# How to tell the size of an engine

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Hey, me and my friend were talking about engine size in his dad's truck and he was told by this guy that it was a 350 small block chevy (1989) and he knew by looking at the spark plugs. Well i was told its not possible so i was wondering what ways you can tell if it is a 350 or if it's something else (ie. by using intake, valves, headers, etc.). Any help would be useful. Also would you be able to find out by using the internet to run the block number? Thanx.

car_crazy89

Lots of experienced people can tell just by the general shape of an engine, more-so the older engines than the newer ones. Since now they stamp "2.2L" right on the plenum, so there's no need to memorize it. On older carburated vehicles they used to stamp it on the filter housing, but once that got dirty/changed for a higher flow housing, that was gone, and they only way to tell was if you knew what the engine itself looked like. Also, the 350 is an extremely common motor to say the least.

88GrandPrixSE

Chevy small blocks look dimensionally the same, and to claim that you can tell what engine it is by the plugs is absurd. A 305 and a 350 dressed the same will be identical looking, so he is at best, guessing. Small blocks VS. big blocks on the other hand are easy to tell apart.

Sick88Tbird

You could always take it apart and measure the volume of each combustion chamber. That always works best.. Who knows it might not be a 350, it could bea 349.201.

DSMer

Measuring the volume of the combustion chamber wouldn't tell you dick, if you wen't by the combustion chamber each vehicle would be about (made up number) 10cc's per cyl.

88GrandPrixSE

Hmm so if 1cc = 0.0610 cubic inches(1cubic inch = 16.38cc), using your logic the engine would really be 4.88189 cubic inches? Even for a made up number you're still off by about 345 cubic inches, and I suppose GM just wanted to pull the number 350 out of their asses. Or maybe if he used one of those big ass needle thingamajigys that measure volume and came out to oh say 712.5mL per cylinder, multiply that by 8 wich gives us 5700mL or 5.7L wich roughly converts to 1L = 61.02 cubich inches. Multiply 5.7L by 61.02 and what do yah know we get 347.81 cubic inches of displacement. More commonly known as a 350 motor. N hey what do you know? My fathers Camaro has 5.7L of displacement and it has 350 motor in it.

Whos the dick now? That'd be you.

DSMer

How can you even talk about an engine when you can't even tell the difference from a combustion chamber and cylinder. Oh smart one? That's right, you're in reality a retard. Yes, I'm tired of your idiocy and cockyness.

Who's the retard now? That'd be you.

Not to mention you can't just measure the cylinder bore/length to determine displacement, it doesn't work like that, but of course you're so smart and realize that they don't just make up an engine and measure it and bam,
"houston, we have 6999cc's of displacement", there's a few more factors that determine displacement.

You can post when you know what you're talking about. Otherwise, shut up because we're all tired of your arrogance.

88GrandPrixSE

Haha you can't be serious. The combustion chamber is where the combustion takes place. Thats why they call it a combustion chamber. Some people would also refer to it as the engines cylinders(Just in case you don't know the cylinders are where the combustion takes place). Now is it me that can't tell the difference or is it you? Are you that obtuse or are you playing with me to make yourself sound smart?

No one said anything about cylinder bore or stroke(the proper term is stroke not lenght). But hey since you mentioned it, it is in fact possible to find the displacement from the bore and stroke. For example my V8 engine has a 4.000 bore and a 3.48 stroke. Together the equal 349.847 cubic inches(5731cc's) more commonly known as the 350. My Mitsubishi 4G63T has 2.0L ofs displacement. If I were to fill all of the 4 cylinders up with water they would all hold .5L of water.

But since you're so smart and know how engine displacement is figured out how about you enlighten us with your overwhelming years of knowledge. Mr. I work for Chrysler. And taking out their trash does'nt mean you know any and everything about what they do, but none the less I'll give you a few minutes to thumb through to your "mind" and find out exactly how it is that you can find engine displacement. There are many ways so I'd suggest you get cracking. I'll be waiting....

By not responding you accept that you are infact wrong and that I was correct.

DSMer

As I said, you should not reply if you have no idea what you're talking about. The combustion chamber is in the head, you know that little cut-out in the head, yes, that is what is called a combustion chamber, cylinders are in the block, combustion chamber is in the head, good job on making an ass of yourself.

Once again you made yourself look like a retard. Stroke is the stroke of the crank, length is the length of the bore. Think of it, if the piston went all the way to the bottom of the cylinder it would fall out/jam/break things. Good job again. As I said before, come back when you know how engines work.

Here's an engine to ponder, GM 2.8/3.1, identical block, different crank/rods/pistons, so in your logic they both should be the same size, but they aren't. Where did the extra 300cc's come from?

Never said I worked for Chrysler. We work very closely with them because they offered my father a job to run the shop there but he didn't take it.

By not responding you accept that infact you are a retard and that you know nothing about the components of an engine.

88GrandPrixSE

Look guys...

Engine displacement is calculated simply by multiplying the radius of the bore squared by Pi and multiplying that by the stroke travel of the piston and that figure times the number of cylinders in that engine.

Let's take a Chrysler 383CID V-8 as an example.

Bore = 4.25
Stroke = 3.38 (rounded, actually it is 3.37.5 but noone usually goes by that figure)

The radius, half of the bore, is 2.125.

2.125 X 2.125 (bore radius squared) X Pi X 3.38(piston travel, stroke) X 8(# of cylinders)

- That up there cleaned up is 2.125 X 2.125 X 3.1416 X 3.38 X 8 = 383.59 Cubic Inches.

DodgeRida67

Exactly, but it's entertaining making fun of that guy, he thinks he's all that, when if you don't know what you're talking about, don't say anything at all to reduce the risk of making yourself look like an ass.

88GrandPrixSE

Listen carefully. A combustion chamber and cylinder are not the same.

What do you mean " it is in fact possible to find the displacement from the bore and stroke."? That's how it's done.

DodgeRida67

As I said, you should not reply if you have no idea what you're talking about. The combustion chamber is in the head, you know that little cut-out in the head, yes, that is what is called a combustion chamber, cylinders are in the block, combustion chamber is in the head, good job on making an ass of yourself.
Congratulations you've proven yourself worthy... Although to be technically correct the combustion chamber is'nt "IN" the heads. The combustion chamber would be classified as the area above the piston at TDC.

Once again you made yourself look like a retard. Stroke is the stroke of the crank, length is the length of the bore. Think of it, if the piston went all the way to the bottom of the cylinder it would fall out/jam/break things. Good job again. As I said before, come back when you know how engines work.
Damn I thought you were on a role there. Incorrect, while stroke does indeed refer to the crank, stoke is distance that the crank moves the piston fromt BDC to TDC. The actual lenght of a cylinder is never used in calculation because there are parts of the cylinder that will never see the combustion. Therefore the correct term to use would be "stroke" not lenght. Bore and Stroke, not Bore and Lenght. You passed the first test, surely you could have gotten this, just open a fecking automotive dictionary. Come on my little lab rat you can do this...

Here's an engine to ponder, GM 2.8/3.1, identical block, different crank/rods/pistons, so in your logic they both should be the same size, but they aren't. Where did the extra 300cc's come from?
Self explanitory dipshit. A different crank can produce a lesser or greater stroke(that thing you're not familiar with) wich would give you the extra 300cc's. Surley YOU should have known that... Jeez, you're doing horribly on this test.

Haha, you gotta be kidding me... I'm aware of what a combustion chamber is.

Again, thanks for the math but as I said before. All one needs is the Bore and Stroke to produce the displacement of any given engine. However that is'nt the only way.... However Mr..."you can't just measure the cylinder bore/[STROKE] to determine displacement, it doesn't work like that,there's a few more factors that determine displacement." does'nt beleive so.

Ok cmon Mr.Chrysler man, for extra credit. You can still redeem yourself by naming at least one other way to figure out engine displacement.

DSMer

Okay genius, how else do you determine the displacement of an engine other than doing the proper math based on bore and stroke. You can't tap dance out of this because I already know the answer. You're on.

vwhobo

Not quite sure of the specific name of the tool but I've used it in Chemistry class on couple of occasions. Its a large graduated cylinder with a spout on the bottom and it pours a measured ammount of fluid. What I've seen some engine builders do is use one of these to meassure the ammount of fluid(usually just water) that the cylinder would hold and they put some kind of clear plastic block over the cylinder head and sealed the surrounding edges with jelly or wax. Something to keep the water from overflowing.. Don't know what the proper name is, but I've seen a few guys do it with engine blocks and valve heads. Not sure as to how accurate that is but thats one I know of.

The other I heard from reading one of Wally's post that had something to do with pressures. Absolute manifold pressure to be exact, but he may not have been talking about an accurate measure I'll have to find the post to clarify...

DSMer

Sorry, you lose. While the procedure you're describing will in fact tell you what the displacement is, it is a mechanical measurement. Great for CCing heads but not for what we're talking about, or what you're bitching about here.

What you are doing is a way of physically measuring. You can only mathamatically determine the displacement of and engine by using the appropriate equation ans mentioned above. Time for you to appologise.

vwhobo

You do realize that's what I just said, no?

Mistake #1

Once again, I'd already said that a different crank/rods/pistons would change the displacement. That was my reasoning for bringing it up.

How many times do I have to tell you I know what a stroke is, it's you that doesn't seem to, as you seem to think the whole cylinder is part of the stroke.

Mistake #2

All I was saying is you can't just take a block and figure out the displacement, you have to have the block, crank, rods, pistons and heads to determine displacement.

Mistake #3

Wow, you're good. 3 mistakes in one post.

88GrandPrixSE

Well if it does in fact tell you displacement and it will work, the whats the problem? If you can use a mechanical measurment to get the volume of the cylinder then whats wrong with it? I'm not sure of the accuracy but I've seen it work. Engine was overbored, they did that test it came out to 2.4L when they did it mathematicly it also came out to 2.4L....

It may be inneficient in that it would just be easier to use math, but if it can indeed tell you displacement, whats wrong with it?

**EDIT**

Well I said you could use Stroke and Bore, assuming you have a block you'd have the bore. How else do you think you could get stroke? By guestimating where the piston and crank would travel? According to the calculations the head would'nt be necessary... Just the Block itself.., with its parts still in it of course..

DSMer

You have been a bad boy DSMer and you must be punished. Now go to the nice man and tell him you are sorry. I will deal with you when we get home. :mrgreen:

Wally

Is this serious?!?!? :screwy:

I thought it was cleared up back there when someone said multiply piston area (or cylinder x-section area) by stroke of piston by number of cylinders to get displacement.

Why would you start going on about using burettes and other assorted chemistry apparatus (apparatii?).
Just admit you were wrong and that you were trying to figure out a complex way to solve a simple problem.

As for filling a 2L engine with 2L of water.... wouldn't the pistons all be at different parts of the cycle at any one time? Tell me how then you would just start filling up cylinders?

Sometimes it takes a bit of courage to admit you may not know everything. I know I don't know everything, but I thought that it would be difficult to get all 4 cylinders in a 2L engine to be at the bottom of the stroke.

windsonian

Well you could fill one at BDC with water then multiply by the number of cyls. But filling it with something.... that'd be somewhat... inneffective to say the least :roll:

88GrandPrixSE

I'm sorry for asking a question that started these problems, i thought it would be a relatively simple answer. But thanx again for your replies and i'll leave it for you all to work out these other problems.

car_crazy89

It's bound to happen ...
Did you find out what you needed to know amongst it all?

windsonian

Thats the name of the tool. I think its a burette.. and this is usually done to an engine that has just come back from machining. You turn the crankshaft until each piston is at BDC, just as you would if you were checking the compression of each cylinder. Multiplying would be inaccurate because one cylinder may be off.

Its not difficult. Most 4 cylinder engines fire in a 1/4 and 2/3 position. Wich would mean you would only have to turn the crank one full time. Again as I said simple math would always be easier, but this is indeed a way you can determine cylinder volume.

DSMer

Not to mention how inaccurate it would be with all the different piston types used. For instance I bought a set that would soak up 5CC's each. That would be 40CC's off. :hi:

DodgeRida67

Yes, i think i found out what i needed to know. Thanx for your help. And ya I know problems occur sometimes cause i've read some in other threads. Thanx again. :thumbs:

car_crazy89

To convert engine displacement (litre) to cubic inch just multiply by 61. For example 2.0L is 122 cubic inch

jman

why is everyone arguing about a very simple thing?

DSMer has been a bad boy?

CarEXPERT