I realize this is probably a stupid question to some people but i've never been able to find out so i thought i'd ask.

What's a 355?

Thanks.

A 355 is a rebuilt 350, typically bored .030 over, giving you a bore of 4.030", which with the 3.48" all adds up to roughly 355 Cubic Inches.

it's still really a 350 +.030 instead of a 355 but people like to say 355.

Bore x Bore x .7854 x Stroke x Number of Cylinders = Cubic Inch Displacment

4" x 4" x .7854 x 3.48" x 8 cylinders = 349.85 CID, rounded up to 350 CID

If the block is bored out .030", then the bore is now 4.030"

4.030" x 4.030" x .7854 x 3.48" x 8 cylinders = 355.12 CID, rounded down to 355 CID

Yea, its just an over bored 350. I still don't really understand why people feel the need to call it a 355 and not a 350 though... all it is is a 350 with some block maintenace done to it.

Meh, whatever, lol. I'm just rambling.

Thanks guys.

AJ- thanks for the formula that should come in handy.

It's also pi (3.141592654) x the bore radius squared x stroke x # of cylinders.

a SBC 350:
3.141592654 x 2 x 2 x 3.48 x 8 = 349.847759 cu. in.

a SBC 383:
3.141592654 x 2.015 x 2.015 x 3.75 x 8 = 382.667191 cu. in.

Whats the formula to make CI into liters?!

well, you could figure out the exact formula by looking up how many CI go into 1 L... or you could do it the half-***/lazy way that i did it.

305 CI x n = 5.0 L we know that since a 305 is 5.0L (more/less)

divide 305 by both sides of the equation and you get the following value.

n= 0.016393 (rounded)

This means that if you multiply this number by the number of cubic inches, the result should be in Liters. But, since the 305 CI = 5.0L is rounded, this number is not exact. To make it closer you can use the same formula except substitute in different values for the volumes. I used 350 CI = 5.7L.

In this case n = 0.0162857 (rounded)

The average of these 2 numbers should theoretically be closer to the actual value.

the average is = 0.016339

Most of you probably dont care how i got the number, soooo to make a long post short...

C.I. x (0.016339) = Liters

Remember! This is an approximation, an estimate... not the actual formula. Although it should be pretty damn near it.

61ci = 1 Liter

Divide engine CI by 61, and it will give you the size in Liters.

EX

427 / 61 = 7.0L

305 / 61 = 5.0L

Okay, without any rounding or "-ish's":

There are 2.54 centimeters per inch. Cube both of those, and you get 16.387064 cubic centimeters per cubic inch.

There are 1000 cubic centimeters per liter.

Do all that math, and you'll discover what is called a 350 (using 3.141592635898 for pi) is 5,733 cubic centimeters rounded to the nearest digit, or 5.733 liters.

Okay, what is it, really, with significant figures taken into account?

Because 355's are faster than 350's, 5 more cubes man! :lala: j/k I should have called my 305 a 310 (yes I rebuilt it before knowing how crappy it was)

stupid sig figs.... it would be 5.73 L since the number that you started with in that problem had 3 sig figs

because saying "350 with some block maintenace done to it." or "350 bored .30 over" is just too long.



btw, i have 408.7 ci (athough i dont call it a 409)

anyone want to guess what it is?

she's real fine my 409, my 4------0--------9! well i save my pennies and i save my dimes (giddy up giddy up 409)....

sorry your 409 statement just got me going. i am thinkin your 408 is destroked?? but if you were running a 408 mopar it would be from a 360 block that was stroked.

its a chevy.

but yea, if i said 409, everyone would think mopar.
and yes i have that song.










heh, i'll just post it... my first 400SBC was bored .40 over.. and yea i used to play the giddy up 409 song when i drove it because i thought it was funny...

The 409 was a Chevrolet V8.... the old "W" block.... that block came in a 348 and a 409. Available from somewhere about 57 to about 64. Sorry I can't be certain what years they were; as some of you probably already know, the 2nd thing you lose when you get old is your memory, but I can't remember what the first thing is supposed to be.....

Anyway I gotta agree, this business that has recently become popular of referring to a motor with a maintenance overbore by using some other number other than what it is, is obnoxious. A 350 is a 350 no matter how many times it's been bored for maintenance. Special numbers (383, 434, etc.) should be reserved for totally non-factory configurations. Calling a 350 a "355" just because it's had its bores cleaned up is nothing but pure monkey-spank IMHO.

i donno man...
ive seen you post the numbers 406 pretty often....



btw, yea they made a big block 409 but as i recall, they didnt badge it as such.. right? im not sure either, my memory is fuzzy about that too.... been awhile since i even thought about it...

So what exactly is wrong with calling a bored 350 a 355? How can the engine be called a 350 if it now has 355ci space?

Because then I'd have to call the 396 a 401, and everyone would think it's a Pontiac...

Go look at a piston or a piston ring catalog.

You won't see a "355" or a "357" or a "360" application.

You'll see 350 +.030" or whatever.

The reason you can call it a 350, is because it's a 350. Even if it's had about the thickness of a business card taken off of the cyl walls to clean up wear and provide a new surface. It's a factory size, with some maintenance. The change in the cubic inches is insignificant.

Now a non-factory size, such as a 377 or 383 or 434, is a different matter. It didn't start out life as any of those things, so it's not meaningful to talk about it using the factory dimensions, since they don't apply to it any more.

Just MHO.