Re: Indy single plane 4500 manifolds - 06/24/1606:29 AM
I think AndyF has, maybe not I've dyno tested motors with both but not on the same motor I think the 3X is for large C.I. motors, probally above 511 C.I. the one motor I assembled and dyno tested the 3X was a 4.5x4.5 World block with right at 15.0 to 1 compression on race gas, it had uneven fuel distribution problems on # 2 and #7 cylinders according to the EGT and spark plugs Bob Goerge could, and can, probally fix that
Re: Indy single plane 4500 manifolds - 06/24/1603:02 PM
Originally Posted By Cab_Burge
I think AndyF has, maybe not I've dyno tested motors with both but not on the same motor I think the 3X is for large C.I. motors, probally above 511 C.I. the one motor I assembled and dyno tested the 3X was a 4.5x4.5 World block with right at 15.0 to 1 compression on race gas, it had uneven fuel distribution problems on # 2 and #7 cylinders according to the EGT and spark plugs Bob Goerge could, and can, probally fix that
Hi Cab. I believe the X manifold is more effective on larger CID engines, but Indy says it is a power booster on engines below 600cid as well as being suited for engines above that displacement.
Re: Indy single plane 4500 manifolds - 06/24/1604:31 PM
I think it depends on the cubes and power level.
I did the test years ago on a 557 with mildly ported 440-1's. This motor was only making around 725hp. I tested the 440-3, 440-3x, and 440-25 X-ram with in line 2 x 4bbl top. On that motor the 440-25 was best, by about 20hp.
The -3 and -3x were nearly identical.
A few years ago we ran a 505 with some MM ported -1's on it, 750hp range, tried the -3 vs -3x and got the same results....... No real difference.
I'd say if you're at 540+ cubes and solidly into the mid-800hp range, that's when the 3x will start to show what it can do.
The only motors I've used them on had 572-13 heads, and both of those run pretty well, but I never ran any other intake on them.
Re: Indy single plane 4500 manifolds - 06/24/1604:35 PM
Originally Posted By fast68plymouth
I think it depends on the cubes and power level.
I did the test years ago on a 557 with mildly ported 440-1's. This motor was only making around 725hp. I tested the 440-3, 440-3x, and 440-25 X-ram with in line 2 x 4bbl top. On that motor the 440-25 was best, by about 20hp.
The -3 and -3x were nearly identical.
A few years ago we ran a 505 with some MM ported -1's on it, 750hp range, tried the -3 vs -3x and got the same results....... No real difference.
I'd say if you're at 540+ cubes and solidly into the mid-800hp range, that's when the 3x will start to show what it can do.
The only motors I've used them on had 572-13 heads, and both of those run pretty well, but I never ran any other intake on them.
This application will be a 572 with 440-1 345CNC heads on alky making around 950ish hp. Just wondering if it is worth it to go to the "X" version of this intake before investing in the machine work for the injectors and port divider work.
Re: Indy single plane 4500 manifolds - 06/25/1612:03 AM
I've run them back to back on a 900 hp engine and didn't see much difference. Typically the 3X hasn't worked very well on anything I've run. I switched to a Super Victor and picked up power on my engine.
Re: Indy single plane 4500 manifolds - 06/25/1601:41 AM
From my experience the 3X is for a big HP big cube deal. Otherwise it is more plenum than smaller engines need. The 3X is pretty close to a B1 intake and treat it as such. It does not belong on a typical bracket motor especially if someone has done work to the plenum for sure. I have each ere for our drasgter