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Old 10-16-2004, 01:53 PM   #16
SamBlob
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Re: Definition of big block vs. small block

And then, of course, there's Mopar, with:
A and LA (small block) engines: 273, 318, 340, 360;
B (big block) engines: 350, 383, 400; and
RB (bigger block) engines: 413, 426, 440.
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Old 10-16-2004, 05:10 PM   #17
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Re: Definition of big block vs. small block

Mopar small and big block Engines (revised) Source: www.allpar.com

A ("Early A", Small Block, 1656-1966): 277, 301, 303, 313, 318, 326 (Dodge only):

LA ("Late A", Small Block, 1964-present): 3.9 (V-6, actually a 318 with 2 less cylinders), 273, 318 (Including the 5.2 "Magnum Engine", 340, 360 (Including the 5.9 Magnum Engine), and the 488 & 505 V-10 Engines derived from the LA Design;

B ("Low Block", Big Block, 1958-1978): 350, 361, 383, 400;

RB ("High Block" or "Raised Block", Big Block, 1960-1978): 383 (Smaller bore and longer stroke than the B Engine), 413 (Standard and Max Wedge), 426 (Max Wedge and Hemi), 440.
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Old 10-18-2004, 01:44 PM   #18
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Re: Definition of big block vs. small block

Yup, a real bag of worms! As an engine builder, I can tell you, there are as many descriptions of big and small blocks as there are people describibg them.
The Ford blocks are more of a source of confusion than any other of the American V8s. As previously stated, 221, 255, 260, 289, and 302 are "small blocks". So is 351W, with a taller deck and larger mains. But there are those that use the bellhousing pattern as a determining factor with the Fords. That being the case, 351C is also a small block, as it shares the bell housing flange with the others. 351M (Midland) and 400 share the same pattern with Lima (370, 429, 460). So, are they big blocks? Nope. Modified blocks. At least, that's what we call them in the "industry". FE is the "original" big block Ford, with the 390 being the banner carrier (they made about 8 390s for each of the other CID). There was a 330, 332, 352, 360, 361, 383, 390, 391, 406, 410, 427 and 428. (man, what a list, and I probably missed a couple!) Bullit proof engines. Very inefficient when it comes to fuel vs. power.
The Pontiac is perhaps the biggest anomoly of all, having CID anywhere from 287 to 455, all with the same basic "block". As noted earlier, there are variations in bearing diameter and bore diameter, but all the main parameters are the same. Please, don't use "301" and "Pontiac" in the same sentence... And don't forget the 265!
Suffice it to say, an engine "family" shares bore centers, cam-to-crank centers, cylinder head patterns, etc.
One last thing. You will note the Fords are all named after cities. Those cities are where the foundries are that produced that particular engine family. All but Windsor are in Ohio, and Windsor is in Ontario, Canada.
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Old 10-18-2004, 07:07 PM   #19
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Re: Re: Definition of big block vs. small block

Quote:
Originally Posted by MrPbody
One last thing. You will note the Fords are all named after cities. Those cities are where the foundries are that produced that particular engine family. All but Windsor are in Ohio, and Windsor is in Ontario, Canada.
So the 1.6 litre OHV "Kent" engines are named for Kent, Ohio (home of the infamous Kent State University) and not Kent, England? O.K., I guess I learn something new every day...

What about the "Cologne" V-6s?
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Old 10-19-2004, 03:37 AM   #20
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Re: Definition of big block vs. small block

In general, it can all be narrowed down to some generalizations. Engines like the Pontiac, older Cadillac, and some others don't really have big and small blocks. Every Pontiac engine from the 301 up to the 455 share external dimensions. Things like heads, exhaust manifolds, accessory bolt holes, intakes, and cams all interchange. There are subtle differences like main bearing journal sizes and rod bearing sizes that differ in some families, but they are the same "configuration."

Engines like the Olds are much like the Pontiac. All engines share almost all parameters. The difference is that the "small" block has smaller journals and a shorter deck. The only thing differentiating a small block from big block is deck height and main/rod diameters. Small and big block heads interchange, however don't always work well with in those combinations for compression/port size reasons.

Where I consider the true differentiation is with engines like the Chevy and Ford V8. A chevy small block is a completely different "clean slate" design compared to the big block. A BBC has no more in common with an SBC than it does with a Buick 455. Similarities occured, but mostly for the sake of making it easy at GM to offer both engines in one chassis. Little things like alternators, A/C compressors, and sometimes pulleys and hoses were the same, but otherwise, they are black and white. Ford is very similar, although as somone pointed out, the line is blurred. The most common small block is the Windsor, so its considered the "Ford small block" in many situations. The 289, 302 and 351W are nearly as interchangeable as a chevy's 283, 305, 350, and 400 are to each other.
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Old 10-19-2004, 08:01 AM   #21
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Re: Definition of big block vs. small block

The names of the FORD V8s was my only point, when engine families have "names". Anyone know where FE, Ohio is? Gimme a break...
The 265/301 Pontiac "baby block" shares only bore spacing and main journal diameter. Virtually nothing else fits the "real" Pontiacs.
The 400, 425 and 455 Olds are similar to the small blocks, but have a MUCH higher deck and longer connecting rods. They could be considered remotely similar, but they are definitely called "big" and "small" block... Same is true of the Buick.
Although very similar in design, and just a bit bigger, very little of what fits the little Fords, fit the 351W. Heads, some of the gaskets, that's about it. And even the heads need modification to fit. You could say the cam/lifter does, but there are differences between early and late.
The purpose of this posting is not to dispute anyone's statements, but to clariify what does and does not fit between engines. If you've ever had a customer crying the blues because they "heard" all the parts were the same between a 327 and a 350, only to find the 327 crank WON'T fit in the 350 block, you will appreciate it.
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Old 10-21-2004, 08:32 PM   #22
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TOTALLY NEWBISH DUMB QUESTIONS:

What is a block?

What is a good place to learn all this terminology?
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Old 10-22-2004, 09:49 PM   #23
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Re: Definition of big block vs. small block

Quote:
Originally Posted by stefanzhr
TOTALLY NEWBISH DUMB QUESTIONS:
Here we have one who loves truth. This is generally a good thing.

Quote:
Originally Posted by stefanzhr
What is a block?
It's the part of the engine between the crankcase and the head. The crankshaft is held in bearings that are mounted in the crankcase, just about where it meets the block. Most engines (I think) are "wet sump" engines, which means that the engine oil is stored in a tank at the bottom of the crankcase. The block is usually one casting made up of cylinders, cooling jackets (or fins on Corvairs, old VWs, and other air-cooled cars...) and mounts for sensors, hoses, pulleys and other $#!+ like that. Engine blocks on musclecars also have bearings in them in which the camshaft is mounted; some newer American cars and most non-American cars have the camshaft(s) in the head, where the valves, combustion chambers and manifold mounts are.

Quote:
Originally Posted by stefanzhr
What is a good place to learn all this terminology?
Look in a search engine for "Glossary of Automotive Terminology". Or ask a mechanic, preferably one with good manners and lots of patience.
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Old 10-22-2004, 10:11 PM   #24
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Re: Definition of big block vs. small block

I think we all forgot to mention the Buick Special 215 alloy-block V-8 from the early '60s...

Sadly, the only survivor in passenger use is the Small-Block Chevy. Ford, Cadillac, Dodge and Chrysler all use more recent V-8 designs with no link to the classic designs. Buick and Pontiac no longer have V-8s of their own, although the small-block Buick lives on in part in (and maybe in parts of...) the Buick 3800 V-6. Oldsmobile does not even exist anymore, much less have a V-8 of its own. The Rover Group no longer makes the Rover 3500 (formerly Buick Special 215). Sad, sad situation.
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Old 10-23-2004, 10:41 AM   #25
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Re: Definition of big block vs. small block

Stefanzr, you can find a bit of what you're after, on our website. I've written a "glossary of terms" and put it out there. It may not answer ALL your questions, but it will certainly hit a few!

centralvirginiamachine.com
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Old 10-23-2004, 10:51 PM   #26
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Thanks SamBlob and MrPbody.

MrPbody, the url doesnt work.
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Old 10-25-2004, 08:20 AM   #27
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Re: Definition of big block vs. small block

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Old 01-08-2006, 04:11 PM   #28
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Re: Definition of big block vs. small block

Quote:
Originally Posted by Musclecarclub
I have never seen a really good explanation for the difference between a small block and a big block. I mean, obviously a big block is bigger, but what is the dividing factor? What was/is the largest small block and smallest big block? Any ideas?

For American Motors V8 cars starting with 1967. The design of the AMC engine is a small block. Based on the physical size and the deck. 290, 304, 343, 360, 390 and 401 are all from the same block. You can not tell from looking at an AMC block what cubic inches it is. The only way to tell is a casting number on the side of the block. NONE of these engines are from, Ford or Mopar! as many people think. These are 100% AMC made in USA. So, from my point of view.. it is not based on cubic inches, rather it is based on the mass, physical size and deck.
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Old 01-09-2006, 12:02 PM   #29
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Re: Definition of big block vs. small block

Woody,

You dragged up an old one! It's okay. This subject has been debated in another thread, as well.
Your assertions about the Rambler are correct. All the external dimensions for the various CIDs are the same. So, like the Pontiac, there is no "big block" or "small block" AMC, there's simply the "Rambler" (in the shop vernacular...).

Jim
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Old 01-12-2006, 12:26 AM   #30
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Re: Definition of big block vs. small block

The same kinda question could be asked if any of AMC's cars were muscle cars because of the 2 seater. Only AMC had the only entry 2 seat muscle car.

Sorry Vette and Viper guys , you have sport cars, not muscle cars.

Or did AMC want it's car to run with sports cars, or was it more of a Pony car?
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