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

H

Hot COCOAL

May the farce be with you
Jun 9, 2012
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x MadMAX DIESEL said:
Half throttle at 20psi ain't cruising lol. Cruising is holding a speed, that would be accelerating hard
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what I was saying was that 20psi is "pretty much there and can be reached with ease by applying half throttle"
And yes, 20psi makes a pretty good pull

I run about 42psi max, so 20psi doesn't seem like all that much and it's right there wen I need it, takes about a second for my truck to develop that kind of boost at freeway speeds:angel:
 
S

S Phinney

Active member
Aug 15, 2008
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As Dave said , Curtis told me as well that he had seen broken cranks with AF cams and wasn't convinced enough of the benefit that hew would spend the extra money on one. He also said that if I were needed a NJ I ghee cam than stock and was looking to purchase one it was that expensive to try one for my own opinion of it. Just don't take out my already expensive bullet cam to put another expensive one in to see if it cures a problem that I don't have at the moment.

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kidturbo

kidturbo

Piston Tester
Jul 21, 2010
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Is there any other known advantages to running an alternative firing order besides improving the harmonics? Like an improved torque curve, less bearing wear or anything?

The original OEM AF swap was Ford switching the 302 to the 351W order when the new 5.0HO came out back in the 80's. History on that one I know well, new order came from Merc Marine seeing front main bearing wear and reportable some broken cranks in the Windsor from stress. Ford soon adopted the marine cam because of it's better torque profile, not it's better firing order. Rest is history, and it gave the 5.0 that unmistakable exhaust tone...

Sorry if this has been covered, just curious cause I'm one of maybe 2 marine dmax guys on here actually spinng 3k plus all day long.

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Bigdirtylbz07

Bigdirtylbz07

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it has arrived!


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Evan@InglewoodTrans

Evan@InglewoodTrans

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S Phinney said:
As Dave said , Curtis told me as well that he had seen broken cranks with AF cams and wasn't convinced enough of the benefit that hew would spend the extra money on one. He also said that if I were needed a NJ I ghee cam than stock and was looking to purchase one it was that expensive to try one for my own opinion of it. Just don't take out my already expensive bullet cam to put another expensive one in to see if it cures a problem that I don't have at the moment.

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Click to expand...

No matter how you look at it the alternate firing order cams take some load away a from a problematic area of the crank. Every little bit helps and with what it costs to build a motor the cost difference is negligible.
 
durallymax

durallymax

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Under The Hood
Hot COCOAL said:
what I was saying was that 20psi is "pretty much there and can be reached with ease by applying half throttle"
And yes, 20psi makes a pretty good pull

I run about 42psi max, so 20psi doesn't seem like all that much and it's right there wen I need it, takes about a second for my truck to develop that kind of boost at freeway speeds:angel:
Click to expand...
Bitch please, I cruise at that all day muddafockers!!! Takes some boost to keep the left lane greased.

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durallymax

durallymax

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coker6303 said:
42psi at 1300rpm is cranking out some torque!! lol :thumb:
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Yep, the twin turbo ACERT kitties like 1250-1500. This one's just a little guy 1650ft-lb. It runs 50psi tops. Place I used to work had a chipped 550hp C15 and it would run 72psi.

The ACERT runs kind of like a Miller cycle engine. It uses variable valve timing to hold the valve open until the piston is up a little ways. This is why it needs a lot of boost down low. Other older single turbo motors run 25-30psi stock.

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derrickmanx1

derrickmanx1

I'm that guy
Dec 30, 2010
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central texas
I just wasted alot of time reading about complaining about this and that and no facts about the cam. Could someone set aside their BS and answer the question. I'm starting a build and would like to know if it's worth the trouble or not.
 
BHoward6.6

BHoward6.6

West Coast
Feb 9, 2011
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derrickmanx1 said:
I just wasted alot of time reading about complaining about this and that and no facts about the cam. Could someone set aside their BS and answer the question. I'm starting a build and would like to know if it's worth the trouble or not.
Click to expand...

I'll answer your question, yes the AF cam is 100% worth the time, effort, trouble. All BS set aside.
 
Trippin

Trippin

SoCal Diesel
Aug 10, 2006
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I'm not sure what facts your looking for...........

1) The fact that the factory firing order ends with cylinder # 3 and is followed by cylinder # 1 and 2. The crank breaks 95% of the time before the second main journal or immediately following it, which indicates there is a lot of flex going on in that area.

2) The fact that in certain High HP applications we were virtually guaranteed a cracked or broken crankshaft after a season of competition, this occurred for many years. By changing the firing order we have not broken one since.

3) The fact that an AF cam will cure erectile dysfunction. Because besting your competition time and time again with out breaking a crank is a guaranteed woody? :D

:hug:
 
Evan@InglewoodTrans

Evan@InglewoodTrans

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Trippin said:
I'm not sure what facts your looking for...........

1) The fact that the factory firing order ends with cylinder # 3 and is followed by cylinder # 1 and 2. The crank breaks 95% of the time before the second main journal or immediately following it, which indicates there is a lot of flex going on in that area.

2) The fact that in certain High HP applications we were virtually guaranteed a cracked or broken crankshaft after a season of competition, this occurred for many years. By changing the firing order we have not broken one since.

3) The fact that an AF cam will cure erectile dysfunction. Because besting your competition time and time again with out breaking a crank is a guaranteed woody? :D

:hug:
Click to expand...


#3 is going to seal the deal for a lot of the older folks on here. Mike L might buy one just to put in his back seat.
 
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