at what ci does a block become "big"

  • Sponsors(?)


RangerJoe

I leave the horn on while driving
5 Year Member
Apr 26, 2010
2,666
1,232
174
Georgia
You lost me.... Are you asking what cubic inches came in a big block?

Joe
 

gearheadboy

15 Year Member
Jan 15, 2003
1,440
184
84
46
Greencastle Pa
always wondered
With all due respect.....LMAO! Now that I have that off my chest, some car manufacturers produced engines of different configurations. Some were smaller blocks than others. Cubic inch really had nothing to do with it. For instance a 351w may be considered a small block, whereas a 351c or 351m may be considered big blocks or mid blocks. Generally speaking engines configured from most manufacturers having large cubic inches are big blocks because its hard to fit 460 cubic inches in a reliable small package. I'm sure you'll get different stories here but this is a general explanation.
 

HuskerNation

Member
Nov 4, 2011
252
16
19
West Des Moines, IA/Omaha, NE
So a 396, 366, 350, etc are not big blocks I guess.
A 350 is a small block. SBC. Thats why you will hear terms that some mustangs have a SBC 383 stroker.

It all depends on manufacturer and this question is one that has way too many different views for one to be absolutely correct. This is what Chevy considers on how theirs are rated. They don't base a SBC or BBC off of CI, but they base it off of displacement.

Small Block: The smaller of a manufacturers two series of engines. In the case of Chevy, the small block includes the 262, 265, 267, 283, 302, 305, 307, 327, 350, and 400.

Big Block: The larger of a manufacturers two series of engines. In the case of Chevy, the 366, 396, 402, 427, and 454.
 

gearheadboy

15 Year Member
Jan 15, 2003
1,440
184
84
46
Greencastle Pa
A 350 is a small block. SBC. Thats why you will hear terms that some mustangs have a SBC 383 stroker.
Like I stated originally, there will be many opinions. Having worked at a dealer that sold Pontiacs which could be equipped with either a 350 Pontiac (which the literature termed the BIG block at that time) or a 350 Chevrolet which was referred to as a small block, I'll have to beg to differ with you.
 
  • Like
Reactions: 88LX5.Oh

MikeySmikey

New Member
Dec 6, 2012
20
0
2
37
Missouri
Generally it has to do with bore and stroke. Most small blocks (with some exceptions) have a 4 in. bore and 3.5 in. stroke. Most big blocks have a 4.25 in. bore and 4 in. stroke. Granted this isn't always the case but it's what I've found most of the time. As I said, there are exceptions. The Chevy small block 400 has a 4.125 in. bore and 3.75 in. stroke. The biggest difference is the length of the rods. Most small blocks use a 5.7 in. rod, where as big blocks use a 6.13 in. rod. Using simple logic, what makes an engine a small or big block is the length of the cylinder itself and the stroke of the rod & piston.
 

gearheadboy

15 Year Member
Jan 15, 2003
1,440
184
84
46
Greencastle Pa
Generally it has to do with bore and stroke. Most small blocks (with some exceptions) have a 4 in. bore and 3.5 in. stroke. Most big blocks have a 4.25 in. bore and 4 in. stroke. Granted this isn't always the case but it's what I've found most of the time. As I said, there are exceptions. The Chevy small block 400 has a 4.125 in. bore and 3.75 in. stroke. The biggest difference is the length of the rods. Most small blocks use a 5.7 in. rod, where as big blocks use a 6.13 in. rod. Using simple logic, what makes an engine a small or big block is the length of the cylinder itself and the stroke of the rod & piston.
Once again, that has 0 to do with big block or small block. And if every small block had a 3.5" stroke and a 4" bore, they would all be 350's. Well, depending on the rod.
 

srtthis

the guy doing it does every local racers rear end
10 Year Member
Jul 3, 2009
5,006
1,548
194
Maryland
www.crazybobracing.com
A 350 is a small block. SBC. Thats why you will hear terms that some mustangs have a SBC 383 stroker.

It all depends on manufacturer and this question is one that has way too many different views for one to be absolutely correct. This is what Chevy considers on how theirs are rated. They don't base a SBC or BBC off of CI, but they base it off of displacement.

Small Block: The smaller of a manufacturers two series of engines. In the case of Chevy, the small block includes the 262, 265, 267, 283, 302, 305, 307, 327, 350, and 400.

Big Block: The larger of a manufacturers two series of engines. In the case of Chevy, the 366, 396, 402, 427, and 454.
They made a 350 big block also
 

srtthis

the guy doing it does every local racers rear end
10 Year Member
Jul 3, 2009
5,006
1,548
194
Maryland
www.crazybobracing.com
The way they word big block vs small block in the 275 rules is...

Big block Chevy short deck is 9.8" deck height
Big block Chevy tall deck is 10.2"
Big block ford is 10.3" deck height
Big block mopar is a 10.6" deck height.

Small blocks are anything less then that with a stock bore space for GM ford or mopar.
 

gearheadboy

15 Year Member
Jan 15, 2003
1,440
184
84
46
Greencastle Pa
A 350 is a small block. SBC. Thats why you will hear terms that some mustangs have a SBC 383 stroker.

It all depends on manufacturer and this question is one that has way too many different views for one to be absolutely correct. This is what Chevy considers on how theirs are rated. They don't base a SBC or BBC off of CI, but they base it off of displacement.

Small Block: The smaller of a manufacturers two series of engines. In the case of Chevy, the small block includes the 262, 265, 267, 283, 302, 305, 307, 327, 350, and 400.

Big Block: The larger of a manufacturers two series of engines. In the case of Chevy, the 366, 396, 402, 427, and 454.
"They don't base a SBC or BBC off of CI, but they base it off of displacement." WHAT? REALLY? cid= Cubic inch displacement. Its the same thing.
 

MikeySmikey

New Member
Dec 6, 2012
20
0
2
37
Missouri
Once again, that has 0 to do with big block or small block. And if every small block had a 3.5" stroke and a 4" bore, they would all be 350's. Well, depending on the rod.
So basically you're saying that the info I gave is entirely incorrect. Did you miss the part where I said there are exceptions, because I'm pretty sure I did, and also said that it was most not every.
 

gearheadboy

15 Year Member
Jan 15, 2003
1,440
184
84
46
Greencastle Pa
So basically you're saying that the info I gave is entirely incorrect. Did you miss the part where I said there are exceptions, because I'm pretty sure I did, and also said that it was most not every.
Its not that its entirely wrong. The point is you can't specify that a certain stroke or bore has anything to do with being designated a big or small block. You also stated that MOST but not all small blocks have a 3.5" stroke with a 4" bore. That is totally incorrect. If most DID then they would be 350's, well depending on the rod variable. The stroke and bore can be anything that will work within the limits of the casting. Thus you can have a .030 over 302, .040 over 302 etc. and any small block can be stroked or de-stroked. Any of these variables will never make it a big block. Also a big block could use different rods and crank, offset grind etc to become a 200 cid engine but would still be a big block.
 

MikeySmikey

New Member
Dec 6, 2012
20
0
2
37
Missouri
Its not that its entirely wrong. The point is you can't specify that a certain stroke or bore has anything to do with being designated a big or small block. You also stated that MOST but not all small blocks have a 3.5" stroke with a 4" bore. That is totally incorrect. If most DID then they would be 350's, well depending on the rod variable. The stroke and bore can be anything that will work within the limits of the casting. Thus you can have a .030 over 302, .040 over 302 etc. and any small block can be stroked or de-stroked. Any of these variables will never make it a big block. Also a big block could use different rods and crank, offset grind etc to become a 200 cid engine but would still be a big block.
You raise plenty of valid points, all of which are correct. And in that sense so did I. I simply wanted to lay the basis for the differences.
 

88LX5.Oh

5 Year Member
Dec 30, 2011
1,445
207
84
Arkansas
As Gearhead has already stated, cubic inches has absolutely nothing to do with "big" or "small" blocks. Look at the FE 352. It is considered by most a big block yet is only 1 cubic inch larger than a 351 Windsor.

Well ACTUALLY if you want to get technical, the 351W has the SAME cubic inches as the FE 352 since both share 4" bore and 3.5" stroke. Both the 352 and 351 are truly 351 cubic inches but Ford rounded up with the FE block because most companies did that, like a GM 350 isn't a true 350, it's 349. But Ford wanted to differentiate the Windsor apart from the FE block so it wouldn't confuse people. Why think Ford called the 302 a 5.0 when in all reality it's a 4.9? Because they didn't want people to think they had a straight six in their GT Mustangs.


But to be back on topic, I don't really use block size or BS like that to classify their engines. I use "Series" to identify their engines. Windsor series, FE series, 335 series, and 385 series. If I were to see a 390, I would call it an FE but most call them big blocks. To each their own.
 
  • Like
Reactions: FordRacing302
Thread starter Similar threads Forum Replies Date
modulistic When Purchasing Heads, Does Year Of The Block/car Make A Difference. Fox 5.0 Mustang Tech 6
streetyme does the new 302 boss block use canted heads? Fox 5.0 Mustang Tech 9
2000fordstanggt does this block heater fit? SN95 4.6L Mustang Tech 6
ADRENLN what does a built short block weigh? 1996 - 2004 SN95 Mustang -General/Talk- 14
B How much does it cost you to prep a block? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 2
'13_ImpactBlue_GT Does my GT have a Romeo or Windsor block? SN95 4.6L Mustang Tech 22
OrangeMustangGt Why does the block split at high hp? 1994 - 1995 Specific Tech 12
BlueOvalStangGT Looking for a new block that can handle +550 easily. Does this make sense? 1994 - 1995 Specific Tech 4
StreetDreamsGT Does this block look like crap? Fox 5.0 Mustang Tech 20
S how much does a 302 block and heads weigh Fox 5.0 Mustang Tech 10
8 Does 331 stroker block need notching Fox 5.0 Mustang Tech 12
C New DSS 331 block - Does everything else bolt on? 1994 - 1995 Specific Tech 9
S Cracked my block! Where can I find an affordable block? New or Used, does it matter? 1994 - 1995 Specific Tech 1
S Does any one have pictures of a 347 block. Fox 5.0 Mustang Tech 1
silverlx50 Engine Does anyone have a picture of the O2 sensor harness orange ground wire? Fox 5.0 Mustang Tech 3
R 1995 Mustang power window does not work. 1996 - 2004 SN95 Mustang -General/Talk- 0
79pace 82GT Does not Crank the Starter with the Key 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 4
S vehicle shut of and does not want to start up again 2005 - 2009 Specific Tech 0
F Electrical Does EFI computer case need to grounded? Fox 5.0 Mustang Tech 22
Habu135 Fox : How Much Power Does a Stock 1993 Cobra Make? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 7
S Does Having a dead battery make the PCM fail? 2005 - 2014 S-197 Mustang -General/Talk- 0
M Brakes Does anyone know specific casting numbers on 1989 GT O.E. Calipers? Fox 5.0 Mustang Tech 11
G One coilpack not getting spark but does have power at wire SN95 4.6L Mustang Tech 3
C Does a 2015 Mustang have a radio code? 2015+ Specific Tech 0
J Does anyone know where this wire goes? Other Auto Tech 28
kiddiccarus Does anyone customize the interior of the 94-95? I am running into brick walls 1996 - 2004 SN95 Mustang -General/Talk- 0
T Need good/affordable cooling fan for Mach 1 that does not vibrate too much 1996 - 2004 SN95 Mustang -General/Talk- 3
S Where does this negative cable go??? 2005 - 2009 Specific Tech 3
9 What does the coil pack Capacitor do ? 1996 - 2004 SN95 Mustang -General/Talk- 3
Z Newbie question, Backup lights on 65. Does 12v for lights go thru neutral switch? 1965 - 1973 Classic Mustangs -General/Talk- 1
C Does she have a nice rear end or what? 1965 - 1973 Classic Mustangs -General/Talk- 10
ndfox92 Fox does anyone have a victor efi intake for a 351w they want to part with? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 0
MrPerfect2 What does the idle sound like if timing is 14 vs 12 degrees 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 18
J 94 GT Convertible. What does this harness connect to? 1994 - 1995 Specific Tech 0
J Paint and Body Does my floorpan need replacing? Fox 5.0 Mustang Tech 8
A Does it make sence ? 2005 - 2014 S-197 Mustang -General/Talk- 1
90sickfox Does any one else wish the 18 amd 19 fog lights were lower ??? 2015+ (S550) Mustang -General/Talk 0
M Does anyone know what the hole to the left of the oil pressure sender is for?? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 6
J Does Ford Performance make 3.73 gear for v6 mustangs? 2005 - 2014 S-197 Mustang -General/Talk- 8
MrPerfect2 Engine 1991 - What does a normal idle suppose to sound like on OEM 5.0 ? Fox 5.0 Mustang Tech 7
horse sence Shaker assembly ,what year does it fit? 2005 - 2014 S-197 Mustang -General/Talk- 3
79 Fox Fox Burning oil... Does my theory make sense? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 9
79 Fox Fox Does this make sense? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 6
D Engine Does this look like TDC? (SOLVED) Fox 5.0 Mustang Tech 2
Blucifer99 Does anyone kno the deadtimes and voltage offset for these injectors Digital Self-tuning Forum 0
K Does Orange Dexcool Turn Red/Pinkish? S550 Mustang 2015+ (S550) Mustang -General/Talk 0
billison Does anyone else have one of these. 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 15
BlakeusMaximus Where does antenna wire disconnect? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 1
B Does the coolant tank on this 4l v6 look ok? 2005 - 2014 S-197 Mustang -General/Talk- 0
Similar threads