 c.i. so they badged the 402 truck engines as a 400.

The 427 was introduced in 67 and the 454 in 70 so I think that was probably just an urban legend. The 400 badge probably has more to do with marketing than anything else.

My favorite is slightly obscure.. lol

The largest V8 engine to date appeared in 1968 when Cadillac unveiled their 472 in³ version. This huge engine delivered 375 hp (280 kW) but specialized in torque, with 525 ft.lbf (712 Nm) produced at just 3000 RPM. The power rating was conservative, however, as the engine could produce at least 420 hp (313 kW) in the real world.

http://en.wikipedia.org/wiki/Cadillac_V8_engine

[Longhorn Man]

There are many stories on why the 396 gre 30 over into a 402, some are purely stupid, and others kinda make some sence. The one i tend to believe, Chevy did not want a small block to be bigger than there small big block. So, when the 400 small block was introduced in 1970, they bumped up the cubes on there baby big block.

Why play with a 472 when a 500 is there for the pickin?

500In 1970, Cadillac introduced the largest modern V8, the 500 in³ (8.2 L) Eldorado motor. It was rated at 400 hp (298 kW), but could in actuality produce 435 hp (324 kW) or more. But the emissions and economy restrictions of the 1970s (as well as the switch from gross to net ratings) dropped output to 235 hp (175 kW) (for the Eldorado) and 220 hp (164 kW) (for the rest) in 1971.