How many cubic inches is a N*?

[STS127]

How many cubic inches is the Northstar? In my owners manual it says 279 but whenever I do a parts search on a website it will say 281. Which is it?

[ewill3rd]

I wouldn't call this gospel, but the conversion factor I always used is Liters times 61.02 = cubic inches.
It works mostly, but it is not anything scientific.
That would put the N* at just over 280.

An online volume calculator that I found says :4.6 liter = 280.709221649 cubic inch

It looks like 281 would be the winner, but it depends on who is doing the math I guess.

[I~LUV~Caddys8792]

I've heard the Northstar is 279 and the Ford 32 Valve 4.6 is 281.

[Dadillac]

Also keep in mind that the N* technically could be as low as a 4.55 liter engine. Manufacturers round off the number, and are supposed to do so to the nearest tenth. So the conversion for a 4.55 engine is 277 ci.

Don

[eldorado1]

A northstar has a 3.66" bore and a 3.31" stroke, for a total displacement of 278.6 cubic inches

[Flynn]

1/2 bore, squared x pi x stroke x No. of cylinders = displacement

(for you who want the formula for future reference)

[ewill3rd]

Sure... then there is that....
There is a little space in the combustion chambers too.

[AaronZ34]

Originally Posted by ewill3rd

Sure... then there is that....
There is a little space in the combustion chambers too.

That has absolutely nothing to do with displacement.

[Flynn]

Displacement is defined as the "swept" volume of the cylinders per 1 complete cycle, so that excludes the combustion chambers.

[ewill3rd]

Wow, you sure showed me up.