View Full Version : Head porting Northstar...

the recluse
01-12-14, 06:47 PM
I was looking into taking the heads off of the spare Northstar I have in the shop...if I port the heads and put them on a motor, does anyone think that I would have to flash the computer?

I know with the LT1 I'm building, the motor could definitely use a flash after I port and polish the heads and intake...any thoughts?

01-13-14, 12:36 AM
I have a spare set of heads that I plan to port on my Eldorado build that I haven't gotten to yet.

Most domestic carline heads that I've ever dealt with were 9-10 times exhaust restricted.

If you plan to redo a set if heads, in my opinion I'd leave the intake tract to the valve seat pretty much untouched. The valve seat into the bowl area that leads back up into the intake tract, I'd clean up and blend for a smooth transition.

The exhaust tract, I would probably do the same procedure.

If you disassemble the heads, please take pictures of the exhaust ports if possible and the bowl area under the valve, once the valves are removed.

Good luck.


Most porting I've ever done was mostly clean up. Nothing major, most factory heads just need casting flaws cleaned up.

01-13-14, 02:48 PM
The pcm wil adapt if you increase airflow

the recluse
01-13-14, 03:42 PM
The pcm wil adapt if you increase airflow

Excellent, was just wondering...I knew you couldn't really tune these PCM's, but if they have a good window on them...

01-13-14, 05:58 PM
The pcm will adapt for the most part.

I've never had issues with porting heads for most street driven vehicles with mass airflow systems.

When swapping in more radical cam profiles that move considerably more air and free flowing exhaust systems, there is the possibility of running lean, but in this case I truly don't see that happening with the stock cams and "cleaned up" heads.