[C320-list] FW: Re: starting effort

[Karl Mielenhausen _/)]

Warren,

According to my manual, the Yanmar 3GM30's compression ratio is also 23, so that alone doesn't explain the lack of need for glow plugs. The engine is listed as having a "swirl pre-combustion chamber" for whatever that's worth.

I have the Japanese version, 3GM30FC, with fresh water cooling (ie. the closed antifreeze system). I know that the direct sea-water cooled versions have zinc anodes, but I've looked all over this engine for any sign of them and cannot find any.

If anyone has located zincs on their fresh water cooled Yanmar, please provide details of where the zincs are located.

Thanks...

Karl Mielenhausen

2000 C320 Hull#690 "Silver Lining"

New Bern, NC

http://pages.suddenlink.net/kmielen/

From: Warren Updike [mailto: wupdike at hotmail.com]

To: c320-list at catalina320.com

Date: Fri, 1 Dec 2006 16:26:15 -0500

Subject: Re: [C320-list] starting effort



According to my sources, the newer diesel engines sport a higher compression ratio and therefore don't need the assist of glow plugs.  The Perkins M30, being now likely a 15-20+ year old design, has compression ratio of 23:1 which may be lower than the Yanmar which stroke is 14% more than on the Perkins dispite only 1% larger bore.  I couldn't find the actual Yanmar compression ratio.PS it seems the 3GM does have zincs.  The 3YM apparently does not.  I think it a question of the materials used in the cooling system.Warren & Pattie UpdikeC320, #62, 1994, "Warr De Mar"Frog Mortar Creek, Middle RiverChesapeake Bay

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