Re: Honda "Express"ing difficulty...

Joe Woods /
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High compression ratio heats the mix and encourages a fast air:fuel mixture burn.

If the burn is too fast, peak cylinder pressure occurs too early and heat builds up further, encouraging an even faster burn .. the end result is detonation .. a severe strain on the engine accompanied by knocking. (This is how heat puts strict limits these air-cooled engines' power outputs)

A base gasket physically raises the cylinder up. The piston can't compress the mixture as much as it would without the base gasket. So a base gasket is one of the things that determines compression ratio.

The change from a stock 40mm cylinder to 40.4 mm bore raised the compression ratio a bit.

If your combustion chamber volume is 8ccs, the rise in CR (compression ratio) went from 7.28:1 to 7:40 to 1 . This is a minor increase in CR and can be disregarded, imo..

But add no cylinder base gasket to the equation and who knows.. you might have raised CR by enough to enter the heat problem zone...

This single post is part of a larger thread. Start from the top or view this post in context.
Subject Written By Posted
  Honda "Express"ing difficulty...Topic by: James Foster James Foster 02/25/05 11:22PM
  Re: Honda "Express"ing difficulty...Re: Dan Adams (50:1) Dan Adams (50:1) 02/25/05 11:39PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/25/05 11:57PM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/26/05 12:18AM
  Re: Honda "Express"ing difficulty...Re: Jonas Quimby Jonas Quimby 02/26/05 08:17AM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/26/05 12:41AM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/26/05 10:44AM
  Re: Honda "Express"ing difficulty...Re: Jason Luther Jason Luther 02/26/05 04:58PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/26/05 05:36PM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/26/05 05:46PM
  Re: Honda "Express"ing difficulty...Re: Jonas Quimby Jonas Quimby 02/26/05 09:32PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/26/05 08:53PM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/26/05 09:42PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/26/05 11:10PM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/26/05 11:55PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/27/05 12:39AM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/27/05 08:05PM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/27/05 08:57PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/27/05 10:29PM
  Re: Honda "Express"ing difficulty...Re: Jonas Quimby Jonas Quimby 02/28/05 04:52AM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/28/05 10:44AM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/28/05 07:01PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/28/05 08:44PM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/28/05 09:02PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/28/05 11:03PM
  Re: Honda "Express"ing difficulty...Re: Joe Woods Joe Woods 02/28/05 11:21PM
  Re: Honda "Express"ing difficulty...Re: James Foster James Foster 02/28/05 11:40PM

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