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Path: utzoo!watmath!watdcsu!rsellens
From: rsellens@watdcsu.UUCP (Rick Sellens - Mech. Eng.)
Newsgroups: net.cycle
Subject: Re: Why water cooled?
Message-ID: <1190@watdcsu.UUCP>
Date: Fri, 29-Mar-85 15:03:58 EST
Article-I.D.: watdcsu.1190
Posted: Fri Mar 29 15:03:58 1985
Date-Received: Sat, 30-Mar-85 00:28:24 EST
References: <673@rayssd.UUCP> <1144@watdcsu.UUCP> <235@vaxwaller.UUCP>
Reply-To: rsellens@watdcsu.UUCP (Rick Sellens - Mech. Eng.)
Distribution: net
Organization: U of Waterloo, Ontario
Lines: 41
Summary: 

In article <235@vaxwaller.UUCP> bob@vaxwaller.UUCP (Bob Palin) writes:

>The bikes I currently have, a 1984 VF700 Sabre and a 1980 CX500 DeLuxe,
>are both water cooled,  this is one area in which I can find no advantage,
>they both get just as hot as air cooled bikes, they're heavier and there
>is no noticable performance gain compared to similar air cooled bikes.
>
>Why water cooled ?
>
>Bob Palin,  zehntel!varian!bob


The use of fluid cooling in an engine allows the designer far better
control of the temperatures in the engine. By increasing cooling flow
in areas where the heat is causing problems, the temperature can be
locally reduced, substantially reducing wear and tear on the engine.

Also, fluid cooled engines have a much narrower operating temperature
range (once warmed up). This allows closer fit tolerances which will
increase the life of the engine and tighter tuning which could improve
emmissions and performance.

I suspect that water cooling on bikes does not generally give a net
performance improvement. ( Increased power and increased weight gives
about the same power to weight ratio. )  Small water cooled dirt bikes
are probably an exception because of the small amount of weight involved.

The big plus for water cooling is durability. Look how long Gold Wings
last, even subject to long hauls on hot summer days with the poor engine
hidden in under a fairing.

Does anyone have any ideas about increased use of the engine oil as a
cooling medium? Many bikes spray their engine oil onto the piston bottoms
for cooling. All bikes already have oil circulation systems. If these
were enlarged, and big beefy oil coolers added, we might get some of the
benefit of water cooling without as much weight penalty.

Rick Sellens
UUCP:  watmath!watdcsu!rsellens
CSNET: rsellens%watdcsu@waterloo.csnet
ARPA:  rsellens%watdcsu%waterloo.csnet@csnet-relay.arpa