Joseph Forbes

I was wondering if anyone has done this firing order change on a LS1. I honestly hate the sound of LS1's and wish GM stuck with the traditional Chevrolet firing order and didn't copy off Ford. So has anyone ever seen an LS1 with the old school firing order or any threads on this?

18436572 > 18726543

badazz81z28

iTrader: (6)

I must be tone deaf. I can't tell a noticable sound difference. I would suspect fo you get a custom cam and a re-program, you could do it. I thought I read though that the firing order change from old school free'd up some ponies.

Joseph Forbes

It just makes the car sound softer and idles smoother, the difference would be compare an LT1 to a LS1 in sound.

JACornell

I have heard of the 4-7 swap in firing order, possibly do a search on here for it.

NemeSS

iTrader: (127)

i prefer the ls robotic sound.
dont see the point in using another firing order. if it was beneficial in any way. every one would be using it. its not gonna make any more power, or idle or sound better.
cam used, scr, exhaust used, calibration and many other variables contribute to the sound the engine makes besides just the firing order.

BIG_MIKE2005

iTrader: (116)

This hits it on the head.

Joseph Forbes

it would drastically change the sound and it would make it sound like a traditional sbc, you pretty much said a ford sounds just like a chevy.

Taspeed

iTrader: (1)

the lsx motors sound different for several reasons. only 1 of them has to do with firing order. Aluminum and iron blocks sound different as well. The harmonics of the engine itself are going to make it sound different.

AceHaag

iTrader: (12)

a BBC and a SBC sound drastically different but use the same firing order

Joseph Forbes

that's like comparing a 350 to a 383, bigger cubes = bigger sound.

bww3588

iTrader: (49)

Just because ford uses the same firing order does not make it sound like an ls1. Ford numbers their cylinders differently and everything on the crank and cam correlates with that.

Gm didn't copy off ford, they switched 4 and 3 for 7 and 2 for better engine harmonics and balance. They change stuff for a reason, not just because some other manufacturer is doing it or because they get bored pushing a pencil across the desk.

Changing the firing order back to the old order would entail a lot of programming and a custom cam, and in the end, You would have an engine that sounds nothing like a small block Chevy, makes less power and vibrates more.

bww3588

iTrader: (49)

Bigger cubes, bigger sound makes some sense, but I have heard a 406 small block and a 402 big block and They sound totally different. It's all in the head layout, cam profile and compression ratio.

Big blocks have canted valves, and equally spaced exhaust ports, that will change the sound more than you think.

gectek

iTrader: (2)

Its also about the companion cylinders and loading the mains in a more specific order helps maintain harmonics problems and crank deflection as well. There are plenty of articles about it, so instead of being a rather uneducated meat head, why do you not research instead of asking why?

You realize that is not the first time GM did that right? With the LS engines and the firing order. It USED to be called the corvette firing order.
A larger fad in the SBC and BBC community is to do the 4-7 swap, where you actually GAIN power from the same cam grind, but operate with an LS style firing order.

gregrob

iTrader: (8)

Mine is halfway there. (4/7 swap)

http://www.youtube.com/watch?v=NbVlz...9&feature=plcp

bww3588

iTrader: (49)

The 4-7 swap is done in small blocks to smooth out the harmonics of the engine and take better advantage of a 180 degree dual plane intake.

bww3588

iTrader: (49)

With the firing order of the ls1 the way it is, and a semi single plane intake, changing the firing order will gain you little to nothing.

The Alchemist

iTrader: (19)

Wouldn't you have to change the crank, cam, injector, coil to change the firing order?

bww3588

iTrader: (49)

as long as you switch corresponding companion cylinders (meaning both at TDC or BDC at the same time) you can switch the firing order.

thats why you see the common 4/7 swap on old small blocks. they are both on TDC at the same time, one is just on compression, while the other is on exhaust.

but yes, you do have to change the cam to open and close the valves on the correct cylinder. basically on a 4/7 swap, all that is done is the lobe location is switched between the 2 pair. and change the programming in the tune to fire the correct coil/injector at the right time.

bww3588

iTrader: (49)

thats only half of the OP's question...or rather complaint...

to go from an LS1 firing order to an older small block firing order you have to swap 4-7 and 2-3

the easiest way to find companion cylinders is to write the firing order out...

18436572

split it and put the first 4 numbers over the second 4 numbers.

1843
6572

you have 1/6, 8/5, 4/7 and 3/2 as companion cylinders. any of these can be swapped, however, unless you know exactly what you are doing, you can easily put your engine into a death shake and destroy it.

thunderstruck507

iTrader: (18)

What is the engine in that you hate the sound of?

You will be better off using a lopey cam and a good dual exhaust set up. If I had videos of before and after my ls1 swap I bet you would be hard pressed to hear much difference between the 355sbc and the cammed ls1.

If you have an fbody, get rid of the shitty y pipe exhaust system and you will be much happier. A y pipe can ruin the sound of anything.