850 patriot
- Thread starter damx
- Start date
It’s a cool motor, crankshaft is the same length as the small block 800
All the gains were pulled from shortening the Mag end of the crank & widening the center
And just a touch more stroke. Pretty amazing for its size.
The 840 motor screams louder then the 800
don’t big bore me.
Polaris stretched this thing for just about every once it has at sea-level with a single pipe.
Pretty impressive motor for its over all length.
Dan
All the gains were pulled from shortening the Mag end of the crank & widening the center
And just a touch more stroke. Pretty amazing for its size.
The 840 motor screams louder then the 800
don’t big bore me.
Polaris stretched this thing for just about every once it has at sea-level with a single pipe.
Pretty impressive motor for its over all length.
Dan
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Did you notice the squish area? If we cut-out the roll-over on the Ski-Doo 850 they would be nearly identical at around 58%, whereas the Arctic Cat 600 C-TEC2 is a whopping 68% (I haven't checked the 800). Now add the single ring and air hole, it's venturing even closer to a Ski-Doo
I'm just messing around and in no way suggesting any copying, but it is interesting to see the similarities as tech progresses.The crankshaft is the tricky part. The difference in price is going to be (cough) huge. And what do you do if the journals on the 2 piece cranks get damaged/worn? What happens if the crank runout is too high? By the way, how many pieces is the Patriot, 4 or 5?
You got to love the elusive 9% gain we kept hearing about. At first it was rumored to be a 9% gain over the Polaris 800 HO, which made no sense. It turned out to be a 9% gain in power to weight ratio over the Ski-Doo MXZ 850 ETEC trail sled, and 7% over the Ski-Doo Summit 850 ETEC.
Since Ski-Doo is the only 2S with DI, I say good for Polaris to find an upper hand on their competition.
Did you notice the squish area? If we cut-out the roll-over on the Ski-Doo 850 they would be nearly identical at around 58%, whereas the Arctic Cat 600 C-TEC2 is a whopping 68% (I haven't checked the 800). Now add the single ring and air hole, it's venturing even closer to a Ski-Doo
The crankshaft is the tricky part. The difference in price is going to be (cough) huge. And what do you do if the journals on the 2 piece cranks get damaged/worn? What happens if the crank runout is too high? By the way, how many pieces is the Patriot, 4 or 5?
You got to love the elusive 9% gain we kept hearing about. At first it was rumored to be a 9% gain over the Polaris 800 HO, which made no sense. It turned out to be a 9% gain in power to weight ratio over the Ski-Doo MXZ 850 ETEC trail sled, and 7% over the Ski-Doo Summit 850 ETEC.
Since Ski-Doo is the only 2S with DI, I say good for Polaris to find an upper hand on their competition.
Can you tell us your source for the bold part of your quote? Or is it just an educated deduction on your part? Not denying you're accurate just haven't heard this before.
RMK-King
Super-Moderator
I'm not familiar with the skidoo comparison.
I was told directly from Polaris engineers behind closed doors that it's 9% over the Polaris 800ho.
There were several of us in the room...I wasn't hearing things.
I will provide the source video timed @ 56s and the text that I wrote from the video. But as RMK-King showed from the literature the Patriot also has a 9% Power gain over the Cleanfire 800 HO. I thought that we checked in another thread and it was closer to 6% gain, but then again those were Hp numbers provided to the EPA.
"Power. The Polaris 850 Patriot is the most powerful engine Polaris has ever produced. And yes it has class leading power, power to weight.
The Polaris 850 trail sleds are 9% better in power to weight versus the competition. And Polaris 850 mountain sleds are massive 7% better in power to weight versus the competing 850 mountain sleds. Translation, more power and far less weight wins.
Inertia. The Polaris 850 Patriot has 13% less rotating inertia than the yellow 850. Revving up that much quicker is quite an advantage, from the hole shot to creating instant lift in the power. And acceleration, this engine is the definition of acceleration. You are just going to have to ride it to feel what this means."
https://www.youtube.com/watch?v=b5wIPhOqcJo&t=0m56s
It was my mistake. I should have found the Polaris literature before making that conclusion. I assumed that it couldn't be both 9% gain in Hp over the 800 HO and also 9% gain in Power to Weight with the Ski-Doo trail sled. But indeed it was. I have to say that it is a surprising gain over Ski-Doo, but like I said earlier all the better for Polaris and it's good for competition.
I figured this motor was going have an overall longer crankshaft
To get the needed width to increase air flow.
Which would have made the axys feel much heavier.
But robbing length from the MAG end and putting in the center of
The crank was brilliant.... then narrowing up the front suspension makes the small weight gain with the added power should put the Axys 840 at the top of the performance list for a few years to come.
Big bored & porting to this motor will be hard pressed to gain anything without dependability losses.
This motor was well though out.
It has a 4 peice crankshaft with separate rods pins
( Not incorporated into the inner wheel like the 800 )
This has good and bad features....
Good - easier & cheaper to manufacture.
Bad - harder to Tru..... and easier to knock
Out of tru when blowing a belt.
It’s a beast of a crank ( huge rod pins, and huge bearings )
Only time will tell dependability..... Mathmatics are more of a factor
Then just using huge parts.
The great part is it’s an easy crank to service and make replacement parts for.
Also should be a great Turbo motor.
This motor would be a real challenge to be out performed by another OEM.
It’s short crankshaft length is pure brilliance for a
mountain sled.
I would say it’s the most brilliant 40cc gain I have ever seen.
This reinforces why I was always against Big boring the
800 Small block.
It took Polaris over 5 years & an almost unlimited budget to
Find a magical 40cc’s without hurting handling to much and huge
power per CC
In today’s platforms big bores & porting is a slippery slope.
I guess in this early stage it just seems like a great move
Into a new motor.
To get the needed width to increase air flow.
Which would have made the axys feel much heavier.
But robbing length from the MAG end and putting in the center of
The crank was brilliant.... then narrowing up the front suspension makes the small weight gain with the added power should put the Axys 840 at the top of the performance list for a few years to come.
Big bored & porting to this motor will be hard pressed to gain anything without dependability losses.
This motor was well though out.
It has a 4 peice crankshaft with separate rods pins
( Not incorporated into the inner wheel like the 800 )
This has good and bad features....
Good - easier & cheaper to manufacture.
Bad - harder to Tru..... and easier to knock
Out of tru when blowing a belt.
It’s a beast of a crank ( huge rod pins, and huge bearings )
Only time will tell dependability..... Mathmatics are more of a factor
Then just using huge parts.
The great part is it’s an easy crank to service and make replacement parts for.
Also should be a great Turbo motor.
This motor would be a real challenge to be out performed by another OEM.
It’s short crankshaft length is pure brilliance for a
mountain sled.
I would say it’s the most brilliant 40cc gain I have ever seen.
This reinforces why I was always against Big boring the
800 Small block.
It took Polaris over 5 years & an almost unlimited budget to
Find a magical 40cc’s without hurting handling to much and huge
power per CC
In today’s platforms big bores & porting is a slippery slope.
I guess in this early stage it just seems like a great move
Into a new motor.
Great write up!
Does that guy even sell snake oil still?
It didn’t work in 03 when my buddy tried it.
Still didn’t work in 05 when I tried it.
Got worse in 13 when a local shop up here tried it. (Spanked by a stocker after 100 miles)
There’s really only one guy/shop who will work on my Polaris engines.........
(And it’s not me)
