R
RKT
Well-known member
I thought it may be helpful to post a little info on this engine and the large amount of "information" that surrounds this engine. I suspect it will not stay civil (it will on my part) but one can hope.
PLEASE take it as ONLY MY opinion (even though there are many other engine experts (including the manufacturers) who share this same opinion), but an opinion BACKED UP by REAL DATA (not theory or hear-say) and decades of experience
1) Rod Ratio is lacking: FACT: Polaris 800 CFI has the BEST rod ratio of any of the , modern, 800cc engines out there. The rod ratio is actually on the HIGHER end of the "acceptable" spectrum. Yes, there exists design guidelines for all engine builds.. and , again, the rod ratio of the CFI 800 is the best out there.
In short: There is absolutley no rod ratio issue. If there were, then Cat and Ski Doo would be suffering even worse. Again, opinion only , but opinion based on real data, text book design criteria, and experience.
2) There is a "Cold Shot" that causes engine failure: This is a good one and a huge gimmick.. Arctic Cat has had the SAME type as Polaris of coolant system for ever (no by pass loop) and has no issues .. the difference between Cat and Polaris is Polaris has a digital gauge so you can see the actual temps.. Cat has the same temps but no gauge.. Install a gauge on the Cat and ,SUDDENLY, it will have a Cold Shot problem as well... Only Ski Doo utilizes a by-pass loop and they only started doing this in 2000. For more details on why this is simply not an issue please check out this article:WHAT CAUSES and ENGINE to COLD SEIZE?
3) The cylinders, from Polaris, are sized wrong as delivered: This could be one of the biggest falsities of them all.. The simple fact is that the cylinders, when plated, are all plated to within .0005" of each other. This spec is a requirement and is inspected at the factory before installed on the block. RK Tek, as well as, many other Shops, have inspected a large number of these cylinders, ALL, I mean ALL, have fallen within the given spec.
Think about what kind of error it would take to have this SIMPLE inspection/operation "SLIP" by at a HUGE manufacturing facility like Polaris. Polaris has been doing this same manufacturing bore size inspection for over 50 years they are not suddenly going to quit checking cylinders or, worse yet, plate them to the wrong size.....
Not to mention.. it would be very hard for a diamond hone to NOT hone correctly.. It will always hone "round" , When the stones get worn, it will actually make the bore SMALLER not larger..
Think about what a major screw up this would be and how hard it would be for this to be "over-looked" THEN... couple that with the countless cylinders that have been measured (all in spec) and you can realize how rediculous this rumor really is..... Again, simply one person's opinion.
4) The cylinders are offset with respect to center-line of the crank.:
This is a rumor that has been surfacing for some time.. This one is 100% provable (and has been proved via video and, best yet, confirmation from Polaris direct)
In short, the Polaris cylinders are 100% pinned on centerline with the crank center-line.. There is no Offset..
Anyway, I hope this thread can stay purely informative and some information exchange can be had..
Nobody is trying to sell anybody anything... this is strictly and informative thread.
PLEASE take it as ONLY MY opinion (even though there are many other engine experts (including the manufacturers) who share this same opinion), but an opinion BACKED UP by REAL DATA (not theory or hear-say) and decades of experience
1) Rod Ratio is lacking: FACT: Polaris 800 CFI has the BEST rod ratio of any of the , modern, 800cc engines out there. The rod ratio is actually on the HIGHER end of the "acceptable" spectrum. Yes, there exists design guidelines for all engine builds.. and , again, the rod ratio of the CFI 800 is the best out there.
In short: There is absolutley no rod ratio issue. If there were, then Cat and Ski Doo would be suffering even worse. Again, opinion only , but opinion based on real data, text book design criteria, and experience.
2) There is a "Cold Shot" that causes engine failure: This is a good one and a huge gimmick.. Arctic Cat has had the SAME type as Polaris of coolant system for ever (no by pass loop) and has no issues .. the difference between Cat and Polaris is Polaris has a digital gauge so you can see the actual temps.. Cat has the same temps but no gauge.. Install a gauge on the Cat and ,SUDDENLY, it will have a Cold Shot problem as well... Only Ski Doo utilizes a by-pass loop and they only started doing this in 2000. For more details on why this is simply not an issue please check out this article:WHAT CAUSES and ENGINE to COLD SEIZE?
3) The cylinders, from Polaris, are sized wrong as delivered: This could be one of the biggest falsities of them all.. The simple fact is that the cylinders, when plated, are all plated to within .0005" of each other. This spec is a requirement and is inspected at the factory before installed on the block. RK Tek, as well as, many other Shops, have inspected a large number of these cylinders, ALL, I mean ALL, have fallen within the given spec.
Think about what kind of error it would take to have this SIMPLE inspection/operation "SLIP" by at a HUGE manufacturing facility like Polaris. Polaris has been doing this same manufacturing bore size inspection for over 50 years they are not suddenly going to quit checking cylinders or, worse yet, plate them to the wrong size.....
Not to mention.. it would be very hard for a diamond hone to NOT hone correctly.. It will always hone "round" , When the stones get worn, it will actually make the bore SMALLER not larger..
Think about what a major screw up this would be and how hard it would be for this to be "over-looked" THEN... couple that with the countless cylinders that have been measured (all in spec) and you can realize how rediculous this rumor really is..... Again, simply one person's opinion.
4) The cylinders are offset with respect to center-line of the crank.:
This is a rumor that has been surfacing for some time.. This one is 100% provable (and has been proved via video and, best yet, confirmation from Polaris direct)
In short, the Polaris cylinders are 100% pinned on centerline with the crank center-line.. There is no Offset..
Anyway, I hope this thread can stay purely informative and some information exchange can be had..
Nobody is trying to sell anybody anything... this is strictly and informative thread.
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