Machining Bellmouths
Since my thread on Alloy wheel repairers was so successful at getting a result, I thought I would start this one with the hope of similar results. So in the ESE thread Wobbly said that Keihin PWK Airstrikers have fences on the bottom part of the bellmouth to get better response at low throttle openings but these fences badly affected the airflow at high throttle openings (the one I am really interested in on my bucket) but since I want to keep using the PWK with it's Throttle position sensor,Solenoid Power Jet and short over all length, I did as Wobbly suggested and ground away the fences but he also said even better results could be had by reprofiling the bellmouth of the PWK to that of a PWM carb, Since I do not have a PWM to study I googled some images of PWM's and they appear to have the similar bellmouth profile to an old PJ carb I had left over from when I had a NF4 Honda RS125. Studying the PJ bellmouth it appears that either Keihin or HRC had in a lathe turned away the part of the standard dirt bike PJ bellmouth that clamps to the aircleaner rubber boot to give it a trumpet like shape over the cone like shape of the standard carb. The only way I can think of to do it would be with a CNC lathe (but if someone can suggest a way to do it on a manual lathe I am all ears) So the question is there a engineering outfit (preferably in Christchurch or surrounding area) with a CNC lathe that is able and more important willing to something like this?
A quick look on the internet suggested Mark Sutton Engineering maybe the sort of small outfit that would do this type of work, Also Automatic lathes and Arcore Engineering came up but these look like bigger outfits that maybe not be interested in this type of piece work?
Compare Pornography now to 50 years ago.
Then extrapolate 50 years into the future.
. . . That shit's Nasty.
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