Topic: Cheap to free bellmouths

[Pinhead]

I've been searching the 'net lately to find a cheap way to make or buy a bell-mouth of different sizes. I've found a few very interesting examples.

First one shows how to make them out of PVC pipe using a heat gun and a homemade form.

http://www.subwoofer-builder.com/flares-25mm.htm


The next one uses a stainless steel "eggcup" from a grocery store for a few bucks.

http://autospeed.com/cms/title_Ballistic-Bellmouths/A_110771/article.html


This one is extremely cheap and should be pretty well universally available, though it's a larger diameter. It comes from a cake dish (the kind of cake that has the big hole in the middle). You'll have to scroll about half-way down.

http://autospeed.com.au/cms/title_Building-and-Testing-an-Airbox/A_110281/article.html


If anyone else sees any examples that could be used, no matter the diameter, post up here.

[Pinhead]

Here's another way to make flares out of PVC.

http://www.burntlatke.com/rocket.html

Construction requires a technique called flaring which uses hot oil to melt the PVC.

Prepare the pipe by cutting, deburring and washing to remove anything that would cause the oil to splatter. If the pipe is washed with water, dry it completely inside and out to avoid severe oil splatter. Heating the oil is the toughest part, Bring the oil up to temperature slowly. It takes longer to cool the oil down than to heat it up so take your time. In a small pan (not your wife's or Mom's), heat about .6" of cooking oil until it will soften PVC. If the oil smokes, it is way too hot. Place one end of the pipe in the oil and hold. After about 20 seconds the PVC will begin to soften allowing you to start the bell shape flare on the bottom of the pan. Spin the pipe to achieve an even shape.

[Pinhead]

Another method to form PVC...

http://forums.justcommodores.com.au/vy-holden-commodore-2002-2004/92806-cai-alien-design.html

[mystic_1]

This method isn't as cheap as the others but metal spinning would be a very cool thing to be able to do at home.

http://www.aardvark.co.nz/pjet/spinning1.shtml







... and a tutorial from Stanford University:
http://www.stanford.edu/group/prl/documents/pdf/spinning.pdf


mystic_1

[Gorms]

Are these for velocity stacks?  How would one mount them to the carbs?

[Pinhead]

Mostly known for being used as velocity for carbs and/or intakes. If they're stainless (not plastic) they could be used in exhaust systems as well...