What makes an engine a 'big block'?

topgun1 · 07-25-2010, 11:02 AM

I've always wondered this. Is there a certain cut-off in engine displacement where a motor is considered a 'small block' and above a certain size a 'big block'? or is it other factors? curious

Apex Paul · 07-25-2010, 11:09 AM

It is not really about engine displacement, it is more accurately a distinction made by bore separation. For example, a Z06 Corvette with a 7 liter 427 CID engine is a small block, while a Chevelle SS with a 396 CID is a big block. As you can see, that wouldn't make any sense if CID were the determining factor for calling it big/small.

superstockcam · 07-25-2010, 11:15 AM

Heavier but much stronger,displacement up to 572 cid. larger free flowing heads and all sorts of other advantages in running a big block, now though the all aluminum motors are better IMO.

spyderbuddy · 07-25-2010, 11:24 AM

don't know about ford or dodge but,
mouse motors
small block chevy was 262, 265, 283, 302, 305, 327, 350 & 400 cuin
these engines bacically use the same block, they just diff bore and stroke

then you had the w blocks 348 & 409 cuin

rat motors
and then what chevy called big block
396, 402, 427, 454
and then the same block again just bore and stroke

AZCamaroFan · 07-25-2010, 12:57 PM

simply put it's the size of the engine block. A 409 and a 283 were completely different engines, with different size blocks. Same for the 327 and 427. The 454 was the last of the 'big blocks' at Chevrolet. The 427 in the current ZO6 Corvette is actually a 'small block'.

*DGthe3* · 07-25-2010, 02:09 PM

Quote:

Originally Posted by AZCamaroFan

simply put it's the size of the engine block. A 409 and a 283 were completely different engines, with different size blocks. Same for the 327 and 427. The 454 was the last of the 'big blocks' at Chevrolet. The 427 in the current ZO6 Corvette is actually a 'small block'.

Yup, the block in a big block is bigger than the block in a small block. Sounds obvious, but thats the basis for it.

For example, on Chevy's the bore spacing on a small block is 4.4" while its 4.84" for a big block. The deck height is 9" for a small block vs 9.8" to 10.2" on big blocks. These differences don't sound like much but it means the max displacement for a small block is about 7L while a big block can surpass 10L.

2010 SSRS · 07-25-2010, 02:15 PM

Here is my 502 Big Block

Paul Huizenga · 07-25-2010, 02:36 PM

Some engine families never had that distinction - Pontiac corporate engines, for example, were all one block architecture regardless of displacement.

AZCamaroFan · 07-25-2010, 03:22 PM

yes that's true. i didn't realize that for a long time
first time i saw a 396 under a hood i was shocked by the size .

formare · 07-25-2010, 03:28 PM

Quote:

Originally Posted by AZCamaroFan

simply put it's the size of the engine block. A 409 and a 283 were completely different engines, with different size blocks. Same for the 327 and 427. The 454 was the last of the 'big blocks' at Chevrolet. The 427 in the current ZO6 Corvette is actually a 'small block'.

What he said x2... It's the physical size of the casting of of metal (ie e block) that holds the pistons and crank and other stuff..

topgun1 · 07-25-2010, 03:32 PM

Quote:

Originally Posted by 2010 SSRS

Here is my 502 Big Block

NICE!!

topgun1 · 07-25-2010, 03:33 PM

Quote:

Originally Posted by AZCamaroFan

simply put it's the size of the engine block. A 409 and a 283 were completely different engines, with different size blocks. Same for the 327 and 427. The 454 was the last of the 'big blocks' at Chevrolet. The 427 in the current ZO6 Corvette is actually a 'small block'.

I love the 454 engine. If I ever get a 69 chevelle SS, I want that engine in it!

thanks for all the info to all, but still....what are the actual specifications that make a block a "big block"? is it a very blurry line or a fine line--i.e. certain bore and stroke, certain displacement, liter, etc.

Silver2SSRS6spd · 07-25-2010, 03:34 PM

Nothing looks better then a big block in an old Camaro, Vette or Chevelle. The easiest way to tell is by the valve covers.

Silver2SSRS6spd · 07-25-2010, 03:36 PM

Quote:

Originally Posted by Paul Huizenga

Some engine families never had that distinction - Pontiac corporate engines, for example, were all one block architecture regardless of displacement.

Pontiac had small and large journal engines. More info if you check the link below.

http://en.wikipedia.org/wiki/Pontiac_V8_engine

07-25-2010, 11:02 AM	#1
topgun1 Drives: 10 SIM 2SS/RS LS3 Join Date: May 2008 Location: Winston-Salem, NC Posts: 1,939 View My Garage	What makes an engine a 'big block'? I've always wondered this. Is there a certain cut-off in engine displacement where a motor is considered a 'small block' and above a certain size a 'big block'? or is it other factors? curious __________________ 5th Gen Camaros of the Carolinas SIM, 2SS/RS LS3 5/7/11 453.9 RWHP 427.5 RWTQ VMS Stage 2.5 Comp Cams kit, Cold Air Inductions intake, ADM race scoop, DT 1 3/4" headers, Solo cats, 3" Magnaflow catback, Pypes cutouts, HP tune, H&R SuperSport springs, Eibach sways/spacers, TexasSpeed UD pulley, LSR tensioner pulley, Barton shifter, skip shift eliminator, powder-coated calipers, R1 concept rotors, StopTech pads, Granatelli wires, Lloyds mats, tint, AAC afterburner taillamps, AAC scanner/sidemarkers, SRP pedals, custom engine cover, black bowties, Ridergraphix hood spears.... Last edited by topgun1; 07-25-2010 at 03:30 PM.

07-25-2010, 11:09 AM	#2
Apex Paul Drives: Wagon Queen Family Truckster Join Date: Oct 2009 Location: Louisville, Ky Posts: 1,476	It is not really about engine displacement, it is more accurately a distinction made by bore separation. For example, a Z06 Corvette with a 7 liter 427 CID engine is a small block, while a Chevelle SS with a 396 CID is a big block. As you can see, that wouldn't make any sense if CID were the determining factor for calling it big/small. Last edited by Apex Paul; 07-25-2010 at 11:20 AM.

07-25-2010, 11:15 AM	#3
superstockcam Member Drives: 2010 ABM 2SS/RS LS3 Join Date: Feb 2009 Location: Where you vacation...Tahoe Posts: 928	Heavier but much stronger,displacement up to 572 cid. larger free flowing heads and all sorts of other advantages in running a big block, now though the all aluminum motors are better IMO. __________________ .

07-25-2010, 11:24 AM	#4
spyderbuddy Drives: 2010 RS Inferno Orange Metallic Join Date: Mar 2010 Location: Albany, Ga. Posts: 3,474 View My Garage	don't know about ford or dodge but, mouse motors small block chevy was 262, 265, 283, 302, 305, 327, 350 & 400 cuin these engines bacically use the same block, they just diff bore and stroke then you had the w blocks 348 & 409 cuin rat motors and then what chevy called big block 396, 402, 427, 454 and then the same block again just bore and stroke __________________ 2024 Camaro/Panther Emblem,Hot Wheels Emblems, Hot Wheels Door Sills and Floor Mats, Morimoto Fog Lights, PCP Hideaway Headlight Covers, BBK Headers & High Flow Cats, ZL1 Add-ons Wicker Bill, TL1/ZL1 Hood Insert, Gen5 DIY Frameless Mirror, ABL Dash Lighting & My link Navigation, Blacked out Rear Bowtie, all Sylvania led Turn Signals, Ceramic Window Tint By Nicks, MBRP Exhaust tips, GEN5 DIY Virginia Legal DRL Harness, Painted Brake Calipers, Vittesse Throttle Controller & Paddle Shifter Heritage Grill, Manual Shifter Boot, CNC Throttle Body, Trifecta Tune, Trunk Black out and Side Grills,

07-25-2010, 02:15 PM	#7
2010 SSRS Drives: 3 V8 Camaros Join Date: May 2009 Location: The Ocean State Posts: 111,186 View My Garage	Here is my 502 Big Block __________________ Jannetty Racing JRE Street Package

07-25-2010, 12:57 PM	#5
AZCamaroFan Camaro6 2016-2018 Drives: sometimes Join Date: Mar 2008 Location: Phoenix Posts: 18,468	simply put it's the size of the engine block. A 409 and a 283 were completely different engines, with different size blocks. Same for the 327 and 427. The 454 was the last of the 'big blocks' at Chevrolet. The 427 in the current ZO6 Corvette is actually a 'small block'.

07-25-2010, 02:36 PM	#8
Paul Huizenga Drives: 1991 Syclone, 2000 Corvette Join Date: Jun 2010 Location: San Diego, CA Posts: 114	Some engine families never had that distinction - Pontiac corporate engines, for example, were all one block architecture regardless of displacement.

07-25-2010, 03:22 PM	#9
AZCamaroFan Camaro6 2016-2018 Drives: sometimes Join Date: Mar 2008 Location: Phoenix Posts: 18,468	yes that's true. i didn't realize that for a long time first time i saw a 396 under a hood i was shocked by the size .

07-25-2010, 03:34 PM	#13
Silver2SSRS6spd Prefer to be blown! Drives: 2010 Silver/Black 2SS/RS Manual Join Date: Mar 2010 Location: Nor-Cal Posts: 2,677 View My Garage	Nothing looks better then a big block in an old Camaro, Vette or Chevelle. The easiest way to tell is by the valve covers. __________________ MagnaCharger TVS-2300 550rwhp 540 rwt and a radical suspension under the car.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
L99 how many cubic inch	soonerfanru2	Camaro V8 LS3 / L99 Engine, Exhaust, and Bolt-Ons	14	01-16-2011 11:00 PM
500 cubic inch V8 into a 1973 Z28	VRMMMM	1st & 2nd Generation Camaros	0	05-23-2010 02:16 AM
Cubic Inch	tnspd	Camaro V8 LS3 / L99 Engine, Exhaust, and Bolt-Ons	2	12-29-2009 12:48 PM
What cubic inch	BLU BY U	Camaro V8 LS3 / L99 Engine, Exhaust, and Bolt-Ons	5	11-24-2009 12:23 AM