Long stroke as compared to the old 600 and the new 700 @ 70MM. Looks like the stroke is the same as the new 800 and it has TM40's.

Engine Model Number S3577-6044-PU6J
CC’s, Cooling, Cylinders 599
Bore & Stroke (mm) 73.8 x 70
Carburetion 2 TM 40
Oil Injection N/A (pre-mix 32:1)
Alternator Output 170 W
Ignition Digital
Cylinder Plating NiCaSil
Exhaust Polaris VES, Single Pipe
Minimum Fuel Octane 92
CLUTCHING/GEARING
Drive Clutch P-85
Drive Clutch Weight 10-58
Drive Clutch Spring Almond/Red
Center Distance (in./cm) 10.625
Driven Clutch Type Lightweight TEAM™ Roller
Driven Clutch Helix (70/44-46)66/44-46)
Drive Shaft Sprockets 9T Slip Race Design

Your information is interesting. It looks like people were right when they said the engine would have a longer stroke.

Why are there 10-58s in the primary? Don't the stock 600 IQ consumer models have 10-60s or 10-62s in them? I believe the 10-58s are stock in the older 600s ...

The 07 600 CFI comes with 62's, not 58s. The older 600s came stock with 58's or 60's, depending on the year, and almost always had to be changed to load the engine properly when clutched.

It appears I'll be the proud owner of a "08 IQ600 race in April. I'm very interested in this new motor. Performance, adapting the 797 cylinders, etc. Please keep the info rolling.

See if they'll let you pick it up early Greg. Bring that bad boy up to the Keweenaw for some late season action.

Interesting that they went to a long stroke on that motor. There may be something to that...FWIW, all 250 2stroke motocross bikes have long strokes and small bores. Most are around 72mm, and will still rev to 9000 rpm. What is Polaris claiming that motor will put out, HP wise?

I haven't heard any official claims, but in race trim it should be in the 128+ range. Part of the advantage of the smaller bore and longer stroke is more effective cooling, which allows for more compression and hotter ignition timing.

I have very good inside source info that the stock motors for the racers on 110 race gas are closer to 140.

well if it is in stock form the motors have 92 octane heads and can't run 110 in stock class, and them claimed at haydays to have 132 hp

the compression is capped by isr but its not full stroke compression its figured the other way I beleive. Would the longer stroke allow them to exploit this somehow? Engine gurus help me out I am not sure how to figure this but I have a suspision this is what they are doing but maybee I am on crack.

I've also heard claims of "high 130s" for HP, but was also told by a knowledgeable racer that he realistically expects it to be in the "low to mid 130s". There could be some trick Polaris is working with the rules and the long stroke, but I suspect they're really after the conventional benefits of a longer stroke motor. Longer stroke = more torque (and potentially more HP). Smaller bore = more room in a given cylinder bore centerline for large transfer ports - helps the cylinder breathe efficiently.

It appears that the connecting rods are interchangable with the new 800. I wonder if this motor was just waiting for the 440 to die- now Polaris has the luxury of making a small bore (600) from the new 800 small block. Let us know what you find out AFJ.

I'm getting a little info. This motor is very interesting. Enormous potential.

Do you know who designed the motor?

You're talking corrected compression ratio. It only takes into account the stroke of the piston above the exhaust port...because the engine cannot really build compression before the exhaust port closes...pulses from the pipe not included.

My mistaken on the 110 octane... I misunderstood what my friend told me. The new sno-cross motor will run on 93, but the race teams will run 100 octane for safety factor. In the stock form that runs on 93, they are dynoing around 135. It would be fully trailable like this, and with mods would easily be much more potent than the old motor!
Unfortunatly, they are not using this motor this year for the mod sleds as they have not had enough time to develop the porting, pipes, etc to make the most out of them... So they will use the older small block 600 motor again, it still makes more power than any of the other ones modded anyhow. 160 hp, on 112 octane, with SLP stamped pipes (moded of course).
Should be interesting...

Hope I have enough money next year to pick up a used race sled.....

So is this a 800 with a different top end? so you could put 800 dragon jugs on it?

What is the operating RPM of the motor?

Those motocross bikes have no need to run at sustained 9,000 rpms either..but from what i've been told the decision is also a good one..not only can more power be squeezed but when they cfi this motor... the mapping can be more precise for better fuel economy....its a win win.

Correct. The short stroke small block has been maxed out for porting potential in the 600HO. The longer stroke gives more options. It's the same bore x stroke as the F6 which has a slightly shorter stroke than doo's 600HO.

Maybe they got that old German dude out of retirement. What was his name, Hendricks? Didn't he come from Kohler or something?