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What Makes the 800 down on Power? (lots of 2 stroke info)

m1kflyingtiger

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Jan 28, 2010
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Soldotna, AK
I'm not familiar with the internals of the cfi 700, but was it essentially the same motor with thicker cylanders? Resulting in a much more reliable power plant?
 
R
Sep 8, 2013
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Interior Alaska
Im wondering...wouldnt putting the coolant inlet closer to the exhaust side tame the cylinder heat on the exhuast side...or else 2 cooling inlets for each cylinder both closer to the exhaust, and as stated a combustion chamber on the intake side?
 
R
Sep 8, 2013
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Interior Alaska
Without getting into all the discussion here...

The OEM pistons do NOT have excessive clearance..they come in between .005" and .006" clearance . So, Polaris does not send these engines out with a loose piston..

As for the cylinder distorting... That is another subject,, we do not see them distort.. but it is a poor design. but the cylinder is staying round above the exhaust port..

Well...ive heard for most of the 08 10 cfis had .008 clearance stock...

Not sure if its true or not but ok...its going to take alot to convince me considering you claim 150 hp stock out of a poo 800
 
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RKT

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Jul 19, 2001
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Preston, Idaho
www.2strokeheads.com
Well...ive heard for most of the 08 10 cfis had .008 clearance stock...

Not sure if its true or not but ok...its going to take alot to convince me considering you claim 150 hp stock out of a poo 800

Well, I am not trying to convince you of any stock HP figures.. But that data is there from several different dyno facilities to show the 150HP

As for the .008" clearance?? I thought you said that you have never seen inside of the engine?? So, how can you dispute the clearances..

The stock bore is 3.3465" so measure or just read from the top of the OEM piston and do the math.. you will find the clearances to be .005"-.006" .. now after 200 miles (orless) you can easily have .008" (this is the piston problem that doe snot exist:face-icon-small-con) but NEW, they are in a good spec.. they just do not stay there very long..
 
R
Sep 8, 2013
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Interior Alaska
Well, I am not trying to convince you of any stock HP figures.. But that data is there from several different dyno facilities to show the 150HP

As for the .008" clearance?? I thought you said that you have never seen inside of the engine?? So, how can you dispute the clearances..

The stock bore is 3.3465" so measure or just read from the top of the OEM piston and do the math.. you will find the clearances to be .005"-.006" .. now after 200 miles (orless) you can easily have .008" (this is the piston problem that doe snot exist:face-icon-small-con) but NEW, they are in a good spec.. they just do not stay there very long..


For all i know...aaen is the only dyno sheet that says the stock pro is 155 hp...and if you ever read aaens books you would soon realize why aaen isnt a good place to count on

Bikeman, and cpi both show the dyno sheet...mid 140s are the numbers

If you truely think the pro is 150 hp stock that says alot...
 
R

RKT

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Jul 19, 2001
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For all i know...aaen is the only dyno sheet that says the stock pro is 155 hp...and if you ever read aaens books you would soon realize why aaen isnt a good place to count on

Bikeman, and cpi both show the dyno sheet...mid 140s are the numbers

If you truely think the pro is 150 hp stock that says alot...

I guess it really does not matter what the stock HP really is.. but there are more dyno facilities that CPI , AAEN, or Bikeman...
The Bikeman dyno is with an engine that has 1800 miles on it.. so, YES, the HP drops due to the piston being worn.. but NEW... 150.. Ask them...

Anyway.. not here to argue with ya..

You are asking for information on clearances and what not.. I am simply supplying you with some info and you choose to discard it???

If you already have tha answers, then why are you asking?

So, what do the stock OEM pistons measure??
 
R
Sep 8, 2013
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Interior Alaska
I guess it really does not matter what the stock HP really is.. but there are more dyno facilities that CPI , AAEN, or Bikeman...
The Bikeman dyno is with an engine that has 1800 miles on it.. so, YES, the HP drops due to the piston being worn.. but NEW... 150.. Ask them...

Anyway.. not here to argue with ya..

You are asking for information on clearances and what not.. I am simply supplying you with some info and you choose to discard it???

If you already have tha answers, then why are you asking?

So, what do the stock OEM pistons measure??

Its not the horsepower that is what matter its more of that you would try to lie to your customers and pushing numbers further than they actually are...im not sure about any of the other guys here but this makes it hard for me to believe anything from you...it is very probable that bikeman turned up their oil pump considering they have a tutorial about it...and 1800 isnt much, as stated above more oil usually means better power...im just wondering...where are you getting your dyno numbers from?
 
R

RKT

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Jul 19, 2001
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Preston, Idaho
www.2strokeheads.com
Its not the horsepower that is what matter its more of that you would try to lie to your customers and pushing numbers further than they actually are...im not sure about any of the other guys here but this makes it hard for me to believe anything from you...it is very probable that bikeman turned up their oil pump considering they have a tutorial about it...and 1800 isnt much, as stated above more oil usually means better power...im just wondering...where are you getting your dyno numbers from?


Well.. not seeing where anybody is lying about anything... Where am I pushing the 150 stock HP?? But if you see that then???

As for believing you.. Let's see.. new member on here with a sudden interest in a very controversal engine:face-icon-small-coo.. So what is your name??
You have a bunch of "book theory" going on but claim to have never seen this engine??:face-icon-small-con

You come out on the attack calling people liars when you have NO data to show otherwise??

Combustion chamber on the intake side?? Aah.. loop scavenged engine.. Check your 2 stroke books you are referencing again .. we are not talking a cross scavenged engine....

Again.. I ask you.. What is your name?? History with 2 strokes?
Also: What is the stock OEM Polaris piston dimension?

Simple questions.... look forward to the answers..

Also, there is no offset with the 2013 cylinder or crank.. zero offset with respect to centerline....
 
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V

Vfrtrader

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Aug 25, 2009
258
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Cache Valley, UT
So, Kelsey, you are saying that a new motor is fine but after several 100 miles the piston will rock and slap around causing the piston to were down as Joey but Bikeman said? How does your kit over come this problem?
 
V

Vi-PEC Powersports

Well-known member
Aug 17, 2011
711
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CANADA
I guess it really does not matter what the stock HP really is.. but there are more dyno facilities that CPI , AAEN, or Bikeman...
The Bikeman dyno is with an engine that has 1800 miles on it.. so, YES, the HP drops due to the piston being worn.. but NEW... 150.. Ask them.
With an intake air temp of 20 celsius, none of the 11-12-13 poo made more than 129-130 crank Hp where the Cat with the same intake temp made 147-148 HP...run after run after run and on new sleds(eddie current engine dyno) , all those measurements taken along hundreds of testing hours developing our ECUs.
One simple reason why Cat makes around 18 more hp is compression ratio: Cat is 13.5:1 and Polaris is 12.0:1.......there is not one simple answer to the HP difference but certainly the compression ratio is the major player here.



vi-pec powersports
 
R
Sep 8, 2013
232
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Interior Alaska
Well.. not seeing where anybody is lying about anything... Where am I pushing the 150 stock HP?? But if you see that then???

As for believing you.. Let's see.. new member on here with a sudden interest in a very controversal engine:face-icon-small-coo.. So what is your name??
You have a bunch of "book theory" going on but claim to have never seen this engine??:face-icon-small-con

You come out on the attack calling people liars when you have NO data to show otherwise??

Combustion chamber on the intake side?? Aah.. loop scavenged engine.. Check your 2 stroke books you are referencing again .. we are not talking a cross scavenged engine....

Again.. I ask you.. What is your name?? History with 2 strokes?
Also: What is the stock OEM Polaris piston dimension?

Simple questions.... look forward to the answers..

Also, there is no offset with the 2013 cylinder or crank.. zero offset with respect to centerline....



Well...it really says alot that you dont know where you said polaris 800 was 150 hp stock...why dont you look at your website...i was interested in buying some of your stuff...until i realized you show no dyno charts or even hp numbers with yout polaris big bore kit...only said it is cheap...which indeed it seems

Since your website is made for 2 stroke heads...you should know an offset combustion chamber to the intake side evens out the heat inside the cylinder and the intake charge is cooler because its away from the exhaust side

Now where did i say i havnt seen this engine? I said i didnt really look and measure specs of this motor before

Now are you looking for piston dimensions or clearence between the cylinder wall? These are different things here...
 
R
Sep 8, 2013
232
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Interior Alaska
With an intake air temp of 20 celsius, none of the 11-12-13 poo made more than 129-130 crank Hp where the Cat with the same intake temp made 147-148 HP...run after run after run and on new sleds(eddie current engine dyno) , all those measurements taken along hundreds of testing hours developing our ECUs.
One simple reason why Cat makes around 18 more hp is compression ratio: Cat is 13.5:1 and Polaris is 12.0:1.......there is not one simple answer to the HP difference but certainly the compression ratio is the major player here.



vi-pec powersports

If this is true rktek says the 800 cat is almost 170 hp...lol
 

mtncat1

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Oct 19, 2008
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south jordan ut.
I will add one more little tidbit that will really get the engine guys going...there is nothing that wrong with a stock Polaris pison..Yep that's right, they are quite fine for a stock piston..the cylinder is the problem...(anyone wonder why Carl's uses their own cylinders for their bigbore? ) the stock cylinder just doesn't have enough meat to hold a round symmetrical bore when run hard. Why you ask? well if you set a Polaris cylinder next to a cat first thing you will notice is the casting is just lighter, not as much material, not as big of water passages(holds less coolant) and most important, a deep exhaust port/powervalve passage which allows a lot of exhaust heat to be retained in that side of the casting, and when combined with less casting thickness causes the cylinder to distort out of round more especially above the exhaust port. that's why everyone want to sell you pistons for your motor..they are trying to do a better job controlling the piston expansion/contraction so they can tighten bore clearences and make it live when in reality what would fix it is a better/stiffer cylinder with better cooling around the exhaust port..(hint, go look at Polaris ultra cylinders..first year vrs last year..quite obvious)
I don't know about the thickness issue on the stock cylinders, but here is a picture comparing a 910 cylinder to stock, 910 looks pretty thin to me

big bore1.JPG
 
R
Sep 8, 2013
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Interior Alaska
I don't know about the thickness issue on the stock cylinders, but here is a picture comparing a 910 cylinder to stock, 910 looks pretty thin to me

bikeman also bores out cylinders to 860...it the cylinder theory is true those would go down like crazy,im not sure how much metal you can add to reinforce the intake side before the cylinder wont fit to the case but that looks fine to me...i would say my polaris 700 cylinders are about the squirt width on the intake side...but mine doesnt have the skirt chunked out for more flow to the boost port like those ones do aswell
 
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JMCX

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Nov 26, 2007
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Alberta
I think after warrantying a bazillion engines in the Dragons Polaris brass said 'enough of this' and they detuned it.

It's not just compression. The PAR 13.6 head doesn't add anything on the top. I have one.

Somehow, with less power and apparently being the heaviest once it rolls across a snowflake, my Pro works damn good.
 
R
Sep 8, 2013
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28
Interior Alaska
the point of this thread is to find out where polaris detuned the motor in which area...did they put a too agressive exhaust valve on it? or is the pipe the place they decided to go when taking power away? lower compression could be part of the cause...but a 13.something:1 head from bikeman adds 6 hp...at most...and thats for only 2 thousand feet and above on pump premium...does anyone here know where the fuel injectors are placed, and where they are pointed?
 

mtncat1

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south jordan ut.
I think the pro 800 needs more aggressive porting and a better piston and head design. but I don't have to worry about passing an I/m test:face-icon-small-hap
 
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