So I'm looking to buy an intake manifold for a 45 DCOE and I see there are two designs, the shorty straight one that puts the carb on the side of the motor, and the wrap-around one that puts the carb on top of the motor.

Which is better? I would think the straight one would be more efficient since it's not trying to turn the air/fuel 180 degrees, but then the wrap-around would keep things cooler since it isn't holding the carb above the exhaust manifold. What's everyone's thoughts?

 

the wrap around is better, it increases torque and it does cool the air /fuel mixture

 

wrap around (side draft) has longer intake runners and is better for lower end torque.

straight (down draft) is better for high hp, all out power because of short intake runners.

both of these are due to harmonic wave tuning just like exhaust systems. If the intake port is open at the time that a positive pressure wave is approaching it, it increases the amount of air/fuel that the combustion chamber recieves. Do a search you should find lots of info.

-Marques

 

I'm not talking about downdraft vs. side draft...

The short straight side draft manifold, is that what they call the "Lake Cities" style? I did a search on the matter and only came up with mostly random stuff.

Couldn't you simulate the longer intake runners of the wrap-around style by using longer velocity stacks on the carburetor w/ the short straight manifold?

I haven't made up my mind which I want yet, just trying to get a pros/cons list of each. Any more thoughts, anyone?

 

Send a pm to drivefast7. he is using lakecities with dellorto.

 

Thanks, I'll PM drivefast7...

Is there anyone here who's had experience w/ both? I understand that the longer runners on the wrap-around will provide increased lower-end torque, and the short straight shot of the Lake Cities type will provide better high-end horsepower gains... but will the LC shorty w/ a 45 DCOE actually give me worse torque than my stock Nikki setup?