Why did Cadillac go with S/C 4.4L instead of S/c 4.6L for the newest V-series car?

I know GM has been playing with the 4.4L Northstar for a little while (Bonnie GXP concept) 4.2L S/C northstars were also used in the Evoke and Imaj concepts.


So what does the 4.4 have that the 4.6 doesn't?

 

4.4 has thicker walls to handle the power.

 

could have found they got better reliability out of the 4.4 with an SC and that they could bppst up the psi

 

Bingo. GM said that they wanted the thicker cylinder walls to deal with the increased cylinder pressure.

 

The Northstar V8 has tighter bore spacing than the Chevy smallblock - or even Infiniti's VK-series V8. The bore spacing issue is why the Northstar V8 hasn't grown in displacement, and it's also why the S/C was de-bored for the sake of durability.

Why does the STS-v have 4.4 liters instead of the 4.2 like the Evoq and Imaj? The 4.2 liter had the same bore as the then-current 3.5 liter "Shortstar" V6. GM had planned on continuing the "Shortstar," and the Northstar based V6 was planned for the Cadillac CTS and the other Sigmas. When the Shortstar was cancelled (for some very good reasons) there was not point in maintaining the smaller bore size, so we've got a 4.4 liter S/C Northstar.

The ironic part is that the Northstar is on its way out and the replacement will probably share its block architecture with the Chevrolet small-block V8.