FYI..NEW Product Announcement. Polaris 800 Direct Replacement Pistons

[Pro-8250]

THANKS EVERYONE!

There are a lot of smart people here, and I am going off the subject a little but I have to ask. I have 2-2011 Pro's and I have thought about going with RKT's upgrade, or upgrading to 2-2013's. Is the motor on the 2013 exactly the same as the 2011? If it is the same, I just maybe better off keeping mine and upgrading with RKT. I didn't want to start a new thread as RKT mentioned. There's just too many experts chimed in here and I could use some direct advise. No I am not being a smart a$$, you guys are way over my head.
I guess for me it boils down to, will the 2013 have the exact same issues as some have had with the 2011's?
My 2011 155" 1880 miles. One bad exhaust temp sensor.
My 2011 163" 883 miles. No issues. (Except for that stupid rock!)
Thanks!

 

[Jimb]

There are a lot of smart people here, and I am going off the subject a little but I have to ask. I have 2-2011 Pro's and I have thought about going with RKT's upgrade, or upgrading to 2-2013's. Is the motor on the 2013 exactly the same as the 2011? If it is the same, I just maybe better off keeping mine and upgrading with RKT. I didn't want to start a new thread as RKT mentioned. There's just too many experts chimed in here and I could use some direct advise. No I am not being a smart a$$, you guys are way over my head.
I guess for me it boils down to, will the 2013 have the exact same issues as some have had with the 2011's?
My 2011 155" 1880 miles. One bad exhaust temp sensor.
My 2011 163" 883 miles. No issues. (Except for that stupid rock!)
Thanks!

Good question I've been debating the same thought. Anyone know?

 

[Rally2]

Yes I will answer, I will do the cylinder work to anyones cylinder to run anyones piston I do not care what piston you run as long as I do not have to warranty it.

Broken sleeves do not matter and I do not need the busted piece.

I just need finish bore size, And the Finsihed Price is $795.00 ready to install. Pistons Not included. No warranty.

If I supply the Pistons its $995.00 complete with a matched set of Piston & Top-end Gasket set.

Dan

Hi Dan, to clarify if you do the cylinder mod with your pistons for $995 is warranty offered?

 

[gman086]

There are a lot of smart people here, and I am going off the subject a little but I have to ask. I have 2-2011 Pro's and I have thought about going with RKT's upgrade, or upgrading to 2-2013's. Is the motor on the 2013 exactly the same as the 2011? If it is the same, I just maybe better off keeping mine and upgrading with RKT. I didn't want to start a new thread as RKT mentioned. There's just too many experts chimed in here and I could use some direct advise. No I am not being a smart a$$, you guys are way over my head.
I guess for me it boils down to, will the 2013 have the exact same issues as some have had with the 2011's?
My 2011 155" 1880 miles. One bad exhaust temp sensor.
My 2011 163" 883 miles. No issues. (Except for that stupid rock!)
Thanks!

I was informed today, by an industry insider I can trust, that the 2013 Pros definitely have new cylinders machined with thicker/stronger skirts and they've addressed the piston issue too. They know about the problem!

Have FUN!

G MAN

PS - I'm thinking Dan's cylinders with Kelsey's big bore for me... now excuse me while I find a bank to rob!

 

[indydan]

Hi Dan, to clarify if you do the cylinder mod with your pistons for $995 is warranty offered?

Yes if you get the package from me it has a 3 year warranty.

If you want the cylinder work only from me and you want to run Kelsey's Pistons I will still warranty the cylinder work.

If you want Kelsey's Big Bore I will still do the cylinder work but Big Bore motors are never warranty in my book.

If you want the cylinder work done with any of Kelsey's kits then the billing will go thru Kelsey's shop and he will handle the billing.



Dan

 

[Rally2]

For general info see attached pics of a cylinder from a 2009 Cat M8

 

[Angermangement890]

^^^^^^^^^^^^^^^^^^^^^^^
Good info/pics

For fun today I measured a whole bunch of cylinders for comparison purposes.


09 M8
85mm bore
70mm stroke
Rod Length130mm rod
Rod ratio 1.85
8.7mm/0.3427" on the intake side of the skirt
8.4mm/.331 on the exhaust side of the skirt

09 Ski-Doo 800R
82mm bore
75.7mm stroke
Rod length 132mm
Rod Ratio 1.74
5.25mm/0.207" on the intake side of the skirt
5.0mm/0.197" on the exhaust side of the skirt

09 Polaris 800
85mm bore
70mm stroke
132mm rod length
1.88 Rod ratio
5.55mm/0.218" on the intake side of the skirt
5.0mm/0.197" on the exhaust side of the skirt

09 Polaris 600 R
73.8mm bore
70mm stroke
132mm rod length
1.88 Rod Ratio
8.7mm/0.343" on the intake side of the skirt
9.0mm/0.354" on the exhaust side of the skirt
Piston Weight: 385.8g
Including: wristpin, circlips, rings
Piston Make: Wiseco

09 Polaris 700
81mm bore
68mm stroke
128mm rod length
1.88 Rod Ratio
5.5mm/0.217" on the intake side of the skirt
5.4mm/0.213" on the exhaust side of the skirt
Piston Weight: 498g
Including: wristpin, rings, circlips (in plastic)
Piston Make: SPI

09 Polaris 600 (4 injector)
77.25mm Bore
64mm Stroke
128mm Rod length
2.0 Rod Ratio
6.48mm/0.255" on the intake side of the skirt
6.35mm/0.250" on the exhaust side of the skirt
Piston Weight: 444g
Including: Wristpin, circlips and rings (In plastic)
Piston Make: OEM Polaris

09 Polaris 660 (4 injector)
81mm Bore
64mm Stroke
128mm Rod Length
2.0 Rod Ratio
4.6mm/0.181" on the intake side of the skirt
4.5mm/0.177" on the exhaust side of the skirt
Piston Weight: 498g
including: wristpin rings, circlips (in plastic)
Piston Make: SPI

05 Polaris 797 Race engine
85mm bore
70mm stroke
128mm rod
1.83 Rod Ratio
4.5mm/0.177" on the intake side of the skirt
4.5mm/0.177" on the exhaust side of the skirt
Piston Weight: 470.3g measured
Including: Wristpin, rings, circlips
Piston Make: Wiseco

05 Polaris 797 Race engine LR combo
85mm bore
70mm stroke
136mm Rod length
1.94 Rod Ratio
4.5mm/0.177" on the intake side of the skirt
4.5mm/0.177" on the exhaust side of the skirt
Piston Weight: 470.3g measured
Including: Wristpin, rings, circlips
Piston Make: Wiseco

Wristpin weights:
Polaris 600: 94.4g
Wiseco CW20: 60g
SPI 700 CFI: 87.7g

Edited:
4-26-12, to include piston weights, more to come
5-01-12, to include ski-doo and Artic Cat Rod lengths/ratios

All dimensions were taken at the same time, conversion for millimeters to inches was .0394" = 1 millimeter. As soon as my calibration weight gets here for my 600g scale, I will be posting the piston weights for the above engines weighed with wristpin, circlips and rings installed.

If anyone has the actual rod lenghts for the items in bold, please post them.

I find it interesting that Ski-doo runs about the same skirt thickness as the Polaris, but uses a piston that is 3mm smaller in dia. Another interesting point to me is that the 800 Arctic Cat has a cylinder skirt that is 37% thicker than the polaris 800. I also find it weird that the 600R and CFI have the thickest cylinder skirts of any of the Polaris engines. And the 600 CFI has the best rod ratio of all the Polaris engines.

 

[indydan]

^^^^^^^^^^^^^^^^^^^^^^^
Good info/pics

For fun today I measured a whole bunch of cylinders for comparison purposes.



I find it interesting that Ski-doo runs about the same skirt thickness as the Polaris, but uses a piston that is 3mm smaller in dia. Another interesting point to me is that the 800 Arctic Cat has a cylinder skirt that is 37% thicker than the polaris 800. I also find it weird that the 600R and CFI have the thickest cylinder skirts of any of the Polaris engines. And the 600 CFI has the best rod ratio of all the Polaris engines.

Yep, Notice the 700 @ 81mm bore 1.88 rod ratio and no piston problems.

Then Polaris went to 85mm bore and the 1.88 did not work out so well.

With my long rod motor 1.94 any piston will work and last along time.

Dan

 

[gman086]

Yep, Notice the 700 @ 81mm bore 1.88 rod ratio and no piston problems.

Then Polaris went to 85mm bore and the 1.88 did not work out so well.

With my long rod motor 1.94 any piston will work and last along time.

Dan

Dan,

What does that do to the stroke? I kind of like the short stroke on the Polaris 800 as that adds a lot of low end snap/pull. Also the Doo 800R seems to get away with the thinner skirts because of the longer stroke? My 800R definitely doesn't have the low end snap that my 800 CFI2 has (but has better top end).

Thanks,

G

 

[beamslayer]

I was asked a question on the drop in kits from a friend of mine today that I guess I never thought of ( do we need to check bore size before ordering pistons or there is not enough cylinder wear or out of round to worry about ?
What type of hone would you prefer we use to deglaze cylinders?

 

[RKT]

I was asked a question on the drop in kits from a friend of mine today that I guess I never thought of ( do we need to check bore size before ordering pistons or there is not enough cylinder wear or out of round to worry about ?
What type of hone would you prefer we use to deglaze cylinders?

The bore size should not change..meaning.. the NikaSil does not wear.. So unless you have had a Nikasil replate, the bore willbe correct

To deglaze, I use a dingle-berry hone (180 Grit) but there are several other methods that work as well

 

[Rally2]

Dan,

What does that do to the stroke?


G

The longer rods won't change the stroke but the different geometry will reduce side loading on the piston/cylinder skirt. Piston dwell and velocity numbers are also affected but going from 1.88 -> 1.94 you likely won't notice any change in engine performance. As I understand it anyways..

 

[jeepin270]

Is there piston options if someone wanted to go with a boreable sleeve?

 

[RKT]

Is there piston options if someone wanted to go with a boreable sleeve?

With proper notice, I can get any size piston you wish..

 

[jeepin270]

Is there a reason why people don't get rid of the nik'ed cylinders ? I think it would be a lot cheaper and faster to have a cylinder bored out.

 

[indydan]

Dan,

What does that do to the stroke? I kind of like the short stroke on the Polaris 800 as that adds a lot of low end snap/pull. Also the Doo 800R seems to get away with the thinner skirts because of the longer stroke? My 800R definitely doesn't have the low end snap that my 800 CFI2 has (but has better top end).

Thanks,

G

Yes as Rally2 said the stroke doesn't change its the angle of attack on the rod that gets better. You example about short stroke compared to the Ski Doo is an incorrect comparison. There are other reason the Polaris feels better to you then the 800R but that is a completely different subject in a way.

As far as steel sleeves go its not a very good trade off for plating.

And as far as cylinder condition & size goes it should be measured and checked by a experienced shop.

If its not perfect it must be diamond honed with a hone above and behond what the basic consumer or dealer ship has. Plated cylinders can be honed effectively with a hand drill & the cylinder clamper to the side of a parts washer.............Nor can you do it effectly on on a sunnen pin hone where you hold the cylinder with your hands.

Arctic Cat use to have in their shop manual to ding-ball hone cylinders before replacment of the rings they have since learnd it doesn't work very good. Honing is the last step left to get the motor in position for its best performance by getting the cylinder surface correct for ring surface cutting. If the surface is to smooth the rings never cut it, if te cylinder is to aggressive the rings get over cut and the ring end-gap gets way to wide.

Dan

 

[Norway]

As far as steel sleeves go its not a very good trade off for plating.

Dan

How would you summarize the difference for these engines? Since both cylinder distortion and piston to cylinder clearance seems to be a problem, wont steel sleeves be a give and take scenario?

 

[indydan]

How would you summarize the difference for these engines? Since both cylinder distortion and piston to cylinder clearance seems to be a problem, wont steel sleeves be a give and take scenario?

Hi Rune, I hope all is well and good with you.

Quote " Give and take " Yes thats what it would be - The sleeve will add strength, But you give up quick heat transfer, expansion speed, and steel does not wear as good as plating.

Dan