Yeah but gears have higher losses than belts so more HP is lost in gears that chains and even still more than belts. Belt drive has faster response. One thing you don't mention is that racing engines use gears mainly for the timing precision but they have lower longevity than belts generally. In racing engines they get replaced often. Street engines that may go 200K miles before service get belts both for cost issues, less HP drain, and longer replacement intervals. Metal-to metal power transfers generate heat and wear. Rubber to metal doesn't. Reason Harley went from chain to belt drive was zero maintenance and less losses. Kent Gittings
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Shel Belinkoff Sent: Friday, October 05, 2001 11:46 AM To: [EMAIL PROTECTED] Subject: Re: MZ-S; Built to last Bad analogy ... Timing belts are used because they are cheaper and lighter, but are a replaceable item. They stretch and sometimes jump the sprockets, and when they break can cause problems that can destroy an engine. Timing chains, which are even stronger, will sometimes stretch and need replacement if used in a powerful engine, although their replacement interval is usually longer than the belts. They, too, have been known to jump a sprocket. Older engines, with gear driven camshafts, last indefinitely and are more precise. You'll note that racing engines generally use gear drives because they must have absolute reliability and absolute timing accuracy. Since we're talking about a "rubber" belt, my concern is that it will stretch or break after a while, causing misaligned frames or failed film transport. Gears do not have this problem, but they are more costly to manufacture and implement, which is most likely the real reason Pentax uses a belt drive. Pål Jensen wrote: > > Shel wrote: > > > More precise than what? > > More precise than 18 cogs. For the same reasing > they using timing belts on car engines. > The dataimprinting damand a precise film transport. -- Shel Belinkoff mailto:[EMAIL PROTECTED] - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org . ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ********************************************************************** - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
