Subject: Bell mouths
From: ACRE
Date: 3/7/2005, 5:10 PM


Paul wrote:
We are about to go into mass production with this aluminum
bell
mouth.
Fits 2 inch OD tubes with .0625 wall. Can be epoxied on or tig
tack welded. No price yet. We are still looking for a
distributor.

Paul Lamar


Mark wrote:
What are the design critia for bell mouths. I assume any
radius
helps, but there seems to be a wide range of shapes out there from
little circular radius bellmouths like these to larger more
gradual and epilliptical ones. When I made a set for Brian
Trubee, I
just took the dimensions he wanted and modified from circular to
elliptical because it seemed more logical from an airflow
perspective. It was a fun project, but way too much work on a
little
7X chinese lathe CNC conversion. Made heaps of swarf :)

http://www.wrathall.com/Images/Bellmouth.jpg

I would guess this topic much have been explored at great
depth by
the racing community. May be Archie has a definative word for us?

Regards,
Mark

Those are beautiful Mark. How much money do you charge?

Do they fit 2 inch OD .065 wall tubing?

How does one fasten them to the tube?

Paul Lamar


Their were two with 42mm ID and two with 47mm ID. There is a step
to
slip over the tube OD, and they could be bonded, but I think Brian
welded them (Right brian?)

Sorry Paul, This was the first complex shape I had done on my
lathe, and
it showed me that that the lathe is just too small for it. The spindle
only has 250w, so to core out 47mm you end up doing a
couple of hundered cuts with the boring bar.

I would estimate I put 200 hours in to get the four bell mouths
for
Brian. I really don't want to do any more. On a real CNC lathe, this
would be a very simple quick part (although not very
efficient - you should really start with a casting).

Mark


Keith Moore wrote:

Paul:

I made half inch radius bell mouths in aluminum with a carbide router
bit ($35 at Home Depot), and a table mounted router.  The bit mounts a
small bearing at the end to locate the ID of the inlet.

The aluminum cuts easily with light hand control.

Matt Prather wrote:

Seems like this might be a good application for injection molded
plastic.   Polished Al or Stainless looks pretty, but otherwise, I
can't see the benefit of metal.  This isn't exactly a high temp environment,
even when turbocharged.  It strikes me that one of the vehicles that
I have owned recently had a bell mouth on the intake for some reason.
I'll see if I can find it and see if the diameter is right.

Regards,

Matt-

 
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