Polaris 800 owners DON'T replace your stock Pistons

I know since 2008 the Polairs 800 Small block has cause a flurry of this question...............

When should I replace my Pistons or top end ?

And if I do who's Pistons should I use ?

Indy Specialties advice is as follows.

If it runs perfect, and has the same power, and holds the exact same RPM as it did when it was new ( DON'T TOUCH IT ) I don't care how many miles are on it.

If performance is down ( FIRST AND FOREMOST ) Make sure your drive clutch is in good condition, your belt is in good condition, and the driven clutch is adjusted so the sled has the correct belt deflection.

If you get your a$$ handed to you by another sled on the same make & model your first move should NOT be replacing the Pistons.....

If you have not address ( THE FIRST & FOREMOST ) questions you have reason to touch the motor !

I have been building Polaris motors for over 30 years and I can promise you one thing for sure.....

More 2008 thru 2017 Polaris 800 motors have failed because of premature piston replacement with an aftermarket piston.

Indy Specialty sells more OEM Pistons and top end kits to people that just got done doing a fresh piston replacement and didn't make it 500 miles then any stock OEM original Pistons. ( my motors included until 10/15/2015 ) * poor honing procedures ruin everything.

My list of questions when we get the call goes as follows.......

1-was the motor running when freshened it up ? Most often ( Yes )

2-were the Pistons that came out stock OEM ? Most often ( Yes )

3-how did they look ? Most often ( they looked great )

4-how many miles were on it ? Range 1000 to 12,500 miles ( yes a few customers have had over 12,000 miles the stock OEM Pistons ( all have Been dragons )

5-my next question is...... After you answered questions 1 thru 4 do you really need to ask me what Pistons I recommend for your Polaris motor....

To finish off the with one last promise....

If you take 90 used Polaris 800 sleds....

That's 9 groups of 10 sleds model year 2008 thru 2017

These 9 groups of 10 sleds all get a fresh rebuilds

All get brand new OEM cylinders.

Group 1 - cast OEM Polaris factory Pistons
Group 2 - cast SPI factory import copy
Group 3 - cast SPX factory import copy
Group 4 - cast Kimpex factory import copy
Group 5 - cast OEM Arctic 800 converted for Polaris
Group 6 - cast prox factory copy
Group 7- domestic forged wiseco
Group 8- international import forged Woosner
Group 9- cat domestic forged wiseco converted for Polaris
Believe it or not there more options I have not listed.

Ok we 90 fresh rebuilt sleds with Brand new OEM cylinders.

They all get parked outside in a row for 5 days at ZERO degrees Fahrenheit

They all get started at the same time and are allowed to idle until water temp hits 70 degrees and at that moment they are all held wide open for 1 mile.

Group 1 thru 6 will all mostly likely make it ( why I say mostly likely ) I have not personally run.... Cast Kimpex, cast SPX, cast cat OEM, cast cat copy.

Group 7,8,&9 will all lock the motor before the 1/2 miles mark... The Cat copy forged will not make the it past the 1/4 mark.

How do I know this you may ask..... The factory Polaris cast OEM piston 2008 thru 2017 has over .008 thou more taper from bottom to top then any of the other non-Polaris copies......

The SPX,SPI,PROX Polaris copies have close to the same taper..

All the other Pistons forged or cast are close to .008 bigger at the top then
OEM Polaris Pistons.

( there is a chance the cat OEM & OEM copy won't make the mile mark but they will go far past the forged.

Why ? Simple......it's a mono block with a very narrow center to center 128mm....... ( poor water flow around the exhaust port ) holds a bunch of heat on the front of the piston.

The simple reason turbo applications tuned properly piston life is over double a normally aspirated motors...... The turbo pushes air thru the motor keeps the heat moving.

Polaris Pistons are the most expensive with almost ( NO MARGINE for profit )

That why no one wants to sell them.

Poor plated honing procedures & poor cylinder finish has been the main reason for factory OEM failures of the past. ( the factory OEM finish across the industry has gotten so much better. ) I once thought impossible to match of beat. HG7 if to date the best i personally have seen.

( Of which Indy Specialty was Quilty of from 2005 till Oct 14th 2015 )

All the theories on cast iron cylinder honing do not apply to plated cylinders. * ( The smoother the better. ) ZERO cross hatch needed ) *

I believe if you are selling engine rebuild services to any customers with plated cylinders with cylinder mounted EFI systems you better have invested a minimum of $50,000 yo $150,000 in updated equipment so you can give customer a cylinder finish to at least as good as the factory finish with the goal to be better then the factory.

The EFI plated cylinder Polaris has brought on a steep learning curve for a lot of us.

This is the reason we offered all previous customers pre-October 15th 2015
Free updated HG7 cylinder finish with a No charge 1 year extension added on to your warranty.

Thanks to all Indy Specialty customers for your business !

Dan

Mr. Dan. Can I ask you a couple of questions about pistons and bores?

First. If you heat soak to a minimum of 100 degrees before starting to apply any major throttle does the forged piston fit OK then?
I'm one of those that replaced perfectly good OEM pistons at the time. Barrels measured great for taper but chamfers were poor and ruined the original layered rings.
In particular I am refering to the MNTKT kit Wiesco pistons which have shown no signs of weird wear or leakage yet.
I'm sure you have seen them all lol.

Second. Your HG7 hone. If a barrel is true, is there enough coating originally for this to be done without a replate or is this applied only with a new "replate"?

I'm gonna try for some more info lol. This is about the bottom end which you may have seen a few of lol.

If you owned a Fuji cranked 800 and slobbered it with oil (I mean dripping out the exhaust at the end of any day) since hour one, never blew a belt or any other catastrophe, measures OK on the ends, would you be concerned approaching 5000 mountain miles?

Thanx if you get the time.

Thoughtful Presentation.

Moderators note:

Thank you, sincerely, Dan... for taking your time to make your case and detail your presentation/opinion. It is always great to have this kind of thoughtful input here on the forums.

There are many out there that use some of the products and kits that are referenced in the first post above...

REMEMBER... This is Dan's presentation of the way he sees things... you neither have to defend your product nor bash Dans presentation here....That gets us no where.

I really don't want to see a Brand "Flame war" going on here in this thread.

If you want to present an opinion contrary to the one presented here... please feel free to start your own thread and present what you feel are the strengths of your product or product of choice.





.

I agree with Dan on this. The Polaris factory piston is great quality vs others that say there better?
The only thing Polaris needs to do is lose some piston weight.
I have the answer with titanium wrist pins .

The honing procedure Dan speaks of? Some great race shops do it properly while others don't

There is so much misinformation on the internet about Polaris motors and pistons it's not funny

Thank you Eric ! I don't and didn't mean to slam anyone products.

The posts is directed at past customers with old motors from Indy Specialty that had HG3 or HG5 subpar cylinder finish.

And to help with what seems to be mass piston confusion on a really great mountain sleds.( I am not in business to sell Pistons )

geo said:

Mr. Dan. Can I ask you a couple of questions about pistons and bores?

First. If you heat soak to a minimum of 100 degrees before starting to apply any major throttle does the forged piston fit OK then?
I'm one of those that replaced perfectly good OEM pistons at the time. Barrels measured great for taper but chamfers were poor and ruined the original layered rings.
In particular I am refering to the MNTKT kit Wiesco pistons which have shown no signs of weird wear or leakage yet.
I'm sure you have seen them all lol.

Second. Your HG7 hone. If a barrel is true, is there enough coating originally for this to be done without a replate or is this applied only with a new "replate"?

Click to expand...

Hello geo.

Morning heat soaking is vital to long engine life.

Rings losing their life early is simply caused by a cylinder finish that to aggressive..... If you choose to install new Pistons ( if the rings are bad it needs Pistons because the skirts are woren ) if the cylinder finish took out the rings then it's wearing material off the skirt creating to much clearance.

If you replace the Pistons into your stock OEM cylinder ( DO NOT HONE IT )
I know it seems wrong but it's not....convention old fashion cast iron bore thinking does not apply. Believe it or not the first set of rings and Pistons still have not woren the cylinder as smooth as it needs to be.

HG7 finish that we polish into the cylinder takes about a 1 hour procedure to achieve those results. ( the procedure removes a maximum of .0005 thou ) that's 5 tenths of a thou or 1/2 thousands.

A cat wiseco ( if that's what you are running ? is a dangerous piston with a close to factory spec cylinder if the motor gets cooled down ) The cat wiseco is about .008 bigger then the OEM Polaris piston at the top..... anytime you have a forged that's bigger in the area that expands the most the piston is very prone to 4 corner seizing if it sits parked with the snow packed in the tunnel up against the coolers......

Then you start it........ The motor is hot the thermostat is open and the hot water leaves and the cold water from the coolers fills the motor and the thermostat closes and now the cylinder shrunk and reduced in size by a few thou......

Then heaven forbid your in a really bad hole and you have a long pull to get out and the motor is going to be pin WOT for a long time with ice cold water in it with cold cylinders .....

Heat soaking doesn't do anything for this..... Heat soaking helps warm the crankshaft up..... Cold water shrinks everything that has a water passage.

Don't get me wrong, you can get a set of wisecos to survive in a small block
But a big cylinder helps ( like bore size 3.349 )

With HG7 finish & a Polaris OEM piston I would not be afraid to send out a cylinder at bird size 3.345


There is plenty of plating, Hg7 only takes .0005 tenths from a fresh plated cylinder..... A used cylinder normally only takes a few tenths to polish.

But in the torque fixture We like to just touch them with fine cutting abrasive before we move to polishing.

Dan

Ratchit said:

I agree with Dan on this. The Polaris factory piston is great quality vs others that say there better?
The only thing Polaris needs to do is lose some piston weight.
I have the answer with titanium wrist pins .

The honing procedure Dan speaks of? Some great race shops do it properly while others don't

There is so much misinformation on the internet about Polaris motors and pistons it's not funny

Click to expand...

Yes they are heavy, and one of the reasons they are so heavy is the massive
Gussets they use from the wrist pin boss to the skirt.

Titanium wrist pins, Hmmmm.......interesting

Dan,
Glad to have you back on SW.

TRS said:

Dan,
Glad to have you back on SW.

Click to expand...

Hey Tony ! Thank you

Had this all typed for the piston thread but it was to long and wouldn't post.

So I will put it here.

Title - WARNING PROX POLARIS 800 SMALL BLOCK PISTONS.

There are many options out there and research is a must.

I want to share a bit of info I came up with regarding the new ProX Piston for the 800 Polaris small block.

Unfortunately I purchased a few hundred of these Pistons last year & the year before to give customers a less expensive alteritive into a cast OE copy....... BIG MISTAKE !!

To get the record straight ( ProX ART Japan ) Pistons are a completely different animal then the Wiseco purchased ProX....... The ProX sold under Wiseco is a piston that was built supposedly from the tooling bought from ART Japan then taken to Twain to be reproduced to supposedly the same specs. NO NO NO !!! Nice try not even close.

If you look really close at a OEM Polaris 800 small block piston, you will notice that the top ring locator ( anti-rotation pin ) is intentionally installed at a downward angle.

SPI/SPX has copied this tactic from Polaris and it is an absolute requirement..... This tactic keeps the inside or bottom location of the pin locator down and away from the intense combustion camber heat and makes the ring locator much more dependable.

The ProX OE copy piston has a ring locator that is install 90 degrees to the ring groove and it also to short......

I called Wiseco and spent extensive time with one of their engineers explaining the problem...

Before I got to the engineer you know what the standard big corporate line was.....

Quote - ( we have not had any complaints before and have had no problems with those Pistons)

Quote - ( you are the first person to call )

Mind you this call was about a year after I stopped selling the ( I was to damn busy warranting trashed cylinders and giving away $430 OE piston sets to replace the And new cylinders.

Keep in mind No where does Indy Specialty claim to warranty Pistons......but I have warranties hundreds of them with OE replacements at over 3 times dealer cost price.

I also informed Wiesco I would be informing the public of this problem to force them into addressing it.......

After they told me the standard cooperate line...... I said the reason after market piston buyers rarely call is because they know they don't have a chance in he!l to get help..... Plus no single person or small shop ever buys enough volume to see them problem...

Plus no shops in the sled Industry other then Indy Specialty offer a 3 year written warranty in a complete motor..

Big warranties make you find weakness and they make you correct it at a feverish pace.

There is a lot of ProX Polaris 800 product on the shelves that should be recalled...... ( it will never happen )

The consumer will help to clear the shelf of the defective batch and I am here to help slow it down.

Dan

I am having flash backs of the 90's with your long post and good info ...... Hahahaha. Good work!!!!

Awesome Dan! Always insightful, and sharing your info and findings through tons of research, testing, trial and error... You're a huge asset to our sport!!!

I love reading your posts.

Hi Dan,


Thanks for the post. It's great to have you on here. And thank you for the order a couple weeks ago. Jon spelled my last name wrong LOL.

I only have experience with one aftermarket piston for the 800 CFI and that would be the one that comes in the MTNTK Fix Kit which is the taller Weisco piston and uses the cylinder shim.

I'm curious if any of the findings you are seeing are with this particular piston OR are with the direct copy of the stock piston?

The reason I ask is because I have installed approximately 35 of these kits with zero comebacks, 4 corner seizes, issue's, runnability issues, etc. since they came out in 2010ish. Some of them have been installed (with my perfection attention to detail) with your gusseted cylinders, other's just R&R'd, and some with brand new mono's, even with the 08-09 thin cylinders. I could not work on these my way paid by flat rate time.

In fact, I like this kit so much I was telling Justin I was going to ask you to build me a Longrod and shim that will allow me to run the MTNTK Fix Kit this summer.

As for your results, I completely understand your sample size and mine are different and could be explain some of the reason why we are seeing different results (if we're comparing results from the same piston). I also have to question the ability of some of the installer's, condition of the rest of the motor, not having the right tools, drinking alcohol during assy. and a multitude of other factors that could cause premature failures.


As for the stock piston goes, I think the success you are seeing might be because of the extra things you do and the care you take when the motor goes back together.

I just got done rebuilding a '16 Axys with less than 600 miles. Loss and faded RPM's. Installed Fix Kit and RPM are right back to 8,500. Rings were wasted and pistons had 0.014" and 0.015" clearance.

I have another one to do that is fouling plugs like crazy. 500 miles. Everything's been done to it outside going in. Carl's has told him it's time to go into the motor.

diamonddave said:

Hi Dan,


Thanks for the post. It's great to have you on here. And thank you for the order a couple weeks ago. Jon spelled my last name wrong LOL.

I only have experience with one aftermarket piston for the 800 CFI and that would be the one that comes in the MTNTK Fix Kit which is the taller Weisco piston and uses the cylinder shim.

I'm curious if any of the findings you are seeing are with this particular piston OR are with the direct copy of the stock piston?

The reason I ask is because I have installed approximately 35 of these kits with zero comebacks, 4 corner seizes, issue's, runnability issues, etc. since they came out in 2010ish. Some of them have been installed (with my perfection attention to detail) with your gusseted cylinders, other's just R&R'd, and some with brand new mono's, even with the 08-09 thin cylinders. I could not work on these my way paid by flat rate time.

In fact, I like this kit so much I was telling Justin I was going to ask you to build me a Longrod and shim that will allow me to run the MTNTK Fix Kit this summer.

As for your results, I completely understand your sample size and mine are different and could be explain some of the reason why we are seeing different results (if we're comparing results from the same piston). I also have to question the ability of some of the installer's, condition of the rest of the motor, not having the right tools, drinking alcohol during assy. and a multitude of other factors that could cause premature failures.


As for the stock piston goes, I think the success you are seeing might be because of the extra things you do and the care you take when the motor goes back together.

I just got done rebuilding a '16 Axys with less than 600 miles. Loss and faded RPM's. Installed Fix Kit and RPM are right back to 8,500. Rings were wasted and pistons had 0.014" and 0.015" clearance.

I have another one to do that is fouling plugs like crazy. 500 miles. Everything's been done to it outside going in. Carl's has told him it's time to go into the motor.

Click to expand...

Hello Matty, sparky, & Dave. And great to see you guys and thank you for everything you guys do.

Dave, just to clear the air I have never installed a Mtn Tk kit. if clearance correctly with good sled owner prep you have proved with your tactics they work with what you do ( thumbs up )

Lots of options out there, and it is important the consumer gets a product he as some understanding of and it it really works good for an extended period of time.

I have found over time with motor & cylinder sales numbers past what i ever dreamed possible and motors all over the world i can't tip toe around with extensive break in procedures and warm up tactics.... ( some sold to - 2,3, even 4 different owners....) I have to accept that some motors are going to treated like he!l and put into deep snow with zero break in time and held WOT the first time its rode.

OEM are the only Pistons i personally have the stomach for in the 3 year Motor.

I would actually like to set a Long Rod up with a MTN Tk kit with some reasonable clearance to see myself a truely long 3 year test.

1000 to 1500 mountain miles per season.

Not a Midwestern type test.... average 1 to 2 trips per year, that is not a test to my shop.

Dan

Dan,
Great information! Although I haven't used your services yet I know I will one day. I do not not know how old you are and I only ask two things of you, please don't ever die and if you decide to retire, please pass your knowledge along to a relative or someone else to keep your legacy going.

Drewd said:

Dan,
Great information! Although I haven't used your services yet I know I will one day. I do not not know how old you are and I only ask two things of you, please don't ever die and if you decide to retire, please pass your knowledge along to a relative or someone else to keep your legacy going.

Click to expand...

HAHAHAHA !! LOL !! humble

Well thanks for the wish for eternal life !

That's about the biggest over praise ever given !

54 years old and barely made it out of high school, low on IQ just got some time in service and Been around the block on this motor. Since 2009 In the area of 450 Long Rod 800 motors & well over 350 short rod motors on the snow and Fair amount of top-end kits.

Recalled close to 200 motors in 2014 thru Oct 2015 for a defective Rod bearing & cylinder finish. You are sure to learn a lot thru a war like that.

I have made some poor honing desisions on this motor in pass years.

No motor has caused more confusion then the Polaris 800 small block

Dan

Good to see you here, Dan. This is Dusty from Owatonna that brought you the messed up primary this fall. Appreciate the insight on the polaris 800, considering options on my 14 pro engine before my big BC trip in February.

So i have an 11 assualt rmk. What would be the difference between the OEM pistons for that motor and the axys pistons? I just lost a top end with aftermarket pistons and I am considering axys pistons

Besides the skill and experience, it takes a lot of balls to "personally" warranty any motor for 3yrs in this sport.

Good on you Dan.

geo said:

Besides the skill and experience, it takes a lot of balls to "personally" warranty any motor for 3yrs in this sport.

Click to expand...

You just said a mouthful !

Whats really great about the 3 year warranty is the fact that it taught Indy Specialty at a staggering rate how to get pistons to last...

not to very long ago that 3 year warranty damn near broke the bank reserves at Indy Specialty.

I also learned, that if you take care of your customers it comes back you at a level one almost cannot believe is possible.

Besides there is plenty of work out there without throwing bullchit curve balls to sell parts that were not needed.... ( Indy Specialty sells Labor ) I hate selling parts unless I made them from a Billet chunk of metal.

Hi Dusty, i remember you ! call the shop if you need help.

* ( Mtnsledder94 ) * - the difference between Axys & the part number you would get if you ordered 2011 800 OEM is basically..... ** grooves ** $45 dollars more grooves that seem to do nothing.

Polaris has been messing around with the rear cyl transfer port width since 2011 and newer..... so intern they have different part number OEM piston over the year mainly the difference has been ring locator location.

And the wide rear transfer port does nothing for high elevation motors except make them less responsive & more undependable. ( Since 2017 most 2011 cylinders that leave Indy Specialty come with a slightly narrower rear transfer port for better low end punch & lower ring life. ) ** Widens the bridge between the rear center & 2 back transfer ports where the ring locators travel up & down **

Indy Specialty most often uses the Non-grooved Polaris pistons in all the 800 motors.

$260 dollars verses $215.00

Dan

Thanks Dan

I have a 2014 motor with over 3000 miles and was thinking about changing pistons, but based on what you recommend I'm not going to touch it, as it still runs as good now as when it was new.