Who is running AF (alternate firing) order cams, and for how long?

[Hot COCOAL]

Just a feedback thread about the alternate firing order cams, who's running them, at what power level, for how long....

I'll be having a SoCal 6480 AF cam installed in my upcoming build and I know there are several others who will be doing the same, with many more watching and waiting, so I thought it would be a good idea to start a thread as a focal point for AF cams

Please discuss your experience

Thanks

Jason

 

[Hot COCOAL]

Some posts from a separate thread involving AF cams to get the tide goin

Thanks Rob.... I'm running one in my truck this year as well because of your success with them.

Can't wait to see the camino rock out this year with fuel on board!

Has anyone heard of anyone breaking a crank that is running a alternate firing order cam?

Not that anyone has admitted

I think our last convo with Guy was that no one has yet.... I'll be huckleberry!

Wonder how many are using alternate firing order cams. I guess the question should be who is using the cam and how is it working out. If there are only 50 of them out and we are all still in the build phase that would make sence that no one has broke a crank yet....

Good question(s)

You should start a dedicated thread asking about it

:hug:

I have run SoCal cams in both of my race cars all last season. One had the alt. firing order cam, one did not. These alt. cams run/idle the same as standard so if you like a grind, switching to an alt. firing order in the same grind will give same results.

So the engine with the alternate firing order cam after a season, no problems with the crank. The other engine with the standard cam, had a crack that showed when Fluxing.

Perfect test? Maybe not but both my SoCal race engine has the alternate firing order cams in them now.

My .02

 

[xtremebikr04]

I'm gonna be running a 9100af in my build this time around.

 

[Bigdirtylbz07]

ordering my alt firing cam from empire tomorrow for my build!:thumb:

 

[Racer]

If this sounds ignorant I will apologies up front. What is the advantage of running an alternative firing order? (The factory firing order is 1-2-7-8-4-5-6-3 and what is the alternative firing order?) On a SBC the 4-7 swap helps fuel distribution issues caused by 5-7 firing next to each other but on a DI turbo charged engine I would assume there is little gain in distribution that makes it worth doing. Thanks in advance for the information.

 

[Hot COCOAL]

If this sounds ignorant I will apologies up front. What is the advantage of running an alternative firing order? (The factory firing order is 1-2-7-8-4-5-6-3 and what is the alternative firing order?) On a SBC the 4-7 swap helps fuel distribution issues caused by 5-7 firing next to each other but on a DI turbo charged engine I would assume there is little gain in distribution that makes it worth doing. Thanks in advance for the information.

In a really crude and ignorant nutshell...
The alternate firing order cam shaft changes the harmonic frequency/order of the stress that the crankshaft sees, the duramax has been known to snap a crank or two (or 200) at all power levels including stock, and any milage, the investigative R&D and results, found that nearly all the breaks were happening in the same spot(s) behind the #1 and #4 rod journals, primarily the #1, there are and were several reasons as to why, and.....

After many years, many great minds got together and deliberated the remaining possibilities, the ending theoretical reason for the crank breakage has been determined to be harmonic stress focusing at points in the crank, due to the factory chosen firing order, the proposed solution is the Alternate Firing Order Cam.

By changing the firing order, you effectively change the harmonic frequencies, vibrations and thus the stress pattern the crank endures due to the firing order of the engine.

So far so good with the AF cams:thumb:

And that is my crude and ignorant nutshell of why/what the AF cam is for

Here's a couple threads that encompasses some/most of the material at much greater depth from the original "authors"

http://www.duramaxdiesels.com/forum/showthread.php?t=50655

http://www.duramaxdiesels.com/forum/showthread.php?t=49189&highlight=Cranks

http://www.duramaxdiesels.com/forum/showthread.php?t=50655

enjoy

 

[Ryan T]

Forum member Mikey just bought 1 from EDP and i know he did a ton of research before he made his choice maybe ask him.

 

[Hot COCOAL]

MIKEY LIKES IT:thumb:

I read a bunch of his posts too, in the end, the accumulative research involved and science behind the AF cams was enough for me to use one in my build as a optimistic "safety blanket" of sorts...with all the money in the build, it just felt right:rofl:

Dang it Ryan, taunting me with that sweet Vette in your avatar....two years in a row I've ditched a vette for the truck, last year the rear end took a crap and I decided to re gear, upgrade the LSD, lift the truck and get new wheels and tires, this year, dang near one year to the day, the engine cracks a piston and I'm building the engine sooner than I wanted....no regrets tho...well I'll do it a bit differently the next time, how bout that:roflmao:

 

[beanpole209]

Here's a stupid question... Does this new firing order make the engine sound different? Kinda like the newer 8's sound different than the old SB's.

 

[Hot COCOAL]

Here's a stupid question... Does this new firing order make the engine sound different? Kinda like the newer 8's sound different than the old SB's.

See IdahoRob's comment quoted at the end the 2nd post:hug:

 

[beanpole209]

See IdahoRob's comment quoted at the end the 2nd post:hug:

Doh, don't know how I missed that.

 

[Mikey]

1-5-6-3-4-2-7-8

would put the least twist variation on the crank. Note that the Dmax order puts the Maximum twist variation on the crank.

stock twist variation 4.33 (1-2-7-8-4-5-6-3-1)
vs
AF twist variation 2.67 (1-5-6-3-4-2-7-8-1)

As quoted by Fingers in post #149 of the thread below
http://www.duramaxdiesels.com/forum/showthread.php?t=49189&highlight=Cranks&page=10

This is a no brainer as in 1+1=2
At least as far as elementary math goes:roflmao::thumb:

I get that that the stock firing order has almost double the stress than the Aflternate Firing order
But what do I Know;
Thanks Again to Fingers and the Dmax community:thumb:

 

[moparkxracer]

Good info

That's a lot of good info

1-5-6-3-4-2-7-8

would put the least twist variation on the crank. Note that the Dmax order puts the Maximum twist variation on the crank.

stock twist variation 4.33 (1-2-7-8-4-5-6-3-1)
vs
AF twist variation 2.67 (1-5-6-3-4-2-7-8-1)

As quoted by Fingers in post #149 of the thread below
http://www.duramaxdiesels.com/forum/showthread.php?t=49189&highlight=Cranks&page=10

This is a no brainer as in 1+1=2
At least as far as elementary math goes:roflmao::thumb:

I get that that the stock firing order has almost double the stress than the Aflternate Firing order
But what do I Know;
Thanks Again to Fingers and the Dmax community:thumb:

 

[Bigdirtylbz07]

Something that I have gathered and feel free to correct me if I'm wrong but, since the last cylinder to fire is #3 then it goes #1,#2...that's 3 firing sequences all in one area in the front(where the majority of cranks break) that seems like a hell of a lot of stress and someone wasn't thinking very well when coming up with that factory firing order


Sent from a truck somewhere in the US

 

[Porno Joe]

Heres a question, I dont know if it has ever been answered before? (not meant to hijack the thread)

has anyone taken a stock engine and just done a cam swap to an alt fire cam?

 

[DMAXchris]

I wish the AF cam was available when I built my motor.

 

[Mikey]

That's a lot of good info

Yes, I am grateful for all who have done their homework and shared their answers:woott:; It sucks to spend 10-15k plus just for it to all to go boom boom.

 

[moparkxracer]

Yes

Yes it does, I'm on my second build. I'm thank full the information is passed, hope I don't have to do number 3.

Yes, I am grateful for all who have done their homework and shared their answers:woott:; It sucks to spend 10-15k plus just for it to all to go boom boom.

 

[03spoolindmax]

I'll be ordering one up here soon for my build. I'll spend the extra cash instead of having to risk damage to other parts if the crank lets go

 

[EDP]

I wish the AF cam was available when I built my motor.

Yes it does, I'm on my second build. I'm thank full the information is passed, hope I don't have to do number 3.

Unless your build was pre 2010 summer season it was available its just some where not allowed to share info for the fact of being a non supporting vendor on here and a few reasons as well. Non Related to wanting to lend a helping hand.

If anyone has any further questions feel free to ask away.