Has anyone tried any aftermarket pistons in a 800cfi? I found a wiseco pro-lite double ring piston kit #SK1382. I am only considering this to avoid ecm reflash and 2010 head. I know that wiseco has believers and the opposite and was wondering if anyone knowledgable might be able to enlighten me on this. I would prefer pro-x or spi but I couldn't find anything. PS Why does this site get so bogged down and do such weird sh#@ anymore? pretty frustrating.
Wiseco pro-lite pistons in D8
- Thread starter chumbilly1
- Start date
SPI does have some available, but they made them to the same spec as Polaris so they will likely be sloppy. I am going the same route as you. I have a set sitting right here in my office. 
Wiseco specifies .0049 recommended clearance. With the new 2010 cylinders they measure .005 piston to cylinder clearance. Which is a vast improvement to the .0068 I measured on the 08 setup. They didn't even meet Polaris specifications of .0037-.0052 out of the crate. I assume you are running the older cylinders since I doubt you dropped yours on the floor. Lol Clearance should still be improved at .0056. Granted measuring out that far looses accuracy, but I'm confident that those are very close. I took numerous measurements and I am extremely meticulous by nature. The Wiseco wasn't much bigger, but much more consistent as it measured wider through most of the skirt. The Polaris piston had a very small window where it was 3.340. It measured much smaller if you were even a couple of mm off of where you need to measure. Enough to where someone could think there was a .010 difference in piston size. Hope that helps.
Wiseco specifies .0049 recommended clearance. With the new 2010 cylinders they measure .005 piston to cylinder clearance. Which is a vast improvement to the .0068 I measured on the 08 setup. They didn't even meet Polaris specifications of .0037-.0052 out of the crate. I assume you are running the older cylinders since I doubt you dropped yours on the floor. Lol Clearance should still be improved at .0056. Granted measuring out that far looses accuracy, but I'm confident that those are very close. I took numerous measurements and I am extremely meticulous by nature. The Wiseco wasn't much bigger, but much more consistent as it measured wider through most of the skirt. The Polaris piston had a very small window where it was 3.340. It measured much smaller if you were even a couple of mm off of where you need to measure. Enough to where someone could think there was a .010 difference in piston size. Hope that helps.Thanks, that is good info. Did you fit them in the 08 cylinder as well or just the 2010? I was told the cylinder is the same. What do you think of the idea of the Wiseco expanding more when warm and possibly creating a even better fit. I am leening this direction since I found out the poo pistons are not available except in kit form, and my local dealers are BO ed on the kits too . I am waiting for wiseco tech line to get back to me and tell me what I want to hear. 0.0068 is the average clearance my polaris mech buddies are reporting on the updated 08 and 09 sleds too. Forged pistons might be the ticket on these, cheaper than sending pistons or cylinders out for more coating processes. Remember the compression ? thread from last spring, these things must lose some comp to excessive clearances and the old single ring piston. Info appreciated.
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Who makes SLP's pistons? I have a 797 and had it re-nic'd to run their 727 pistons(same bore as 800 with 600 stroke). It is a 2 ring coated piston. Might be worth looking into.
That is interesting too.
The Wiseco tech told me the newer generation of pistons won't expand as much as the older ones. In the forging process they are able to utilize different materials to control this. So hypothetically you are getting a stronger piston with much more consistent tolerances. That was the sales pitch anyway. I know a lot of people swear by Wiseco so they must be doing something right.
T
theultrarider
Well-known member
That is the draw back to wiesco's if you want to call it that. It is actually human error, but we are guilty of it from time to time. You HAVE to let the engine warm up well with them or you WILL stick them. I have also broke them from det....I guess that too is my fault, but the cast pistons are more forgiving to mistakes.
4
440dart
Well-known member
well lets say you stop and walk to the area to check it out ect,ect by the time you get back you have let your sled warm up, by that time your buds are way head of ya, or if you get stuck same thing have to sit and wait, you dont have to do it with other pistons,
also how do they react with opening of the thermostat?
also how do they react with opening of the thermostat?
The cold seize worry is something that all people should be aware of with cast or forged pistons. I do really like the water temp feature on the stock gauge for this reason. How many of you are removing the thermostat? I dont understand why one would need it on these sleds. I have removed them on all my rotax motors over the last 5 years and never had a problem, but I heard some chatter about why they are more important on the CFI sleds. It seems to me that once the sled is warm having no thermostat would keep more consistent temps, rather than opening and letting a rush of cold coolant in to the head.
Those SLP pistons are Wiseco as well. In addition, I don't think those are compatible with the "new" 800s.
Well i went ahead and ordered some wiseco pro-lite 2 ring pistons. Tech says they will have 0.0049 clearance. I hope that is enough! What do you guys think. Also Who is running without or gutting the thermostat on there cfi sleds?
I think they are going to be a vast improvement. .0049 is much closer to where these should be from the factory.
Cooling vs. piston expansion
This is a subject open to debate...
On many modern deep snow machines running no stat can be ok with little or no worries because in their hunt for low weight they have shaved down the cooling systems alot.
This would not pertain to Doo or Polaris RAW chassis with their full tunnel-length coolers.
No stat obviously means no blocked cooling system from failed stat and you get the max capability to cool your sled, but I saw temps drop way low with my full lenght U-cooler in deep snow that could possibly lead to a seize. Like 80-90 deg. You want to see around 120 CONSISTENT temps.
The "cold rush" you talk about with a stat I dont see?? I've had more than one stat in a coocking pot to check opening and closing and never have I seen this on/off sort of opening/closing.
Only situation I see cold rush is the open system I run now when going from trail/hardpack into deep snow. That I've seen several times!
I'm building myself an inline housing now but running racepak with watertemp and alarm light, so if worst comes to worst I can remove the t-stat and run the open system.
My $.02
This is a subject open to debate...
On many modern deep snow machines running no stat can be ok with little or no worries because in their hunt for low weight they have shaved down the cooling systems alot.
This would not pertain to Doo or Polaris RAW chassis with their full tunnel-length coolers.
No stat obviously means no blocked cooling system from failed stat and you get the max capability to cool your sled, but I saw temps drop way low with my full lenght U-cooler in deep snow that could possibly lead to a seize. Like 80-90 deg. You want to see around 120 CONSISTENT temps.
The "cold rush" you talk about with a stat I dont see?? I've had more than one stat in a coocking pot to check opening and closing and never have I seen this on/off sort of opening/closing.
Only situation I see cold rush is the open system I run now when going from trail/hardpack into deep snow. That I've seen several times!
I'm building myself an inline housing now but running racepak with watertemp and alarm light, so if worst comes to worst I can remove the t-stat and run the open system.
My $.02
have you put your wisecos in yet? how did they do? i just bought them as well
R
R44guy
Well-known member
Piston Changes
As many of you may have seen or read the get your fix kit thread from PMS Polaris or Mountan Tek with the wiseco pistons.
I plan to have this kit done early next week but I spent some time on the phone today with Dan from Indy Specialties other wise known on the forum here as Indydan about this kit and the pistons.
Dan seen the kit as a improvement but not as he calls it the right repair. He also talked about the SPI pistons being way more cost effective and about half the price of the polaris pistons.
Dan is not impressed with the wiseco pistons since they look much weaker then the stock pistons that are very much more stout and reinforced. If compare the pistons in the picture on the pmspolaris website and see if you think the stock piston looks stronger.
Obviously we know which pistons will have better size specs and tolerances.
As many of you may have seen or read the get your fix kit thread from PMS Polaris or Mountan Tek with the wiseco pistons.
I plan to have this kit done early next week but I spent some time on the phone today with Dan from Indy Specialties other wise known on the forum here as Indydan about this kit and the pistons.
Dan seen the kit as a improvement but not as he calls it the right repair. He also talked about the SPI pistons being way more cost effective and about half the price of the polaris pistons.
Dan is not impressed with the wiseco pistons since they look much weaker then the stock pistons that are very much more stout and reinforced. If compare the pistons in the picture on the pmspolaris website and see if you think the stock piston looks stronger.
Obviously we know which pistons will have better size specs and tolerances.
Dan is not a fan of Wiseco. He had some issues with them in years past. Understandable. Dan is a very knowledgable person though. I had him do some of my motor work. When he talks........listen.
I agree that the OEM pistons visually appear stronger. They do have more reinforcement. However, the forging process actually creates a stronger material. So, hypothetically less material is needed. Plus with the more consistant tolerances the pistons aren't going to take nearly the amount of abuse that the OEM's do.
So far so good on mine, but only have about 300 miles on them. Which is more than alot of OEM pistons got I guess. Lol I do feel much more confident running these than the OEM pistons so that says something.
I agree that the OEM pistons visually appear stronger. They do have more reinforcement. However, the forging process actually creates a stronger material. So, hypothetically less material is needed. Plus with the more consistant tolerances the pistons aren't going to take nearly the amount of abuse that the OEM's do.
So far so good on mine, but only have about 300 miles on them. Which is more than alot of OEM pistons got I guess. Lol I do feel much more confident running these than the OEM pistons so that says something.
R
R44guy
Well-known member
Monte,
I always appreciate your feed back, I am glad to hear you have noticed a change with the wiesco pistons so needless to say I am going to do the fix update this coming monday right at pmspolaris in ID.
I am torn about changing out my head with the orignal style 08 polaris head or a power addiction head but I am running out of time.
I always appreciate your feed back, I am glad to hear you have noticed a change with the wiesco pistons so needless to say I am going to do the fix update this coming monday right at pmspolaris in ID.
I am torn about changing out my head with the orignal style 08 polaris head or a power addiction head but I am running out of time.
