Rod and Piston options for boosted 451

[747mopar]

Some of you may be familiar with my build but those who aren't it's a mild 400 with a 440 rotating assembly. I've been seriously considering adding a centrifugal supercharger to it so am looking for piston and rod options. Currently it has the complete rotating assembly from a 1971 440 (forged crank) and KB Hyperutectic pistons. My main concern is the rods and pistons but what to use?? Eagle and Scat are the 2 rods I keep coming across, for pistons I've looked at Ross and Icon. Any suggestions? Pistons will be for a 400 with 440 length rods bored .060" over and rods are just 440 rods.

Power goals will be in the 650-700hp range. I'm sure I'll get the "just do it naturally aspirated" comments so I'll explain a bit. This is a cruiser with overdrive, big cam = high cruising rpms.... mild engine with boost = happy cruising with overdrive and more ponies or at least that's the plan.

 

[dvw]

Molnar makes very nice resonably priced rod. Make sure what ever piston you use has at least .200" head thickness. With the upper ring at least .200" down as well.
Doug

 

[747mopar]

Molnar makes very nice resonably priced rod. Make sure what ever piston you use has at least .200" head thickness. With the upper ring at least .200" down as well.
Doug

Thanks, I'll look into those and check whatever pistons I go with.

 

[furryfrog]

What compression ratio are you aiming for? What is the cc size of the heads you will be using?

 

[dvw]

Thanks, I'll look into those and check whatever pistons I go with.

We sagged the center of a couple of Ross forgings in my sons turbo car. No knock against Ross, they were N/A pistons about .160" in the middle.
Doug

 

[MiradaMegaCab]

Gentleman, just an FYI, all forged pistons aren't created equally.
A 2618 alloy forging is the desirable choice for boosted applications.

 

[747mopar]

What compression ratio are you aiming for? What is the cc size of the heads you will be using?

Good question, that's something I'll have to dig into a little deeper. Talking to many boost specialist I'll be fine at 10:1 (where I'm at now) but may require water/meth injection whereas I may not if I lower the compression? Heads are 88cc.

 

[747mopar]

We sagged the center of a couple of Ross forgings in my sons turbo car. No knock against Ross, they were N/A pistons about .160" in the middle.
Doug

What kind of boost were you running? I'm hoping to keep this one reasonable.

 

[dvw]

What kind of boost were you running? I'm hoping to keep this one reasonable.

9.5-1, 360, Eddy aluminum heads, E85, carbureted, no intercooler. Have run up to 21lbs. Been 9.55@142@ 3750lbs in street trim.
Doug

 

[wyrmrider]

what's your quench and how did you get any (quench that is)
tight quench and a reverse dish works- good advice above on ring land and piston head thickness specs

 

[m79ded]

I used Ross pistons and scat H beam rods with a ground 440 grank. Very light assembly revs like a small block and needed no Malory metal to balance. Overall great combination and gobs of torque.

 

[dvw]

Quench means next to nothing in a boosted engine. Sone times it cab even be detrimental.
Doug

 

[wyrmrider]

We've run 50 pounds of boost and quench makes a big difference
What you may be referring to is the size of the quench pad- too big can be detrimental
In this case running pump gas I'd have some quench
we run some even on alky
super High octane race gas you can get away with less

 

[Hemirunner]

Some of you may be familiar with my build but those who aren't it's a mild 400 with a 440 rotating assembly. I've been seriously considering adding a centrifugal supercharger to it so am looking for piston and rod options. Currently it has the complete rotating assembly from a 1971 440 (forged crank) and KB Hyperutectic pistons. My main concern is the rods and pistons but what to use?? Eagle and Scat are the 2 rods I keep coming across, for pistons I've looked at Ross and Icon. Any suggestions? Pistons will be for a 400 with 440 length rods bored .060" over and rods are just 440 rods.

Power goals will be in the 650-700hp range. I'm sure I'll get the "just do it naturally aspirated" comments so I'll explain a bit. This is a cruiser with overdrive, big cam = high cruising rpms.... mild engine with boost = happy cruising with overdrive and more ponies or at least that's the plan.

With what you’re wanting to do, just use a good 2618 forged piston (any will be fine) and a decent H-beam rod, again any of the name brands will be fine. We’re making well over 1000 at the tire with a ross shelf piston and scat H-beams on a F2 BBC and the piston tops have been milled to below .200 thick lol. You’ll be fine.

 

[dvw]

We've run 50 pounds of boost and quench makes a big difference
What you may be referring to is the size of the quench pad- too big can be detrimental
In this case running pump gas I'd have some quench
we run some even on alky
super High octane race gas you can get away with less

What difference did it make? What combo do you run? I know new supercharged Cobra Jets don't like it. Most high end boosted stuff has been getting the flat areas of the chambers layed back for awhile now.
Doug

 

[wyrmrider]

What difference did it make? What combo do you run? I know new supercharged Cobra Jets don't like it. Most high end boosted stuff has been getting the flat areas of the chambers layed back for awhile now.
Doug

If you are referring to a 4 valve cobra jet- completely different animal
the plug down on one side is very detrimental to the BBM
The quench on a BBM two things have to be considered
One is putting two cold surfaces ( head flat place and piston)next to each other to prevent combustion (detonation)
the other is to provide some air motion
the 4 valves have been built with tumble and or swirl - even with BIG-small intakes and exhausts to get some motion
not possible with a BBM with stock type heads
Maybe some aftermarket heads have copied the Vortecs and other high swirl designs like the SBM
Look for heart shaped chambers not the wedge then check on a flow bench- if so you can get away with less quench area
so all are different