Rough Stuff

[Scarabjet]

When I removed the intake grate off my PJX Volvo Jet drive, I noticed that the inside walls of the intake/suction piece are very rough. Is there any advantage to smoothing out the wall surface or it really has no effect on disturbing the water as it feeds the Cavitation Reducer & Impeller? Also, I might add that the 4.3 Volvo only puts out 225HP & it's not exactly a hot set up as most of you guys have here on this Forum (one day though...).
Thanks in advance!

[Sleek-Jet]

Yeah, but it's a Scarab Jet. You just don't see those at the lake everyday. :cool:

[BiggusJimbus]

You probably don't want a smooth surface. You get too much surface tension effect actually lowering the pump efficiency. Just a slightly rough surface will actually work better than a smooth one. Take a look at the bottom of a ski, you'll see that they are not shiny smooth. They will stick to much to the water if they are too smooth.
Smarter people may know more, but that's the way I understand it to be.
Jimbus.
[ June 12, 2003, 02:33 PM: Message edited by: BiggusJimbus ]

[Scarabjet]

Thanks! Funny you should mention the "bottom of a ski". I used to be heavy into slalom when I had my Nautique & that's exactly what prompted me to pose the question on the Forum, as I wondered if the same principle applied to the inside of the suction piece. I remember every time I bought a new ski making people cringe, as I took sandpaper to the bottom...
Rick