While searching for a camshaft I have come accross cams that change the #4 and #7 firing order. Can anyone explain this to me, why would you do this?

 

ok I found a little bit of an answer,

"The 4/7 firing order SWAP configuration decreases crankshaft deflection, delivers a smoother torque curve, and aids acceleration. 4/7 SWAP camshafts also provide an incremental horsepower gain in the engine. 4/7 SWAPS were track tested in a wide variety of applications and all results were improvements over the standard firing order. Dyno results have shown a 3 to 12 HP gain with the SWAP. The only change that must be made to the engine is to swap the 4 and 7 plug wires to reflect the alternate firing sequence. 4/7 SWAP cams are available in most popular grinds and on custom ground camshafts."


Now my question is Has anyone used one of these??

 

Sure do, check out the new chevy 8100 series big block. I know that is one of many of the new engines out there. When that 496 c.i. idles, you cant see it move because of the new fireing order. Alot of racers get that cam grind, and has been around forever. ASk your local machine shop, htey have problem done many of them. It is good for a few hp in a correctly built engine.

 

and it seems to me that is not all you change. I am pretty sure you have to set the crank, rods pistons up a littel different. I almost used this grind, but knowing me, i woulda forgot the firing order on my tune up.. ha ha.. stupid teenagers

 

No, everything else should be the same.

 

So your saying it will also cam the idle slightly? For instance, maybe make a cam sound like it has slightly less duration?

I know the 5L mustangs sound way different because they have a different firing order, Ill have to look theirs up..