4,5 bore HEMI + 4,375 crank: which length rods?

Posted By: domingo

4,5 bore HEMI + 4,375 crank: which length rods? - 03/13/11 06:54 PM

Hi!

I have a 4,5" bore HEMI cast iron Megablock and a 4,375" stroke Bryant Billet crank.

It will a naturally aspirated engine, I will use Stage V raised port exh heads and Im not sure about the intake....maybe an Indy or a used SS fabbed intake if I can get my hands on one thats not cutting edge for the class anymore...

I want to run on pump gas and try to make 900-1000 hp. (not sure if it's possible).

Which length rods do you think I should use?

Thanks

Domingo

Posted By: Cab_Burge

Re: 4,5 bore HEMI + 4,375 crank: which length rods? - 03/13/11 07:00 PM

7.1 or longer

What size are the crankshaft rod journals? If BB Chevy there are a lot of choices on brand, style and materailas for us Mopr engine lovers

The longer the rod the lighter weight the pistons will be, the lighter the piston the better the motor will rev up, and slow down

Posted By: Bob_Coomer

Re: 4,5 bore HEMI + 4,375 crank: which length rods? - 03/13/11 07:49 PM

Quote:

7.1 or longer What size are the crankshaft rod journals? If BB Chevy there are a lot of choices on brand, style and materailas for us Mopr engine lovers The longer the rod the lighter weight the pistons will be, the lighter the piston the better the motor will rev up, and slow down

With that much of a long arm stroke any shorter rods will put the piston skirts into the counter weights.

Posted By: Keith Black®

Re: 4,5 bore HEMI + 4,375 crank: which length rods? - 03/13/11 07:59 PM

Quote:

7.1 or longer What size are the crankshaft rod journals? If BB Chevy there are a lot of choices on brand, style and materailas for us Mopr engine lovers The longer the rod the lighter weight the pistons will be, the lighter the piston the better the motor will rev up, and slow down

Posted By: theman440

Re: 4,5 bore HEMI + 4,375 crank: which length rods? - 03/13/11 08:51 PM

As long as possible.

Posted By: HEMIFRED

Re: 4,5 bore HEMI + 4,375 crank: which length rods? - 03/13/11 09:25 PM

not mentioned here is that wriist pin location and comp height will determine what the right rod to match should be. Off the shelf pistons will be made for a matching length rod. I would see what piston might work without being custom made. 7.100 is the most common otherwise you might wind up with the wrong combination

Posted By: domingo

Re: 4,5 bore HEMI + 4,375 crank: which length rods? - 03/13/11 09:46 PM

Quote:

not mentioned here is that wriist pin location and comp height will determine what the right rod to match should be. Off the shelf pistons will be made for a matching length rod. I would see what piston might work without being custom made. 7.100 is the most common otherwise you might wind up with the wrong combination

Yep. My question was more along these lines...

I will check what rod journals do I have...

D