LS1 with traditional 18436572 firing order?
02-07-2013, 01:24 PM
#61
If you install it dot to dot ( crank @ 12 o'clock, cam @ 6 o'clock) #1 will be at tdc firing. If you install them both @ 12 o'clock, #6 will be at tdc firing.
02-07-2013, 03:15 PM
#62
It does not begin with 6 unless you install the cam 180 out. Even then it really doesn't matter. It could start with 4, 2 or any other cylinder.
If you install it dot to dot ( crank @ 12 o'clock, cam @ 6 o'clock) #1 will be at tdc firing. If you install them both @ 12 o'clock, #6 will be at tdc firing.
If you install it dot to dot ( crank @ 12 o'clock, cam @ 6 o'clock) #1 will be at tdc firing. If you install them both @ 12 o'clock, #6 will be at tdc firing.
I went through this learning process when installing the LS1 cam for the first time, and couldn't understand why the valve events, as I knew them (SBC), would not coordinate with the LS1 cam lobes.
From "Joseph", who wrote the book, and verified by my own install...
"Glenn,
I'm glad you found my info helpful, not many people know the valve events for all 8 cylinders and when they happen. You would naturally assume with the dots aligned it would be the firing position of cylinder #1, when its actually the start of the intake stroke as far as the piston/intake valve is concerned. With the dots aligned cylinder #6 is the one to set preload/lash/ or for installing rockers.
Each 90* (720* / 8cyl = 90*) on the crankshaft gear is another cylinder firing, while each 45* (360* / 8cyl = 45*) on the camshaft gear is another cylinder firing. Having the timing cover off helps to watch the sequence.
Here's a copy/paste of a manuscript I'm working on that may help also:
Quote:
Originally Posted by Joseph
LSX Firing Order 1, 8, 7, 2, 6, 5, 4, 3
TDC Cyl. #1) Camshaft dot at 12:00 / Crankshaft dot at 12:00
TDC Cyl. #8) Camshaft dot at 1:30 / Crankshaft dot at 3:00
TDC Cyl. #7) Camshaft dot at 3:00 / Crankshaft dot at 6:00
TDC Cyl. #2) Camshaft dot at 4:30 / Crankshaft dot at 9:00
TDC Cyl. #6) Camshaft dot at 6:00 / Crankshaft dot at 12:00
TDC Cyl. #5) Camshaft dot at 7:30 / Crankshaft dot at 3:00
TDC Cyl. #4) Camshaft dot at 9:00 / Crankshaft dot at 6:00
TDC Cyl. #3) Camshaft dot at 10:30 / Crankshaft dot at 9:00
If you have that and the timing cover off you don't even half to measure how far you turned the engine over, just line up the dots to the correct orientation and install.
Thanks,
Joseph"
Last edited by gMAG; 02-07-2013 at 03:37 PM.
Gm didn't change it! The ls series has its firing order because it works the best for this engine.
06-16-2015, 01:05 PM
#64
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Aye. Some folks need to stay out of the car world. The cam swap nor engine swap ever came to fruition.
Dude didn't understand that this stuff costs money. I quoted him for reman and crate engines. Then the cam.
"Ala verga! Five hundurd for a Kam. Those just kill bottom end, don't they? My fourwiller only gained 3hp with a cam. Let's just drill holes in the air box and put some flowmasters on it. I don't want no used parts or redneck stuff on my baby."
Someone should tell the guy that the factory 256/258-100 @.040 cam in his fourwheeler is hard to improve on. I had a nice 220/224 113 .551/.525 planned for his truck. Honestly, I think firing order swaps are in the realm of diminishing return, especially when comparing the gains of adding 20 degrees of camshaft duration. Also, since we would have added power with the cam, the loss from the order swap would be really small, assuming the ls order makes the most power. Oh well. In the bible of power, let's stick to the formula of mild cams, ported heads, and headers for a good daily driver. Punt the acoustic art nonsense for Jeremy Clarkson.
Dude didn't understand that this stuff costs money. I quoted him for reman and crate engines. Then the cam.
"Ala verga! Five hundurd for a Kam. Those just kill bottom end, don't they? My fourwiller only gained 3hp with a cam. Let's just drill holes in the air box and put some flowmasters on it. I don't want no used parts or redneck stuff on my baby."
Someone should tell the guy that the factory 256/258-100 @.040 cam in his fourwheeler is hard to improve on. I had a nice 220/224 113 .551/.525 planned for his truck. Honestly, I think firing order swaps are in the realm of diminishing return, especially when comparing the gains of adding 20 degrees of camshaft duration. Also, since we would have added power with the cam, the loss from the order swap would be really small, assuming the ls order makes the most power. Oh well. In the bible of power, let's stick to the formula of mild cams, ported heads, and headers for a good daily driver. Punt the acoustic art nonsense for Jeremy Clarkson.
06-16-2015, 02:26 PM
#67
OP should just sell the LS1 and buy a LT1 car and end up with quite a bit extra $$ for mods.... take a step back in technology, but take a step forward in old school small block sound! The only LS engines I've ever heard that sound as good as my LT1 are a full bolt on cammed LS7 Z06 and a LS9 ZR1 I saw/heard in person 
Last edited by ahritchie; 06-16-2015 at 03:02 PM.
08-03-2021, 10:39 AM
#69
TECH Senior Member
From what I gathered from the info on this article, firing order doesn't affect the sound.
08-05-2021, 11:03 PM
#72
I’ve noticed this phenomenon as well.
It’s like a virus.....
Perhaps Rona caused all sorts of folks to go buy LS powered vehicles?
As an aside, I worked on an old school 427 rat motor at the shop that had a custom cam converted to the LS firing order. Completely messed me up when I changed plug wires. 😊
Still, it sounded just like a big block.
It’s like a virus.....
Perhaps Rona caused all sorts of folks to go buy LS powered vehicles?
As an aside, I worked on an old school 427 rat motor at the shop that had a custom cam converted to the LS firing order. Completely messed me up when I changed plug wires. 😊
Still, it sounded just like a big block.
