Even if we stay with 2-stroke snowmobile drive trains, as I think we must for the near future, there could be many more engine options made available. Current SCCA legal engine choices can no longer be bought new. NOBODY, let alone the minimum needed to place an order, signed up for a 493 when Tony Murphy offered to do one last buy from ROTAX. No 494 has been used in a North American sled since 2000, nor any 493 since 2003. As I am learning in my search for a 493 with reverse, these engines are now RARE among used snowmobiles, let alone ones that have crashed to become engine donors. I studied data from the SnowSnakes web site, which allows you to sort by displacement. Among used sleds with 440-500 cc displacement, only 2 of 65 (just 3%!!) had SCCA-legal Rotax engines, one 493 and one 494. Another factor that narrows the possibilities is that some Arctic Cat 500s, e.g. 2002 legend, are fan cooled.
1) What is wrong with all the similar-displacement Arctic Cat, Polaris, Yamaha, and other Ski-Doo engines? They are all competing in the same market and must have similar performance, except for the racing models, which could be excluded from the expanded list. While I'm in rant mode, even among 493s, only the 2000 MXZ had 38 mm intakes and I have yet to find anyone who has heard of one with reverse. 2) How much difference would 40mm carbs, as in 2001-2003 Ski-Doo sleds, make? Sure, it is possible to replace the perfectly good carbs, reeds, housings, etc. for hundreds of dollars more, but it sure would be nice to start with a complete engine that has the carbs set up properly. Regards, Tony Jagodnik NER SoloII FM 6 '87 KBS Mk3 F440 [EMAIL PROTECTED] On Mar 11, 2007, at 3:40 PM, Jay Novak wrote: > Some good thoughts Marshall. > > Rubber suspension is OK if we allow longer rubbers. There are only > a few > who really know how to make the 1 X 2 rubber work & they are tough to > maintain & keep right. I think that one of the problems with F500 > is the > lap time disparity from the front to the middel or the back. I > think a lot > of this has to do with the difficulties of getting the chassis > right. I > think there might be a low cost shock that will work but it would > certainly > need a lot of investigation to make certain the costs are > managable. As I > said last winter I have a supplier ready to supply us with 3" long > rubbers, > easy to tune & adjust rates with rockers or by trimming the length. > > wide open 600cc bike engine would be extremely expensive. Some of > the most > expensive engines are F3 engines with SIR. Then you can spend > unlimited $$ > on other bits. Look at what a modern top level Vee engine costs, > now over > $7500 for a "blue printed" engine. > > 600cc will be great but we need to keep the development costs down > to ZERO. > The question is how to do this? F1000 requires stock engines. > Maybe a > specific carb for all engines with stock cams & compression a > must. Mabe an > SIR would work if EVERYTHING was STOCK. We need lots of discussion > with top > engine guys who know these engines. > > I agree weight is right at 800 to 850 lbs. > > Solid axles only are also great at keeping the costs down & they > work just > fine. > > Thanks ... Jay Novak > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of > [EMAIL PROTECTED] > Sent: Sunday, March 11, 2007 2:54 PM > To: [email protected] > Subject: Re: [F500] Class survival. > > > In a message dated 3/11/2007 1:53:29 P.M. Eastern Daylight Time, > [EMAIL PROTECTED] writes: > > <<<Let's make a list of ideas for SAVING F500.>>> > > > IMHO: > > 1) Keep the existing suspension rules. Why? Valved shocks are > expensive, > and no inexpensive 'spec' shock has proven to have a combination of > low-cost, > long life, and equal performance. The existing laptime parity > with FF has > proven that you don't need triple-adjustable $1200 shocks to go fast. > IMHO, > this is the place where a TON of money is wasted in FF/FC. > > 2) Allow a completely open 600cc 4-cylinder bike-engine option, > including > the attached geartrain. No specified engines, as the bike companies > redesign > them with a very short design life cycle. Use a mandated > restrictor box > for > all 600cc engines to equalize performance and keep the Rotaxes > competitive. > The restrictor also minimizes the impact of internal engine mods. > [Yes, I > know it doesn't completely eliminate the benefits of engine mods, > but it > drastically reduces the value for the money spent.] Why? Because > this > will give > access to a nearly limitless supply of low-cost junkyard engines and > trannies. > > 3) Keep existing 800/850 lb minimum weight. Lower weights help > keep costs > low by both reducing the need for larger, heavier (read: more > expensive) > suspension components and by reducing tire consumption. 3/8" rod > ends > should > continue to be the standard for these cars. > > 4) Keep the solid axle rule. Again, we don't need a diff to go > fast, and > this is another $1K+ item. Using a chain drive straight from the > bike > tranny > output to our existing axle designs is the cheapest solution, and > will > allow > us to keep our existing performance level. > > Thoughts? > > > > Marshall Mauney > WDC Region > 2002 Red Devil > <BR><BR><BR>**************************************<BR> AOL now > offers free > email to everyone. Find out more about what's free from AOL at > http://www.aol.com. > ________________________________ > FormulaCar Magazine - A Proud Supporter of Formula 500 > The Official Publication of Junior Formula Car Racing > Subscribe Today! www.formulacarmag.com or 519-624-2003 > _________________________________ > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.446 / Virus Database: 268.18.8/716 - Release Date: > 3/9/2007 > 6:53 PM > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.5.446 / Virus Database: 268.18.8/716 - Release Date: > 3/9/2007 > 6:53 PM ________________________________ FormulaCar Magazine - A Proud Supporter of Formula 500 The Official Publication of Junior Formula Car Racing Subscribe Today! www.formulacarmag.com or 519-624-2003 _________________________________ _______________________________________________ F500 mailing list - [email protected] To unsubscribe or change options please visit: http://f500.org/mailman/listinfo/f500 *** Please, DO NOT send unsubscribe requests to the mailing list! ***
