ok, so I have an 07 summit x 800R and I have heard people talking about a mod where you add a thermostat. I was just wondering what this mod is and what the gains are from doing it?
Thanks
Evan
Thanks
Evan
07 800r thermostat???
- Thread starter evandaigneault
- Start date
http://www.dootalk.com/forums/index.php?showtopic=275664&hl=adding+thermostat
adding a 08 t-stat.
and my thread from Dootalk about adding the 06 t-stat.
http://www.dootalk.com/forums/index.php?showtopic=283153&hl=thermostat+06
adding a 08 t-stat.
and my thread from Dootalk about adding the 06 t-stat.
http://www.dootalk.com/forums/index.php?showtopic=283153&hl=thermostat+06
G
gman086
Well-known member
LOL, you're far more likely to take out your motor from a stuck thermostat than from not adding one to an '07. Biggest mistake you can make. Why do you think the '07's are stronger than the '08 and '09 800R's??? Cooler running motors = more compression.
Have FUN!
G MAN
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there is no thermostat on the 797... i wouldn't put one on...
I never saw a need to add one on my '07. Once again, the aftermarket will want to sell a thermostat kit if a sled comes without one, and sells thermostat delete kits if a sled comes with one. 
I never saw a need to add one on my '07. Once again, the aftermarket will want to sell a thermostat kit if a sled comes without one, and sells thermostat delete kits if a sled comes with one.
LOL- thats pretty funny...the delete kits for the HO motors has a 2 fold advantage, 1 being NO stuck thermostat blown motors and 2 making a little more hp from a motor running around 100 degrees...as for the 2007 the ONLY reason the cranks went early was from a poor case clearance/machine spec...the 2008 cranks are the same but a NEW machine spec for the cases...the stat on the 08-09-10's is EPA related ONLY...BJ
LOL- thats pretty funny...the delete kits for the HO motors has a 2 fold advantage, 1 being NO stuck thermostat blown motors and 2 making a little more hp from a motor running around 100 degrees...as for the 2007 the ONLY reason the cranks went early was from a poor case clearance/machine spec...the 2008 cranks are the same but a NEW machine spec for the cases...the stat on the 08-09-10's is EPA related ONLY...BJ
Well if any of you have doubts, talk to Al I am sure he would more then willing to eat crow if he were wrong. On the old forum there was a very long thread this covered this topic in detail. If you want specifics talk to the people that know.
If you ride deep/pow conditions a thermostat is required. Mostly due to increase case cooling and efficiency in the 800 r motor. If you ride ditches and trails it wont mater because you will rarely have prolonged max stress on the motor with max cooling. By this I mean hammering through pow wot for extended periods (high track speeds low sled speed) and neck deep pow where the rear cooler is always submerged in deep snow. Crank is seeing max cool while max heat is generated from the top end.
Dont shoot the messenger as I am just trying to pass along information that I have picked up. If you want the full details.
In a nutshell if you want to try to increase your life on a 07 800R motor install a thermostat. Yes your motor will last a certain number of miles but the thermostat should give you some added life.
http://www.thesledshed.ca/
They deal with the most sleds in deep snow/elevation conditions in Canada. They live/ride/test in the areas where it matters.
People that didn't have crank issues on 1000 SDI's and 07 800R's must be trail riders.
R
RKT
Well-known member
I have owned 2 07 800R's , and it is MY opinion that the stat is NOT needed..
I also ride 3-4 days a week in some of the deepest, coldest powder in the nation..
In fact, I removed the stat from my 09 800R.. No issues.. This idea that colder cooling is a negative is absurd.. Cold engine and hot pipes is the recipe for making power..
Those that are under the impression that the engine is suffering from sort of "shocking" from 90 degree coolant temps are mistaken in their reasoning. The coolant temp does not change immediately and 90 degree temps are not COLD!
Example: If you have a large open fire burning in the open on a 50 degree day.. Now, if you encase this fire in an igloo (open at the top), Has the temperature of the fire decreased? No, it has not.. Are the people outside the igloo receiving less heat? Yes..
So... Internal engine components will be receiving LESS heat with colder coolant temps.. Will they still be receiving heat? You bet.. This idea that the bearings are sitting there "freezing" due to 90-100 coolant temp is simply not true.. They are still plenty heated.. AND since when is heating internal engine parts a good thing?
Another example:
Scenario #1: You are cruising along on a hard packed road, not getting much cooling on the heat exchangers, so, your stat is certainly open and temps are RISING with every mile... Now, you dump off into 3 ft of fluff powder... What happens? Well... your HEAT EXCHANGERS, NOT YOUR ENGINE, is subjected to a cooler medium.. now, this MEDIUM, will begin apply the laws of thermodynamics and release heat and change its surface and internal temps. In this case, they will lower.. Now, this does not happen immediately, it takes some time for the new, lower, temp to stabilize... while this change in temp is occuring.. the coolant temp is GRADUALLY going lower. It is NOT immediately dropping 20 degrees. This is a gradual process... Now, we have to wait for this new heat/cooling to transfer to the cooling channels.. Then, this SLIGHTLY cooler coolant will make its way to the engine, where it willbe HEATED to a much higher temp than the cooler temp of the heat exchangers. This cycle will continue over and over ALL DAY LONG.. This is the process and always will be.. NOTHING in the engine is being SHOCKED or "Super-Cooled" when there is NO Thermostat! What does happen is that the MEDIAN Coolant Temp will somewhat stabilize and flow through the entire cooling system.. heating and cooling, cooling and heating...
Now, assume there is a thermostat installed.. same above scenario.. What is different.. NOTHING! except that the stat will sometimes partially and sometimes fully close in order to try its best to keep the coolant temp at a desired temp.. So, the END RESULT is the same process throughout the entire system but, the average coolant temp will usually be a bit higher than the system without a thermostat..
OK, now assume another Scenario (#2): You are riding in deep and cold powder and somehow... there exists some packed down hard snow
that you can ride on for some time (you know all us mtn riders love to ride the hard packed trails!So, the stat COULD BE partially closed prior to us running to the hardpacked area... Now, the stat will open all the way after some time on this nice hard trail.. Then we are back to the scenario described in Scenario #1.
OK Scenario #2 WITHOUT A STAT: What changes??? There is no stat so, obviously, we have already have full coolant flow when we get to our beloved hard packed area.. What happens? Well.. the coolant temp rises slightly due to less submerging of the heat exchangers.. So, just like the system with the stat installed.. we maintain full coolant flow and we are back to Scenario #1.
Neither system is ever shocked with hot or cold coolant. The ENGINE is NOT being smothered in snow, the heat exchangers are..
The only difference is that one system may have a slightly higher or lower average coolant temp.
Sorry for the long post..
Kelsey
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Anyone run a water temp gauge on their 07? I would be curious to see and monitor how much the coolant really changes. SLP has a sale on their 2" needle style water temp gauge for $50 with sensor. If anyone is running one of these already what does the gauge say?
In response to RKTs post. Steel expands .000057" per inch per degree of temperature change above 75° deg F. So if the crank gets 75 degrees hotter than the case it expands 0.0043". Raising the case temp to 140° lessens the temp difference. Is this possible?? Is this outside the tolerances?? That is what I was told by Skidoo was the problem with the 07' sleds, too much cooling in the monoblock case and the cranks were made to 06' specs. I love my 07' but would be hesitant to buy one that did not have a new crank with better tolerances.
'07 800R owner here with no crank issues yet and no T-stat retro-fit(2900 miles on original 800R). Anytime you want to go ride the "trails" with me Dave, you're welcome to come along
As stated many times before the problem was the center crank bearing journal was out of spec. ( too tight ) to allow for expansion. Fixed spec.= fixd problem. Have 2 07 800r's one went down at 450 miles other one is fine. Since then 4000 miles with no problems. And to talk about shocking cold to the motors we rode several times this year in Montana at 15-20 below zero and had absoutly no problems other than pissing icecicles. Believe what you want but IMHO the stat is a waste of money. By the way I have held my throttle wo for over 1.5 minutes on more than one occasion in all different temps with no problems.
...as for the 2007 the ONLY reason the cranks went early was from a poor case clearance/machine spec...the 2008 cranks are the same but a NEW machine spec for the cases...the stat on the 08-09-10's is EPA related ONLY...BJ
Thermal dynamics of metal and aluminum is irrelevant...the steel crankshaft is cradled in the alunimum case...the coolant never comes close to the steel...the crankshaft will see the heat it does no matter what...BUT the clearances between the case/crank is whats rellevant (same as piston/cylinder)...DOO had crank bearing journal clearance issues (2008 cases and 2007 replacements "R" are 10 microns bigger in the bearing area)...a thermostate wont cure poor machining...FUNNY how most of the original 2007's run for 1000's of miles, and for the ones who had issues, the replacement "R" cases have run for 1000's of miles...FUNNY how the XP's have the same crank but new cases and theres little/no crank problems (a stat wasnt the fix)-BJ
BTW- nice post Kelsey...Funny how you drove you statless XP up the trail for 5 miles then plunged into 3' of fresh snow and your motor kept running
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This debate is like Ford vs. Chevy and Demofags vs. Republibashers LOL.
No disrespect intended,
During a trip to Revy in the spring of 07, a couple friends and I met up with the boys and engineers who were showcasing the XP's (you know the ones that blew belts in 30 miles??? LOL) During a very very lenghty convo outside of Zala's with one of the BRP engineers, I was asking him about the crank issues we were seeing on the 07's. It was his opinion that yes there were crank tolerance issues but that in their testing, they also found that in certain situations, there was too much fluctuations in the coolant temps, hence the reason for the T-stat.
I'm sure there are many that never had any problems. They are the people who know what's going on with their sleds and how to ride it to avoid problems. But, unfortunately, there are peeps that have no idea and just get on it with fuel and hopefully oil and just put her to the wood. I'll bet most (90%) do not have a water temp gauge. You would be very suprised at the results if they were anything like I've seen.
I think it's a good thing BRP added the T-stat for the XP's. It makes the engine more dummy proof. Why not have an engine running a more consisitent temperature?
'07 800R owner here with no crank issues yet and no T-stat retro-fit(2900 miles on original 800R). Anytime you want to go ride the "trails" with me Dave, you're welcome to come along
Cool. Thanks for the invite. Always willing to ride with new peeps.
