so yeah, it doesn't really matter LOL. 
LS3 cubic in. displacement
Thread Starter
Racer
Joined: Jul 2001
Posts: 455
Likes: 2
From: manahawkin,nj
LS3 cubic in. displacement
GM says LS3 is 6.2 liters but I think they exagerate cause that would be 378.344 cu. in. When I calculate bore & stroke I dont get that high. What you all think ???
Le Mans Master
Joined: Jul 2005
Posts: 5,328
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The bore/stroke of an LS3 is 4.065" (or 10.325 cm) and 3.622" (or 9.2 cm). Displacement in liters is L=Bore²*Stroke*pi*2/1000 or L=10.325²*9.2*3.14*2/1000= 6.162L which rounds up to 6.2L, no exaggeration to it.
The LS7 is 427.65 in³ which is 428 in³ when rounded but GM calls it a 427 in³ because they truncate the number...their choice. The new Chrysler Hemi isn't actually a "Hemi" because the combustion chamber isn't truly hemishperical (it incorporates squish/quench areas for emissions) but it shares the same crossflow valve arrangement with the old Hemi from the 50's/60's...their choice. BMW calls their cars the "ultimate driving machine" when they are far from it...their choice.
The LS7 is 427.65 in³ which is 428 in³ when rounded but GM calls it a 427 in³ because they truncate the number...their choice. The new Chrysler Hemi isn't actually a "Hemi" because the combustion chamber isn't truly hemishperical (it incorporates squish/quench areas for emissions) but it shares the same crossflow valve arrangement with the old Hemi from the 50's/60's...their choice. BMW calls their cars the "ultimate driving machine" when they are far from it...their choice.
Team Owner
Joined: Apr 2008
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From: Middle TN by way of KY, OH, VA, IL, CA, FL, NY, SC, HI
Lots and lots of examples like this out there.
Drifting
Joined: Apr 2010
Posts: 1,443
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From: Bristol raceway area
In 1970 the bore was increased .030 to 4.126 = 402 cu. in.
What i heard was that management kept it at SS396 as not to "change a good thing". Insurance played a big part as well because anything over 400 cu.in. was more costly to insure.
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Team Owner
Joined: Feb 2001
Posts: 27,254
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From: Short Hills, NJ
It always baffled me that they had 348, 366 and 396 (later becoming 402) big blocks and yet a 400 small block as well.
Now we have 427ci (or even 480+ci if you want to build it) small blocks.
You're partly correct. The big block 396 Chevy started in '65 with a 4.094 bore x 3.76 stroke = 396 cu. in.
In 1970 the bore was increased .030 to 4.126 = 402 cu. in.
What i heard was that management kept it at SS396 as not to "change a good thing". Insurance played a big part as well because anything over 400 cu.in. was more costly to insure.
In 1970 the bore was increased .030 to 4.126 = 402 cu. in.
What i heard was that management kept it at SS396 as not to "change a good thing". Insurance played a big part as well because anything over 400 cu.in. was more costly to insure.
True.
Team Owner
Joined: Apr 2008
Posts: 31,800
Likes: 2,397
From: Middle TN by way of KY, OH, VA, IL, CA, FL, NY, SC, HI
You're partly correct. The big block 396 Chevy started in '65 with a 4.094 bore x 3.76 stroke = 396 cu. in.
In 1970 the bore was increased .030 to 4.126 = 402 cu. in.
What i heard was that management kept it at SS396 as not to "change a good thing". Insurance played a big part as well because anything over 400 cu.in. was more costly to insure.
In 1970 the bore was increased .030 to 4.126 = 402 cu. in.
What i heard was that management kept it at SS396 as not to "change a good thing". Insurance played a big part as well because anything over 400 cu.in. was more costly to insure.
Drifting
Joined: Apr 2010
Posts: 1,443
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From: Bristol raceway area
Melting Slicks
Joined: Aug 2006
Posts: 2,167
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From: Powell TN
Cruise-In VIII Veteran
The new 5.0 Ford motor is a good example. Rated at 412 hp, there are many dynoing 385-390 hp bone stock. That equates to more like 450-460 hp....same thing they did with the "Terminators".
Drifting
Joined: Apr 2007
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From: ABQ NM
Safety Car
Joined: Sep 2006
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From: Cheektowaga NY
St. Jude Donor '08
The bore/stroke of an LS3 is 4.065" (or 10.325 cm) and 3.622" (or 9.2 cm). Displacement in liters is L=Bore²*Stroke*pi*2/1000 or L=10.325²*9.2*3.14*2/1000= 6.162L which rounds up to 6.2L, no exaggeration to it.
The LS7 is 427.65 in³ which is 428 in³ when rounded but GM calls it a 427 in³ because they truncate the number...their choice. The new Chrysler Hemi isn't actually a "Hemi" because the combustion chamber isn't truly hemishperical (it incorporates squish/quench areas for emissions) but it shares the same crossflow valve arrangement with the old Hemi from the 50's/60's...their choice. BMW calls their cars the "ultimate driving machine" when they are far from it...their choice.
The LS7 is 427.65 in³ which is 428 in³ when rounded but GM calls it a 427 in³ because they truncate the number...their choice. The new Chrysler Hemi isn't actually a "Hemi" because the combustion chamber isn't truly hemishperical (it incorporates squish/quench areas for emissions) but it shares the same crossflow valve arrangement with the old Hemi from the 50's/60's...their choice. BMW calls their cars the "ultimate driving machine" when they are far from it...their choice.
LMAO!!! So true!
Le Mans Master
Joined: Jul 2005
Posts: 5,328
Likes: 405
Read my post again...I was talking about the LS3 specifically. Last time I looked, it has eight cylinders.
Just for you, the displacement formula (in liters) for any engine is:
L=Bore²*Stroke*pi*(# of cylinders/4)/1000 with the bore/stroke in cm.
Just for you, the displacement formula (in liters) for any engine is:
L=Bore²*Stroke*pi*(# of cylinders/4)/1000 with the bore/stroke in cm.
