I think this would be the correct place to make this thread...?

So, I just started my first semester at a technical college studying automotive maintenance and high performance technology, and I'm fairly new to all of the more technical aspects of the internal combustion engine and creating more performance so I may show some of my ignorance here.
One day, after school let out, a few of us were hanging out shooting the proverbial **** and talking cars when a guy brings up this interesting theory of altering the firing order of a SBC that he's building. I don't mean to give him credit for this "theory" as I'm sure he's not the first to think of it, but I had never heard of doing such a thing nor had it ever crossed my mind. His intent would be to alter it in such a way as to not fire on the same bank twice in a row. Thus, making the engine run more "smoothly, balanced, and efficient". The factory firing order of the SBC (possible the Ls, too. I'm not sure.) is 1-8-4-3-6-5-7-2. The 5-7 fire is when bank 1 is fired upon twice in a row. As the theory goes, by changing the firing order to something such as 1-8-3-6-7-2-5-4 (there may be a more efficient firing order. It's fairly irrelevant for my questioning) where spark is constantly swapping banks, the engine would run more efficiently. My rookie, and possibly ignorant, understanding would be that this could easily be done by simply changing the plugs around on the distributor. Maybe a custom cam and crank would be necessary, too? Again, I really don't have a full understanding of what I'm talking about.
My questions would be: Does this theory actually hold any weight? Has it been done? Say I wanted to do this with an Ls engine: Can it be done and how?

I want to make clear that I personally do not care to do this. I was just hoping to get some answers and insight on the matter. I've accepted that GM engineers are smarter than myself, and that they designed things the way they did for a reason.

 

Ford small blocks have used this for years....Even the newer LS engines share the older Fords firing order...

You can swap the firing order on the older SBC engines but you will need a special cam to also time the valves correctly...I remember reading a carcraft article that did this swap with very similar cam specs...although not a huge gain, there was a smoothness factor and 5-10 hp if I remember correctly

 

Here is some better info , read up on it...

http://www.hotrod.com/techfaq/113_07...s/viewall.html

 

Cool. I'll definitely read up on that.

I see you're from St. Louis and that you have an "Ls1 swapped '88 Ram project". So...WAS THAT YOU AT GATEWAY FOR T&T LAST WED. NIGHT???

 

STL unite! hahaha if you need a tranny brads the guy! i called a week or so ago and got a pretty good rundown of what his built tranny has! but that firing order would be pretty cool for sure!

 

Wait...wait...wait...is silverz28camaro Brad Kimbler? Oddly enough, I'm actually in the process of getting a 4L80 from him to put in my turbo Ls swapped '87 Grand National project... I'm just awaiting the word on some "13-10" connector so I can ship my harness back to PSI for some alterations.
Altering the firing order would be neat just so you can say you did it, but I'm not looking to do that just yet. I just want to toss the 6.0 in with the turbo and a few other goodies and without too much headache. Might think of doing that if I ever Ls swap my '81 Camaro.

 

Small world..LOL, I left ya a message on facebook about the 80E

 

 

If I were switching up the cam I'd do it, but otherwise I wouldn't waste my time with a SBC lol

 

Yeah, you ain't kiddin'...
Received and replied!

So cool! You made me $5 that night! I met with a buddy who didn't see your first pass so we made a little wager on what you would run. Naturally, I let him pick his time first.

Not building a SBC...I was just curious. However, the Ls that I was planning on putting into my '81 Camaro will be going into the '87 GN so a 355 SBC and 4-speed may find their way into the Camaro.

 

What time did he guess? I boiled the tires off on my second run....my WOT switch kept turning on and off throughout the pass, should have been another 12 sec run...but was a 13.0 pass. turns out if my foot is more to the right side of the pedal it feels like WOT but only logs 95%..just have to pay more attention next time, or trim the carpet up a tad

 

I don't remember exactly. He was a little leery why I asked so he guessed somewhere in the 16's (no doubt a respectable time for an older, lifted Ram). Shortly after this he saw the purge. After I got quick jab to the arm, he was reaching into his wallet for that Lincoln. It wasn't until later that night when Shawn posted the video that we knew it was Ls swapped. And just last night I found out it was yours lol.
Right on. You gonna' make it out any more this season in that thing?

 

Finally read the article. Seems like the theory doesn't really work. People have had success, but it cannot be explained...?

 

You can buy a cam from Summit Racing off the shelf for a SBC to do this.Ford has different firing orders depending on witch cam you use.

 

Yes, it's been done a billion times. Every form of motorsports has altered the firing order at one time or another on any given make of engine. There has even been engines that have been modified so that 2 cylinders fire at once, engines that have had the crank phasing changed so the engine fires at differnet times (instead of every 90 degrees), flat cranks, reverse rotation like marine for atomotive racing, etc etc. Anything you can possibly think of has been tried, raced and shelved again.

 

Ah, very interesting! Very cool. I figured it has been done, and as I stated in my original post, I'm new to all of this so there's got to be tons of stuff that I haven't yet heard of.