I'M WORRIED ABOUT MY ROD TO STROKE RATIO.I HAVE A MERLIN SUPERBLOCK(11.625 DECK HIEGHT)THE SCRANK I HAVE IS 5.85.THE LONGEST RODS I COULD USE ARE 7.31.THE ROD TO STROKE RATIO IS 1.25.WHAT DO YOU ALL THINK.I'M TRING NOT TO WORRY BUT WOULD LOVE YOR ADVICE.PLEASE GET BACK WITH YOUR EXPERIENCES.THANKS

Old expression.... "Stuff the longest rod in that you can".

Yup. What Reed said.

isnt the std 454 and502 about 1.25 to 1? if so I wouldnt worry too much.

Max piston speed may be an issue though.

You don't have a problem unless your stroke is longer than your rod.....


Seriously- Starting at top dead center on the intake stroke, the piston accelerates downward, reaches max velocity, then slows down. The incoming air/fuel mixture starts having a problem when the piston starts to slow down.

The point at which the piston reaches max velocity is not halfway through the stroke, it is actually higher up. The point at which the piston reaches max velocity is when the crankshaft 'arm' and the connecting rod centerline are at 90 degrees. A longer rod or shorter stroke will move this point further down.

Some say that dyno tests show no major power difference. Another concern is the side thrust on the pistons- this increases with a shorter rod also. I would look into the longest rod possible.

Bulldog

Stock 454 is 1.54:1, so this is considerably worse if you are looking at it that way. I figured at 4.6 bore this is a 778 ci motor, that ought to be a monster.