Flywheels

[FearThe4Doors]

Why are there different diameter flywheels?

for example, i just found out my 3.9L 5 spd dakota has a 14" one, where older SB's have 12" ones

[Dart]

First of all yours is a truck and they genrally put a little bigger clutch in the truck. Some of the early 273s were tiny (10.5") so I don't know that anyone would be able to answer why they did this.

[FearThe4Doors]

larger/heavier vehicle... bigger flywheel to keep the engines momentum going and prevent from stalling... makes sense to me if thats why

[dave571]

The bigger clutch also spreads the load out on apply, better heat dissipation.

Bigger clutch, better for more work.

[Tarrbabe]

Bigger clutch means that if a pressure plate puts out 1500 lbs or even 50,000 lbs pressure (whatever it is rated at), it puts it out over a bigger surface area. Thus much better grip over a longer time. More HP? Better grip! Remeber, that 10" or 11" or even 14" is applied at the rate of 3.14159 or so.

[FearThe4Doors]

the strange thing is.. even though the actual flywheel is the 14"... the clutch disc doesnt even go out much past the half way point. There's LOTS of unusued flywheel surface. Its almost like they just made it bigger for more weight or heat dispersion.