<html><head></head><body><div style="color:#000; background-color:#fff; font-family:verdana, helvetica, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1502453497437_11809"><span id="yui_3_16_0_ym19_1_1502453497437_11911">Hank,</span></div><div id="yui_3_16_0_ym19_1_1502453497437_11809"><span><br></span></div><div id="yui_3_16_0_ym19_1_1502453497437_11809"><span id="yui_3_16_0_ym19_1_1502453497437_11913">Captain Kittredge built three diesel subs and liked them very much. He used 7-8 hp yanmar diesels with a transmission. He highly recommended using a transmission and considered reverse a necessity. Exhaust existed at the bottom of the hull just behind a makeshift "skeg" that created cavitation (vacuum to reduce back pressure). </span></div><div id="yui_3_16_0_ym19_1_1502453497437_11809"><span><br></span></div><div id="yui_3_16_0_ym19_1_1502453497437_11809">The prop should be below center on a sub due to the low center of gravity. If you place a powerful prop as high up as the middle it will lift the stern.<br></div><div id="yui_3_16_0_ym19_1_1502453497437_11809"><span><br></span></div><div id="yui_3_16_0_ym19_1_1502453497437_11809"><span id="yui_3_16_0_ym19_1_1502453497437_12062">Greg C</span></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1502453497437_11840"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym19_1_1502453497437_11934" style="display: block;"> <div style="font-family: verdana, helvetica, sans-serif; font-size: 13px;" id="yui_3_16_0_ym19_1_1502453497437_11933"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_ym19_1_1502453497437_11932"> <div dir="ltr" id="yui_3_16_0_ym19_1_1502453497437_11931"> <font size="2" face="Arial" id="yui_3_16_0_ym19_1_1502453497437_12180"> <hr size="1" id="yui_3_16_0_ym19_1_1502453497437_12179"> <b><span style="font-weight:bold;">From:</span></b> hank pronk via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, August 10, 2017 5:14 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> [PSUBS-MAILIST] Gamma's diesel engine<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_ym19_1_1502453497437_12159"><br><div id="yiv7898430378"><div id="yui_3_16_0_ym19_1_1502453497437_12158"><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:small;" id="yui_3_16_0_ym19_1_1502453497437_12157"><div id="yui_3_16_0_ym19_1_1502453497437_12156">Hi All,</div><div id="yui_3_16_0_ym19_1_1502453497437_12173">I have just purchased a 6 hp diesel for Gamma. The plan is to use the original prop assembly that can jettison. The only thing I am not sure of is will I have cavitation problems. The prop will be about 12 inches from the occupant sphere, mounted in the centre of the sphere (equator) </div><div id="yui_3_16_0_ym19_1_1502453497437_12175">Will I have to put a spacer between the sphere and prop assembly to move it further away?</div><div id="yui_3_16_0_ym19_1_1502453497437_12161">Hank</div><div id="yui_3_16_0_ym19_1_1502453497437_12177"><br></div><div id="yui_3_16_0_ym19_1_1502453497437_12171"><br></div></div></div></div>_______________________________________________<br>Personal_Submersibles mailing list<br><a ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank" id="yui_3_16_0_ym19_1_1502453497437_12164">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br><br><br></div> </div> </div> </div></div></body></html>