Bracket Talk
Mopar rb fireing order change

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October 03, 2020, 03:39 PM
Duane
Mopar rb fireing order change
I understand some Chev racers change cam for another firing order On Mopar #7 and #4 are exchange to do this. I understand benefits for this, what is the downside if any?
October 03, 2020, 03:50 PM
sr4440
quote:
Originally posted by Duane:
I understand some Chev racers change cam for another firing order On Mopar #7 and #4 are exchange to do this. I understand benefits for this, what is the downside if any?


Cost of the cam.


Joe


Without data, you’re just another guy with an opinion.
October 03, 2020, 04:04 PM
HR3377
Usually it's only 25-30 bucks and it's "supposed" to help the harmonics. There is also the LS firing order that swaps 2 & 3 also for about the same cost. Just make sure you write it down we have some 7-4 swap cams and I always have to write it down.
October 03, 2020, 09:18 PM
sr4440
quote:
Originally posted by HR3377:
Usually it's only 25-30 bucks and it's "supposed" to help the harmonics. There is also the LS firing order that swaps 2 & 3 also for about the same cost. Just make sure you write it down we have some 7-4 swap cams and I always have to write it down.


$25 more for a dodge? if this is true where do you get one? because a 4-7 and 2-3 is a custom cam for a mopar. I hope i am wrong and you can tell me go to xxxxx and get one.

Joe


Without data, you’re just another guy with an opinion.
October 04, 2020, 07:05 AM
Rick!
http://www.jonescams.com does it for the stated small price increase.
October 04, 2020, 07:06 AM
HR3377
Don't beat me up on this but I've used Herbert cams for a few builds, but yea these were chevy motors too. Just thought if they do it for them the other brands would be the same? Might be worth a phone call to them.
October 04, 2020, 10:43 AM
David Covey
Bullet. Just had a cam ground for my 572. 1.9 spread lifter bore, 7-4, 2-3 swap, used a hemi round lobe blank. Roughly 600.00. John Partridge ext 101 is their mopar guru.

Dave


"It is usually futile to try to talk facts and analysis to people who are enjoying a sense of moral superiority in their ignorance." -Thomas Sowell
October 04, 2020, 10:49 AM
David Covey
quote:
Originally posted by HR3377:
Don't beat me up on this but I've used Herbert cams for a few builds, but yea these were chevy motors too. Just thought if they do it for them the other brands would be the same? Might be worth a phone call to them.


When I ran Super Street, I ran a herbert roller. I had their cam, lifters, and springs. Ran the lifters for 10 years. Took them out because I felt guilty. Gave the cam to a buddy which he ran until I think a rod took it out. Springs were the same as the lifters, changed them because of guilt. Eventually went with Crane cam, PSI springs and unfortunately comp rollers. Rollers were biggest mistake of racing career, cost me 4 cams and lifter sets.
Dave


"It is usually futile to try to talk facts and analysis to people who are enjoying a sense of moral superiority in their ignorance." -Thomas Sowell
October 05, 2020, 12:28 PM
Al Alguire
quote:
what is the downside if any?


I have been running 4/7 and 2/3 4/7 swap BBM cams for many years. The ONLY downside is when blanks are hard to come by and the additional costs. On occasion Wedge head blanks get harderd to come by especially in 55 and 60 MM versions.


"I am not ashamed to confess I am ignorant of what I do not know."
Marcus Tullius Cicero