Just a little FYI on the Polaris CFI Engine and surrounding rumors

[RK Tek]

What about this question? don't think its a good one?

What is the question?? Do you mean do I want to argue with this guy because he does not believe me???

It has already been mentioned that there is no Offset crank.. This has been proven many times and VERIFIED by Polaris themselves...

You have one guy trying to convince everybody that the crank is offset, the rod ratio is lacking, and that the bores are not round--> just to try and sell you some parts.

You would think that will all the "mis-information" that surrounds this power-plant, one would like some hard data??

ALL this data I have given you guys is verified and proven.. But I have stated that it is my opinion, backed by real hard data. It is just information..

If you guys do not choose to believe it, than that is your choice and I respect that 100%..

I am just trying to help you out with providing REAL information ... what you do with the information is entirely up to you..

 

[lilduke]

What is the question?? Do you mean do I want to argue with this guy because he does not believe me???

It has already been mentioned that there is no Offset crank.. This has been proven many times and VERIFIED by Polaris themselves...

You have one guy trying to convince everybody that the crank is offset, the rod ratio is lacking, and that the bores are not round--> just to try and sell you some parts.

ALL this data I have given you guys is verified and proven.. But I have stated that it is my opinion, backed by real hard data. It is just information..

If you guys do not choose to believe it, than that is your choice and I respect that 100%..

I am just trying to help you out with providing REAL information ... what you do with the information is entirely up to you..

I respect your info and Im sure everyone really appreciates it. So thank you. How ever I feel this (If there is no offset in the '13 engines then why are the '13 case halves described in the parts manual as "offset" and not interchangeable with previous engines? ) is a relevant question. I've never even seen a 2013 Polaris parts manual so this guy could be full of chit for all I know. So does the parts manual describe it as offset, yes or no? And are the 2012 and 2013 cases interchangeable or not? and if not whats the difference? Thanks

 

[RK Tek]

I respect your info and Im sure everyone really appreciates it. So thank you. How ever I feel this (If there is no offset in the '13 engines then why are the '13 case halves described in the parts manual as "offset" and not interchangeable with previous engines? ) is a relevant question. I've never even seen a 2013 Polaris parts manual so this guy could be full of chit for all I know. So does the parts manual describe it as offset, yes or no? And are the 2012 and 2013 cases interchangeable or not? and if not whats the difference? Thanks

Why Polaris choose any name for any thing is not known.. what IS known is that the crank is on center... The crank nor the cylinder is OFFSET!

The 2013 crank will bolt into ANY of the CFI engines from 2008-2013. Bolts right in and functions perfectly..

The 2013 cylinder will NOT bolt onto a 2011 or 2012 upper case half.. BECAUSE IT IS THICKER!! So, the upper case half will not allow for this thicker skirt (the thicker skirt will not pass thru the case .) Make sense??

So, very easy to fix.. you can bolt on a 2013 upper half to the 2011 or a 2012 OR you can simply machine the upper case half from ANY CFI engine (2008-2012) to allow for this thicker skirt.We have done these and they work fine..

OR in direct answer to your question.. YES, the 2013 cases are interchangable..you just have to match the correct year cylinder to the correct year upper case half.

Hope this helps

 

[lilduke]

Why Polaris choose any name for any thing is not known.. what IS known is that the crank is on center...

The 2013 crank will bolt into ANY of the CFI engines from 2008-2013. Bolts right in and functions perfectly..

The 2013 cylinder will NOT bolt onto a 2011 or 2012 upper case half.. BECAUSE IT IS THICKER!! So, the upper case half will not allow for this thicker skirt (the thicker skirt will not pass thru the case .) Make sense??

So, very easy to fix.. you can bolt on a 2013 upper half to the 2011 or a 2012 OR you can simply machine the upper case half from ANY CFI engine (2008-2012) to allow for this thicker skirt.We have done these and they work fine..

OR in direct answer to your question.. YES, the 2013 cases are interchangable..you just have to match the correct year cylinder to the correct year upper case half.

Hope this helps

So the answer is YES the 2013 parts manual describes it as offset then? ok thanks for the info

 

[RK Tek]

So the answer is YES the 2013 parts manual describes it as offset then? ok thanks for the info

Honestly, I do not know what Polaris calls it.. I have never looked it up..

Again,, all I know is what the reality is..

 

[lilduke]

Honestly, I do not know what Polaris calls it.. I have never looked it up..

Again,, all I know is what the reality is..

OK thanks.

 

[Rhodesie]

on the e-fish on the extranet the case halves are not noted as offset. the monoblock is noted as offset but not the cases. both the mape & fuji crankshaft part#'s are still both available. when they deplete the mape stock then than number with more than likely sub to the Fuji number.

 

[MarkCos]

So RK
All sounds good , how do I know if I am just
putting a new piston in a worn out cylinder ?
could it not just crap out as fast as just leaving in the stock piston ?
due toto lose or improper fit
would it not be better to put a new head on with the new pistons ?

 

[MarkCos]

Sorry new cylinder I men't
not head

 

[rmscustom]

Kelsey, I will be measuring my cylinders today and stock pistons with 1350 miles on... What should the cylinders measure?

 

[LennyR]

Kelsey I have one of your heads and a helix for a tied clutch with your recommended springs, which you sold me , i assume after rigorous testing. If you pay for the shippingbi'll sell the whole package back to you for 25 per cent of what I paid you, you can resell em and make margin again, great deal for ya.
Oh, and they were only used a couple trips.
PS, maybe don't suggest the new buyer to call me for a reference, may not work out.

 

[RK Tek]

So RK
All sounds good , how do I know if I am just
putting a new piston in a worn out cylinder ?
could it not just crap out as fast as just leaving in the stock piston ?
due toto lose or improper fit
would it not be better to put a new head on with the new pistons ?

NikaSil plating is near diamond hardness.. that is why it is used.. because it wears so well..

You are rubbing a smooth ductile steel (light steel) ring against a plating that is MUCH harder.. Can the plating wear? Yes, but it is like rubbing wood on a rock.. the wood (rings) wear much faster than the rock (plating) so, it is always wise to check the bore size should be 3.3465" +- .0005" but the chances that it is worn are low.. But always check..

To be 100% accurate.. your rings nor pistons never actually make direct contact with the cylinder wall (unless you are seizing the engine) these always ride on a thin oil barrier.. so another reason why the plating remains on size.

 

[rmscustom]

So here's what I found.
Top of both cylinders parallel and perpendicular to the crank were 3.3465"

pto side bottom of cylinder perpendicular to crank 3.3468"
pto side bottom of cylinder parallel to crank 3.3471"

mag side bottom of cylinder perpendicular to crank 3.3468"
mag side bottom of cylinder parallel to crank 3.3474"

both pistons below the ring groove perpendicular to the pin 3.333"
both pistons bottom of skirts perpendicular to the pin 3.339"

Kelsey,
Whats your thoughts on my cylinders?
I'm assuming with the large cylinder to piston clearance topped with my rings flaking my power loss is no longer a mystery.

 

[RK Tek]

So here's what I found.
Top of both cylinders parallel and perpendicular to the crank were 3.3465"

pto side bottom of cylinder perpendicular to crank 3.3468"
pto side bottom of cylinder parallel to crank 3.3471"

mag side bottom of cylinder perpendicular to crank 3.3468"
mag side bottom of cylinder parallel to crank 3.3474"

both pistons below the ring groove perpendicular to the pin 3.333"
both pistons bottom of skirts perpendicular to the pin 3.339"

Kelsey,
Whats your thoughts on my cylinders?
I'm assuming with the large cylinder to piston clearance topped with my rings flaking my power loss is no longer a mystery.

You have about .008" clearance.. Actually,this is better than most with that many miles.. (do you ride flats or mountains?) most see upwards of .009"

Your cylinders seem to be in spec..(big shocker they are not .002"-003" out like the rumor states)

You should measure the cylinders above the exhaust port.. this is where it counts in terms of sizing.. Please measure there and see what numbers you come up with..

Edit: Didn't see that you did that.. AND they are right on the money!! Shocker!!

But, yes, flaked rings will rob power like crazy.. the piston clearance is out of spec as well... So, a deglaze and some new pistons and you should get your performance back.

 

[rmscustom]

Mostly mountain miles. Only used legend oil turned up to about 35 to 1 if that makes a difference. Any concern with the bottom of the cylinders being that far out of round?

 

[RK Tek]

Legend is the best out there and yes, that and the high ratio would be a reason why yours are not as worn as others.. NICE!
As far as the bottoms... they are not part of any power making process..AT ALL.. and you are still within specs.. The loose piston thrusting against the unsupported lower cylinder skirt can "flare" it some.. But you are still in spec

Do me a favor and measure about 1.5 to 2" up from the skirt bottom and see what you get for dimension

 

[rmscustom]

I had my bro in law measure them for me at his hydraulic cylinder shop so I'd have to re measure another time, we weren't measuring at the very bottom of the skirt though... Just so we're on the same page, the wider measurement in the bottom of the cylinders was parallel to the crank and not perpendicular to it so the flaring of the skirts would have no effect there... Or am I missing something?

edit, I just seen your edit on measuring above the exhaust port. Please still comment on the bottom being out of round.

 

[dirtbiker77]

Thanks Kelsey for all the info. Think this is actually one of the most useful post for the poo's in a long time. I plan on ordering a kit but was wondering if your head is the stock compression? I could have missed it somewhere but I ask anyways. If its stock compression then are your pistons good for the extra compression and or even boost?

 

[RK Tek]

Thanks Kelsey for all the info. Think this is actually one of the most useful post for the poo's in a long time. I plan on ordering a kit but was wondering if your head is the stock compression? I could have missed it somewhere but I ask anyways. If its stock compression then are your pistons good for the extra compression and or even boost?

My pleassure to help.. It is just that there is so much BS that surrounds this enigne.. I felt it would be good to try and get the real facts out there vs. the "fake" facts.

As for my heads and pistons.. We have ALL compression ratio heads, we make them all custom to order.. and YES the piston are in MANY boosted sleds.. they hold up great and are truly the best piston you can get for this engine.. NOTE: These pistons are specifically design to NOT have to be treated any different than stock.. It is all in the design....

 

[RK Tek]

As far as the bottoms... they are not part of any power making process..AT ALL.. and you are still within specs.. The loose piston thrusting against the unsupported lower cylinder skirt can "flare" it some.. But you are still in spec