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HawkX66 01-13-2017 12:22 PM

Gen 6 firing order question
 
When I ordered my cam all the vendors only listed cams for 96-00 Gen 6 motors. I thought Gen 6 was Gen 6 so I contacted Lunati and told them what I had and they suggested 20010723. I didn't realize GM changed the firing order at some point. Is that going to affect me? Mine is a 2015 Gen 6 489ci. I was assuming it had the traditional 18436572 order. Bad assumption?
Is that the only difference between the 96-00 Gen 6 and the 01-up Gen 6?

Thanks.

MILD THUNDER 01-13-2017 04:15 PM


Originally Posted by HawkX66 (Post 4519331)
When I ordered my cam all the vendors only listed cams for 96-00 Gen 6 motors. I thought Gen 6 was Gen 6 so I contacted Lunati and told them what I had and they suggested 20010723. I didn't realize GM changed the firing order at some point. Is that going to affect me? Mine is a 2015 Gen 6 489ci. I was assuming it had the traditional 18436572 order. Bad assumption?
Is that the only difference between the 96-00 Gen 6 and the 01-up Gen 6?

Thanks.

Your engine is an oddball. Its not a normal "production" engine. Its based off an old style GEN 6 engine, but I am sure most will confuse it with the 8.1L GEN 7 496 truck engine. Those, have LS firing order, as well as yours I believe. You can use an LS firing order camshaft in an old school BBC . Personally, I dont care for how they sound , just my opinion though. I don't see why that Lunati cam with STD firing order, would not work in your engine.

That cam you posted, appears to be a standard 18436572 Gen 6 style big block camshaft.

HawkX66 01-13-2017 04:24 PM


Originally Posted by MILD THUNDER (Post 4519382)
Your engine is an oddball. Its not a normal "production" engine. Its based off an old style GEN 6 engine, but I am sure most will confuse it with the 8.1L GEN 7 496 truck engine. Those, have LS firing order. You can use an LS firing order camshaft in an old school BBC . Personally, I dont care for how they sound , just my opinion though.

That cam you posted, appears to be a standard 18436572 Gen 6 style big block camshaft.

Thanks for the response. So to change the firing order, it's really just a cam swap then? I've never messed around with that.
I'd rather run the 18436572 order.

Mr Maine 01-13-2017 04:49 PM


Originally Posted by HawkX66 (Post 4519385)
Thanks for the response. So to change the firing order, it's really just a cam swap then? I've never messed around with that.
I'd rather run the 18436572 order.

Cam swap and correct the plug wire location on the distributor cap. I agree that the traditional firing order sounds better.

HawkX66 01-13-2017 05:24 PM


Originally Posted by Mr Maine (Post 4519392)
Cam swap and correct the plug wire location on the distributor cap. I agree that the traditional firing order sounds better.

Beauty. Thanks a lot guys.

Mr Maine 01-13-2017 05:46 PM

Make sure it has a fuel pump lobe if you are using one

HawkX66 01-13-2017 06:47 PM


Originally Posted by Mr Maine (Post 4519418)
Make sure it has a fuel pump lobe if you are using one

That's what started me down this road. I was swapping out the cam for one with the lobe. When I measured the original cam I figured out the engine builder screwed my buddy. It was a stock rebuild instead of performance parts.

liquidlounge 01-17-2017 10:25 AM

There are some small incremental advantages with the later gen firing order. GM wouldn't have changed it on the LS motors otherwise. A couple of these advantages would be considered even more beneficial in a raw/open cooling system and carbureted V8 apps. (trying not to sound like BobM here). The updated firing order supposedly has a cooling benefit for one or both (7 and/or 8) of the rear cylinders. In addition to the more familiar "decreased crankshaft harmonics" advantage claim, carbureted V8's also see better fuel distribution, again with 7 and/or 8 seeing the main benefit. I'm just paraphrasing what my very with it engine builder explained to me over a period of 30 minutes. The sound difference can be a matter of taste; on a street car, I much prefer the sound of the LS/Ford firing order over the traditional GM sequence. On the water, most of us will only hear stock sounding 8.1's, and no, they don't sound as good as any bigger cammed GEN6 and older motor.

HawkX66 01-18-2017 08:25 AM


Originally Posted by liquidlounge (Post 4520225)
There are some small incremental advantages with the later gen firing order. GM wouldn't have changed it on the LS motors otherwise. A couple of these advantages would be considered even more beneficial in a raw/open cooling system and carbureted V8 apps. (trying not to sound like BobM here). The updated firing order supposedly has a cooling benefit for one or both (7 and/or 8) of the rear cylinders. In addition to the more familiar "decreased crankshaft harmonics" advantage claim, carbureted V8's also see better fuel distribution, again with 7 and/or 8 seeing the main benefit. I'm just paraphrasing what my very with it engine builder explained to me over a period of 30 minutes. The sound difference can be a matter of taste; on a street car, I much prefer the sound of the LS/Ford firing order over the traditional GM sequence. On the water, most of us will only hear stock sounding 8.1's, and no, they don't sound as good as any bigger cammed GEN6 and older motor.

Thanks for the info. I guess I'm too old to want to change firing orders unless there's a better reason for it. 18436572 has worked for me for better than 30 years. If the advantages were more I'd consider a change, but for my purposes I'd just rather stick with the old standard.

F-2 Speedy 01-18-2017 08:33 AM

HawkX66 ................do you have one X66 ??


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