stock rod lenghts

[Nacho-RT74]

on BB and RB... I have had latelly a BIG confusion with LOT OF INFO I have read about that.

some RB lenghts I have found 6.768", another 6.765", some other 6.760"

definitelly what's the stock lenght ?.

I think BB is 6.358" right ?

[firefighter3931]

on BB and RB... I have had latelly a BIG confusion with LOT OF INFO I have read about that.

some RB lenghts I have found 4.768", another 4.765", some other 4.760"

whats the stock lenght ?.

I think BB is 4.358" right ?

None of those are correct.

The RB uses a 6.76 connecting rod and the B uses a 6.535 rod 


Ron

[Nacho-RT74]

sorry, just edited where I wrote 4, for the 6.

so, then 6.760 is REALLY the right lenght ?

and B is 6.535 ? 

I NEVER HAVE SEEN THAT LENGHT ON ANY PISTON LIST

http://www.beckracing.com/page40.htm

there or summit, none of them list 6.535 ?

[Nacho-RT74]

and if thats' true, then would mean the KB 240s will get more compresion that stated on some websites... INCLUDING KB ITSELF!

[firefighter3931]

Sorry Natcho....the stock B rod should be 6.35 and not 6.53 ; must be my dyslexia kicking in ! 

Some aftermarket B engine stroker kits use a 6.535in rod which is a BB chevy length....

The stock 413/426w/440 rod is indeed 6.76in long



Ron

[Nacho-RT74]

ok, dunno understand... when searching on hypereutic pistons states 6.358 but searching on forged, I find 6.535

HEY! WHY IS THAT IF WE ARE TALKING ABOUT SAME ENGINE!!!!

( I allways use KB as example because is the clearest list available )

[Nacho-RT74]

Oh ok... so then 6.358 is really the stock...

[Chatt69chgr]

6.768 stock length on RB.  The aftermarket rod lengths from folks like 440 source, SCAT, and Eagle are 6.760.  I asked guy at 440 source why the difference and he didn't know.  I think the reason is that they know you are going to have to deck the block and that at least for a aftermarket rod and piston you would want to build a zero deck configuration so they are trying to help by making the rod 8 thousands shorter.

[Nacho-RT74]

so... then we are now on the original specs I posted at first:

6.768 for RB

and

6.358 for BB

RIGHT ?

[Nacho-RT74]

6.768 stock length on RB.  The aftermarket rod lengths from folks like 440 source, SCAT, and Eagle are 6.760.  I asked guy at 440 source why the difference and he didn't know.  I think the reason is that they know you are going to have to deck the block and that at least for a aftermarket rod and piston you would want to build a zero deck configuration so they are trying to help by making the rod 8 thousands shorter.

that could sound logical, however talking about BB rods and using same logic, there is no 6.350 option

[firefighter3931]

so... then we are now on the original specs I posted at first:

6.768 for RB

and

6.358 for BB

RIGHT ?

Your "original" posted specs were 4.768/4.765/4.760 & 4.358...all of which are incorrect.

Your "edited" first post is showing more correct numbers. 


Don't get too bent out of shape for a few thousandths of rod length with the aftermarket pieces. The factory tolerances were much worse than that. 

Aftermarket pistons designed for a factory rod length will work fine with even an aftermarket replacement rod that might be a few thousandths shorter than the factory spec rod. The deck heights are adjusted during the machining and blueprinting process.



Ron

[Nacho-RT74]

mmm.. yeah, I know about tolerances, but will be fine to know anyway the original specs...

including Mopar performance... they sell 6.76 lenght RB rods, and not 6.768 what is "supposelly" the correct and exact stock lenght

DAMN MISSINFORMATION!