are "engine size" and "engine displacement" the same thing?

rnmcd

Platinum Member
May 2, 2000
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If I read an ad for a vehicle and it says that it has a '350 engine' or that it is has a "5.7L V8 Engine" are they both discribing the engine size?

thanks.
 
Sep 29, 2004
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Originally posted by: SilentRavens
Yes, they both describe the volume contained within the combustion chamber(s) of the engine.

Really? I always though 350 refered to the physical size of an engine block and that the litre rating was just hte volume of air that is avaialble i nteh combustion chambers.

not a car guy so I always assuemd this.
 

jlee

Lifer
Sep 12, 2001
48,518
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106
Originally posted by: IHateMyJob2004
Originally posted by: SilentRavens
Yes, they both describe the volume contained within the combustion chamber(s) of the engine.

Really? I always though 350 refered to the physical size of an engine block and that the litre rating was just hte volume of air that is avaialble i nteh combustion chambers.

not a car guy so I always assuemd this.

350 == 350 cubic inches

5.7 == 5.7 liters
 
Aug 10, 2001
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350cc is smaller than the head of my Big Bertha driver. I think you mean 3500cc (i.e., 3.5L).

EDIT: Unless your measuring in cubic inches. :eek:
 
Sep 29, 2004
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Originally posted by: CadetLee
Originally posted by: IHateMyJob2004
Originally posted by: SilentRavens
Yes, they both describe the volume contained within the combustion chamber(s) of the engine.

Really? I always though 350 refered to the physical size of an engine block and that the litre rating was just hte volume of air that is avaialble i nteh combustion chambers.

not a car guy so I always assuemd this.

350 == 350 cubic inches

5.7 == 5.7 liters

Used to think the engine block was 350 cubic inches. Easy enough to measure via water displacement or weight. See google link above your explanaation ;)
 
Sep 29, 2004
18,656
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Originally posted by: Vespasian
350cc is smaller than the head of my Big Bertha driver. I think you mean 3500cc (i.e., 3.5L).

EDIT: Unless your measuring in cubic inches. :eek:

Also, not a car guy ;)
 

SilentRavens

Senior member
Aug 20, 2003
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www.mhughes.info
Originally posted by: IHateMyJob2004
Originally posted by: SilentRavens
Yes, they both describe the volume contained within the combustion chamber(s) of the engine.

Really? I always though 350 refered to the physical size of an engine block and that the litre rating was just hte volume of air that is avaialble i nteh combustion chambers.

not a car guy so I always assuemd this.

Eh, they are just two different measurements (imperial and metric) of the same thing.
 

Ornery

Lifer
Oct 9, 1999
20,022
17
81
Originally posted by: IHateMyJob2004
HOLY CRUD

I learned something new today! I have a new appreciation for 454's!
1970 Buick GS 455
  • The 455's was rated at 350bhp and a stump pulling 510lb-ft of torque. This was the highest torque rating of any production engine besides Cadillac's 472 and 500 cid V-8s, and no engine achieved it at a lower rpm (2800rpm).

    0-60 in 6.5 sec, 1/4 mile in 13.8 sec @ 101 mph.
 

spidey07

No Lifer
Aug 4, 2000
65,469
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obligatory "no replacement for displacement"

Do the displacement number include the volume in the head as well? As in entire compustion chamber?
 

Pacfanweb

Lifer
Jan 2, 2000
13,154
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Originally posted by: spidey07
obligatory "no replacement for displacement"

Do the displacement number include the volume in the head as well? As in entire compustion chamber?
No. The head CC has nothing to do with the cubic inches of the engine.
 

spidey07

No Lifer
Aug 4, 2000
65,469
5
76
Originally posted by: Pacfanweb
Originally posted by: spidey07
obligatory "no replacement for displacement"

Do the displacement number include the volume in the head as well? As in entire compustion chamber?
No. The head CC has nothing to do with the cubic inches of the engine.

thanks - I kinda thought that. So its really cylinder displacement.
 

Pacfanweb

Lifer
Jan 2, 2000
13,154
58
91
Originally posted by: IHateMyJob2004
Used to think the engine block was 350 cubic inches. Easy enough to measure via water displacement or weight. See google link above your explanaation ;)
Cubic inches isn't a measurement of the block itself. It is the diameter of the cylinders and the stroke of the crank.

Example: The only difference between a 427 and 454 Chevy engine is the crankshaft stroke. The bore of the block is the same.

Same with a 350 and a 327. Same bore, different stroke.

Another example is the 502 Chevy. Has a 454 crank, but a larger bore.

Displacement is calculated like this:
BoreXBoreX.7854XStrokeXnumber of cylinders.

When changing the stroke, you also have to change pistons. The new pistons will be the same diameter, but the position of the hole for the wrist pin will be higher or lower, depending on whether you're adding stroke or taking it away (destroking).

Obviously, if you take a 427 and just add a 454 crank, which is 1/4" longer, without changing the pin height the pistion would stick out of the block by 1/4".

I've known people who think you can change engine displacement by using longer connecting rods, but this is not true.
It's amazing how many good mechanics don't truly understand the finer points of the internal combustion engine.
 

Iron Woode

Elite Member
Super Moderator
Oct 10, 1999
31,086
12,593
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Originally posted by: Ornery
Originally posted by: IHateMyJob2004
HOLY CRUD

I learned something new today! I have a new appreciation for 454's!
1970 Buick GS 455
  • The 455's was rated at 350bhp and a stump pulling 510lb-ft of torque. This was the highest torque rating of any production engine besides Cadillac's 472 and 500 cid V-8s, and no engine achieved it at a lower rpm (2800rpm).

    0-60 in 6.5 sec, 1/4 mile in 13.8 sec @ 101 mph.
If we are quoting Buick GS 455:

455 Stage 1 = 360 BHP.
455 in fullsize car = 370 BHP.
455 Standard GS = 350 BHP.
455 in Riviera GS = 360 BHP Stage 1 engine.

Car Craft Magazine did a drag test on the 1970 GS 455 Stage 1 2 door and made a 13.38 sec 1/4 mile run and declared it the fastest muscle car of 1970.

 

Eli

Super Moderator | Elite Member
Oct 9, 1999
50,419
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Dear lord, the sheer ignorance displayed[by some] in this thread makes baby jesus cry.
 

Iron Woode

Elite Member
Super Moderator
Oct 10, 1999
31,086
12,593
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Originally posted by: Pacfanweb
Originally posted by: spidey07
obligatory "no replacement for displacement"

Do the displacement number include the volume in the head as well? As in entire compustion chamber?
No. The head CC has nothing to do with the cubic inches of the engine.
LOL