Flange mount air horns vs. throat questions

[Tyler]

I tried searching for an answer on here and through google and I couldn't find much about it. I've been looking for velocity stacks now and was recommended pierce manifolds. They have two styles available with two very different prices.

 

What are the pros and cons of flange mount versus the insert type? The one that mounts outside is almost half the price.

 

Flange Mount

 

Insert Mount

 

 

Thanks!

[brokebolt]

The insert type you will still need the "tabs" that hold the horn in place; two should be used per horn, four per carb. Extra cost not addressed in the original post. The flange mounted version will fit any side draft, Mikuni/Solex, Weber, Dellorto, or O.E.R., etc. Because of the "universal" fit, you will see most air horns are of this type. The insert type will be a smoother transition from the horn into the inner venture (auxiliary venture). Mikuni/Solex did this with an insert that fit over the inner venture and butted up to the outer venture (choke). Honestly, I really don't see that your going to "gain" that much performance using the insert type vs. the flange type. Horn length and horn shape play a much bigger role then insert of flange mounting in my humble opinion. Longer horn is like a longer manifold, better for street use. Wide opening on the horn is better for air draw. A rolled lip at the horn inlet seems to the the accepted superior design or a donut ring on the horn inlet...if that makes sense.

 

Honestly, this is why I prefer the Dellorto carb. The inner venture has the insert that the Mikuni/Solex units had in two pieces, slap on a horn and your golden. Also, no gasket for the Dellorto carb on the auxiliary venture. Try changing the choke while the carb is still mounted on the manifold, and attached to the engine in the engine bay. Not that fast and not that easy. Just my rant of the day!!! (And yes, I know Weber didn't use a gasket.)

 

Factor in the tabs, recalculate and then compare cost vs. performance. Either version should bolt on and work. Hope this helps. Happy wrenchin'!

Edited June 27, 2010 by brokebolt