Help me pick a gear for my combo
So small blocks need more gear huh......
help me understand this. so if I have 340 putting out 450hp/400tq, it will need more gear than a small big block putting out the same numbers?
OK, I'll bite.
Depending on your performance goal, yes.
To use your example, a 450 hp 340 (3.31 stroke) generally won't start making big power (overcoming inertia) until the engine reaches a higher rpm. 450 hp from a 340 is pretty stout. That's going to take a pretty sizable cam that probably has an operating range above 3,000 rpm. What happens below that? You need torque multiplication, i.e. gears.
The amount of torque big blocks can produce at a lower rpm is
generally going to be greater than what the small block can produce at the same rpm. That's engine architecture and essentially volume, nothing else. If you stroke a 360 to 400+ inches, then you start reaping the benefits of more torque at a lower rpm. That's not to say that big blocks won't rpm or small blocks have no torque but that's the general idea.
The torque multiplication that the steeper gears create helps to overcome inertia more efficiently, there's less parasitic driveline loss trying to get the car moving. The O.P. has a street machine 318 based engine which still has a small bore. Needs gears.
So yeah, I guess all the NHRA 340 stockers in the 10s that use 5.38 gears are doing it wrong. Those cars are not streetable because of the combo. High stall converters, low gears in the trans and super steep gears to take advantage of whatever torque multiplication they can harness. Those combos are proven to work.
