["QUICK-SILVER"]

Originally Posted by 69 Limelight

Now you have 4 and 2 firing one after other. What's the difference in your theory of 5 and 7 firing one after other and robbing?

With intakes that have runner openings in the plenum, like T2 and Victor. Not only are you relocating the yank, you're adding a two one yank.

Clay

[Scott Stoneburg]

Mine has the 4-7 swap and 3-2 swap. From my understanding is all about harmonics and stress in the crank. I didnt spec the can, it came with the top end I bought.

[Formulajones]

Originally Posted by Scott Stoneburg

Mine has the 4-7 swap and 3-2 swap. From my understanding is all about harmonics and stress in the crank. I didnt spec the can, it came with the top end I bought.

bingo

And the 4-7 3-2 swap is the LS firing order. Last I checked for one of those sticks the core was $1000

[Formulajones]

Yes dad has a 4-7 swap cam in his engine, the reason was two fold but the biggest reason why was because the large lobes that Paul spec'd was only available in a 4-7 swap.

[AIR RAM]

Originally Posted by Scott Stoneburg

Mine has the 4-7 swap and 3-2 swap. From my understanding is all about harmonics and stress in the crank. I didnt spec the can, it came with the top end I bought.

Thats what I understood and the main reason I chose the 4-7 / 3-2 swap for my build. I was not sold the theory of additional power by anyone... Just smoother running through the RPM range taking stress of the rotating assembly / block trying to hold it all together.

I was originally building a Cast iron block... have sense gone with an aftermarket block and the harmonics are really not as much as a concern as with the factory block. Already have the came now.

SPEED SAFE, NICK

[Formulajones]

We've talked to guys that run dyno's and have been told they have seen no significant HP gains with the 4-7 swap in back to back testing.

However going with the full LS firing order deal has shown some HP gains according to a couple of builders I've talked to. In fact when I was looking into the LS cam cores for my BBC, Mike at Zimmerman racing told me they are worth about ~10hp give or take a couple on an engine like mine. Each engine may vary a little but that was the general consensus. I just had to decide if $1000 was worth it.