440 hp rotating assemble mismatch questions?????

[DoubleDlover]

Ok so you have the 908 6 pack rods. crank. balancer and flywheel/converter.... questions are... Is there really a difference between a stock forged crank and a hp one?? If you replace the hp rods with just standard ones can you still run the hp balancer and flywheel or will that f*** everything up??? I think thats it for now. thank you for any input.

[70 sublime]

The six pack rods need the heavier balancer so I would think it would screw things up if you swaped the rods for the lighter ones without swaping the balancer also

[Challenger340]

Get it Balanced

[b5blue]

  My understanding is connecting rods for forged crank are matched to balancer so 6pk rods require balancer with extra weight and that balancer can't be used with standard connecting rods.     

[John_Kunkel]

Get it Balanced

Or just use a neutral balanced balancer and flywheel/converter. Supposedly, the only difference in the 6-Pack crank is the strengthening process which doesn't affect balance.

[BSB67]

Get it Balanced

Or just use a neutral balanced balancer and flywheel/converter. Supposedly, the only difference in the 6-Pack crank is the strengthening process which doesn't affect balance.

The OPs question is unclear, but believe John is close to understanding it. 

Things like "hp balancer" doesn't make sense as there are two or three different balancers on hp engines.  Maybe he means neutral balanced???

[DoubleDlover]

bsb67... OK tell me about the 3 different balancers on a 70 hp 440 engine..

[b5blue]

https://www.440source.com/blockinfo.htm     (Bookmark this link instead.) 

[John_Kunkel]

bsb67... OK tell me about the 3 different balancers on a 70 hp 440 engine..

He said HP engines, not '70 specific.

'66-'69 neutral balanced, forged crank, asymmetric pulley bolt pattern

'70-'71 external balanced, forged crank, asymmetric pulley bolt pattern

'72-'78 neutral balanced, forged crank, symmetric bolt pattern

'73-'78 external balanced, cast crank, symmetric bolt pattern

[b5blue]

The HD rods used in 70-71 while not exclusive to just 6BBL were not universal to HP so 66-69 could continue to 70-71 is my understanding? 

[John_Kunkel]

It wasn't just the heavy rods that made external balance necessary in '70-'71, but the combined weight of the pistons/rods. Ironically, all of the heavy rod 440's after '71 didn't need external balance because the lighter low-compression pistons made it unnecessary.

[b5blue]

Thanks!