LongJohn1980
Member
Just wanted to see what some of you think about trying the firing order swap on a 409? I had a prominent engine builder suggest doing this on a small block build for my 63 nova. He told me most cam companies will do the custom grinds for the swap. Here's the article I came across today from HOT ROD mag.
"A typical Chevy firing order is 1-8-4-3-6-5-7-2. For the vast majority of applications, this firing order works nicely and there’s probably no need to change it. But in a race application, there are various firing orders that can effectively improve power and reliability in an engine. Typically, there are seven other firing order arrangements which can be used without changing the crankshaft layout on a Chevrolet V8. These firing orders include the following:
1-8-4-2-6-5-7-3
1-8-7-2-6-5-4-3
1-8-7-3-6-5-4-2
1-5-4-3-6-8-7-2
1-5-7-3-6-8-4-2
1-5-7-2-6-8-4-3
1-5-4-2-6-8-7-3
Reher-Morrison has tested the various combinations and found some interesting results. When the firing order is revised to 1-8-7-3-6-5-4-2, you’ll find some power and reliability. Now, if you race a Pro Stock car, this is no secret since the revised order has been in vogue for some time. With the revised firing order, fuel distribution dilemmas are resolved. The engine tends to run cooler, and perhaps just as important, the engine is actually smoother. How much extra power is there? Anywhere between 8 to 10 measurable horsepower. There was once a caveat here though: The average enthusiast couldn’t easily get a cam with the revised lobe positions, but not so today. Reher-Morrison sells such a package (called Big Stick Cams) for Chevy big block/Big Chief head combinations."
Sounds like some could benefit from the cooler engine, plus who dosen't like a few extra ponies!
"A typical Chevy firing order is 1-8-4-3-6-5-7-2. For the vast majority of applications, this firing order works nicely and there’s probably no need to change it. But in a race application, there are various firing orders that can effectively improve power and reliability in an engine. Typically, there are seven other firing order arrangements which can be used without changing the crankshaft layout on a Chevrolet V8. These firing orders include the following:
1-8-4-2-6-5-7-3
1-8-7-2-6-5-4-3
1-8-7-3-6-5-4-2
1-5-4-3-6-8-7-2
1-5-7-3-6-8-4-2
1-5-7-2-6-8-4-3
1-5-4-2-6-8-7-3
Reher-Morrison has tested the various combinations and found some interesting results. When the firing order is revised to 1-8-7-3-6-5-4-2, you’ll find some power and reliability. Now, if you race a Pro Stock car, this is no secret since the revised order has been in vogue for some time. With the revised firing order, fuel distribution dilemmas are resolved. The engine tends to run cooler, and perhaps just as important, the engine is actually smoother. How much extra power is there? Anywhere between 8 to 10 measurable horsepower. There was once a caveat here though: The average enthusiast couldn’t easily get a cam with the revised lobe positions, but not so today. Reher-Morrison sells such a package (called Big Stick Cams) for Chevy big block/Big Chief head combinations."
Sounds like some could benefit from the cooler engine, plus who dosen't like a few extra ponies!