this post has had me thinking a lot on this subject, IE a better firing order for our motors I take the stock firing order and write it down on two lines, four cylinders per line
1843
6578
just like the motor is normally I then swap the upper and lower cylinder numbers around and look at them to see if I can get a combination that looks better No better solutions yet I'm sure, I hope, I'm correct on this, that there is a better firing order for our motors But what is it I remember the first year I went to Pomona(1970-71 era), there was several Hemi Baracudas running in modified production classes, one that had changed the crankshaft to a 180 degree crank and the other one had a set of 180 degree headers on it. Both sounded like in line six cylinders I guess the only real way to make a better firing order is with a custom built crankshaft Anyone on here know anything they want to share with us on that Come on, open up

6 on one hand
1/2 dozen on the other..
it makes no difference...

its akin to looking down at your motor from the passenger side of the block
or
looking down at your motor from the drivers side
or theoretically turning your intake manifold and crankshaft around 180* inside the block...


it makes no difference..both pistons are in the exact same position.. just 180 apposed on cycle

again 6 of one ,1/2 dozen of the other...

cheapst

Ps..Header exhaust scavenge might be the only legitimate arguement you could make to a performance gain...

I havent seen it done on Stock type Engines.. But Most of the Highly Modified Bigger Cube Engines seem to do the 4/7 Swap..Ive seen Most of the 540 and Bigger B-1 Stuff with it, not really on the Indy 440-1 or 572-13 Stuff..The Chevys with the Big Duke and the Big Chief Heads Ive seen 4/7 done on them Most of the Time..

The SWAP comes form the Roundy-Round dirt track guys. They originally did it to try to solve the Overheating #5 & #7 cylinders issue that chevies were prone to. (Think racing with factory Blocks NOT race blocks) Some also found a few extra HP. Biggest claim I ever heard was low 20's HP. Most say mid teens on a good day.

I have heard a few people claim/state that it seems to help with High-RPM harmonics. Above 6000rpms.

From everything I have read. In drag racing it really would not be a HP advantage worth the $$$$, but would be worth the $$$$ for the longevity and durability if you are a HIGH Revver.

And yes the Factories now use the same firing order in some V-8s. LS has always had the dual swap.4/7 2/3.

I'll be doing the same whenever I get around to putting my engine together. Have to buy a Custom Cam anyways. Spend the extra few $$$ and get the swap.

I wouldn't do it just to do it.

The end result firing order on any engine is a concert between crank pin position and intake manifold Traffic.its a balance smoothing out crank harmonics by figuring out where the crank pin is in relation to cylinder firing and studying induction results with o2 readings on each cylinder,very often cross jetting figures into the end result.Most who just change to a altered firing order see little or no gain,We have found small gains with dyno data ,also sometime the temperature grid from cylinder to cylinder can be improved with the correct firing order.Last the header should be clocked to the firing order.Bill C.