I'm looking at getting an AI cam and wanted to know if there are any advantages to running an LS firing order? I read the scavenging is improved but was wondering if there's anything else. I have 24x so repining the harness and changing a few numbers in the tune is no big deal.

 

I don't think there is any real effect on scavenging and no power to be had. The reason for swapping the firing order is to change the most stressed crank pins from 1,2,3 to 2,3,4 and reduce crank torsion. You move the load closer to the flywheel so the crank flexes less, therefore the harmonic balancer has to do less work so the motor runs smoother and more reliably when pushed to the limit. Very very small difference here and only a theoretical improvement.

I didn't know AI did the 4/7 and 2/3 swaps. I looked into having LSM make a billet cam with LS1 order for my motor a while back but eventually abandoned it because I'm cheap.

 

OP, If you get a cam with LS firing order wouldn't you have to get a crank with the LS firing order too?

 

Just a regular dual plane v8 crank, throws are the same

 

gotcha, not worth the extra $400 then

 

There's a reason why the 4/7 swap was popular with racers, and then the fact that GM themselves went to the LS firing order. The factory has access to equipment which can test things way beyond the scope of a race team. They found that the bearing loads were more even when using the LS firing order. That can lead to a smoother running engine and/or increased bearing life. I've never seen any back-to-back tests of standard firing order versus 4/7 swap, where the 4/7 swap lost any power. It's worth a shot to me if it's only a few bucks more. My LSM cam was no additional charge for altering the firing order.