Looking to make a custom intake

[VooDooMotorBikes]

I wanted to make a custom intake, and I know as a fact, cold air make horsepower, so this begs the question....

Does a longer intake help or hurt these motors? I wanted to add like 10 to 14 inches and move the carb, way outta the way to some place cooler, with freshest air possible

Thanks!

 

[wayne z]

Well, carbs tend to run cool by nature. The pressure drop and atomation in the venturi lowers the air temp about 50 degrees in the carb. Ever feel one or notice condensation on the outside while the engine is running? Sometimes they ice up and affect the performance. That's why planes have carb heat control.

Now, changing to a longer intake does effect performance, normaly adds low end power.

 

[Venice Motor Bikes]

I concur; too long & any intake will ice up.
There are much better (& proven) ways of making power from these little engines... Look in the high performance section here & read about what really works the best.

 

[Texhun]

Yeah I agree with venice. And really the only gain you get from a intake pipe longer than the stock pipe is a little mid power. So you might want look into an offset intake just to see how your engine reacts.

 

[VooDooMotorBikes]

The reason I ant to do this is my carb is sitting really tight against my fame... I wanted to cut the intake, and angle it.... I thought that a Longer manifold might help.... I was looking at it again and I think I can do it by adding about 5"... I don't think that should make that much of a difference other than a nit of low end torque?

 

[Venice Motor Bikes]

You can just take a little 'pie' cut from the side of the intake, bend it & weld it back together.

 

[VooDooMotorBikes]

That wont work.... I need to add some length to the pipe... 4" sounds good

 

[bairdco]

i've found that the shorter the intake, the better.

i've built bikes with an intake only about 3/4" long and they run way faster than stock, even with match porting the stock one.

if you have to move your carb for clearance, stay away from sharp, angled bends. you want a smooth flow.

from other's experience on here with making custom, longer manifolds, it always seems to lessen power overall.

ideally, i'd like to bolt my carb straight to the engine, eliminating the manifold completely...

 

[VooDooMotorBikes]

Brilliant... That would make it fit...