sled head 860 or any options on 08 xp 800?

BrachtRacing16c · Aug 6, 2012

first off sorry if this subject has been covered / or if im in the wrong area
i have no clue what im am doing , i have a 2008 skidoo xp 800 146, about 2 miles on brand new stock clutches, 3500 miles on stock sled. i weigh 170 lbs, i live in nebraska do some lake and field riding i also try to take 5 to 6 trips out west a year laramie/sheridan/jackson hole/steamboat/blackhills (the old ladys trip). well the last trip of the year i un loaded the sleds took mine down the hill while every one else is gasing up my sled quits wont turn over feels locked up took plugs out and put new in starts and runs about 20 foot from trails head quits agin had them do a comp test 0 lbs in one cylinder 2 in other. i have no clue whats wrong but i would like all the power i can get, but still be some what reliable , 860 kit ? i love climbing and will try anything , would like to keep everything under $4000 if possible, i ride very hard / wide open all the time , and not easy on things . i was told to take my motor to sled heads racing in minn. i hope this gives you enough info to send me in the right direction. thanks !

ps i have no idea where this posting will go after i post it hope i can find it to see your info!?!?!?

frog · Aug 6, 2012

Give John a call, that would be the best place to start. His number is in my sig.

Visi · Aug 7, 2012

Dave Trygstads 872 would be my option.

sledsrock · Aug 7, 2012

SHR880 would be my option.

Visi · Aug 8, 2012

I do not own a BB but do have Trygstad ported cylinders. They work really well by themselves. I have been around an older Trygstad 860 with stock compression. It runs very good. It is about the same as my engine with the Trygstad porting and high compression head. His 872 is a newer design with special designed pistons. I have heard some good things about 880's and some bad things too. I know that the 880 cylinder wall thickness is getting really thin. So thin that the cylinder o-rings groves are machined into the head instead of being on the cylinders themselves. Another thing to think about is the head bolt threads. I have read stories about stress fractures inside the cylinders because the threads being so close to the inner cylinder wall. Again, this hasn't happened to me but is something I would consider when building a Mod sled. One day I will have an 872 because I will know that it's not over bored for my safety concerns and it's only 8cc's less then the biggest 800r bore out.

BrachtRacing16c · Aug 8, 2012

i gave Trygstad a call and after talking to him i feel very comfortable sending my motor there to get the 872 kit done,

anyone out there have any ideas on what else i should do to the sled
the motor build came in a little cheaper than i was expecting so i now have some extra money for more goodies any help would be appreciated

Visi · Aug 9, 2012

What year is it? I would think about putting the freeride front triangle in with the freeride post. To save a little you could get a C3 designs post forward bracket but you will have to trim your plastics a little. Just a steering update. If you are interested in suspension there are a bunch of options. I have a set of exit rear shocks for a 08-09 summit that I haven't tried to sell yet that I'm looking to get rid of. Send me a PM if you're interested. A little info about your sled and it would be a lot easier. Congrats on the engine!

BrachtRacing16c · Aug 9, 2012

its a 08 summit 800 146''
i feel i need to put atleast a 154 on the sled though, thoughts on this ?
i have the only 146 in my group the rest have 154/163's all with 08-10
summit 800's . And i never have a problem highmarking them , but would this extra power i am gaining be a waist with the 146 ???

Visi · Aug 9, 2012

Some of the best and most extreme hill climbers I know are doing it on 146" tracks. I've always been on a 150" track so I stick with it.

If you are wanting to lengthen out your sled it wont be too bad.

Track - Camo Extreme or the new Flex edge tracks are what I would choose. I hear that the Flex edge is a little lighter but it is unproven like the Camo. Not sure on eithers price right now.

Rails - I'd order Ice age 154" rails. Much cleaner looking than rail extentions
http://www.iceageperformance.com/products/rails/ski-doo-rails/2008-up-xp-slide-rails-1.html

Tunnel Extention - I would do a Van Amburg tunnel extention. I have one of their tunnels and they are great quality. I couldn't find anything that said 146 to 154 but I'd call and talk to them.
http://vanamburgenterprises.com/cat...d=267&osCsid=8511e5817968479d66398ea210d3f8f7

Hardest part of the install will be dropping the driveshaft. Sometimes the brake can be a PITA to get off. Just get some big screw drivers and lightly pry it off. Good luck!

rev_rider800 · Aug 9, 2012

BrachtRacing16c said:
its a 08 summit 800 146''
i feel i need to put atleast a 154 on the sled though, thoughts on this ?
i have the only 146 in my group the rest have 154/163's all with 08-10
summit 800's . And i never have a problem highmarking them , but would this extra power i am gaining be a waist with the 146 ???

Give BJ a call at SHR, he can get you everything mentioned. 612 718 3861

BrachtRacing16c · Aug 11, 2012

pulling the motor this weekend , hope to have the motor send off witghin a few weeks!!!

tukernater · Aug 12, 2012

You will not regret it 872 is Brute dialed in. We have been trying diffrent combo's and will be trying winter brews kit next.Congrats, Daves a great guy to deal with .I can not wait to get his new therm housing on my sleds .

byeatts · Aug 12, 2012

tukernater said:
You will not regret it 872 is Brute dialed in. We have been trying diffrent combo's and will be trying winter brews kit next.Congrats, Daves a great guy to deal with .I can not wait to get his new therm housing on my sleds .

I have several of both motors mentioned . You wont regret the SHR.

BIG JOHN · Aug 12, 2012

BrachtRacing16c said:
its a 08 summit 800 146''
i feel i need to put atleast a 154 on the sled though, thoughts on this ?
i have the only 146 in my group the rest have 154/163's all with 08-10
summit 800's . And i never have a problem highmarking them , but would this extra power i am gaining be a waist with the 146 ???

If you like the handling of the 146...a 146/16/2.5 flex edge is an easy upgrade on climbing for new motor...I have them in stock...$595 plus ship...drop gearing to 20/45 and your done

BJ

BIG JOHN · Aug 12, 2012

Visi said:
I do not own a BB but do have Trygstad ported cylinders. They work really well by themselves. I have been around an older Trygstad 860 with stock compression. It runs very good. It is about the same as my engine with the Trygstad porting and high compression head. His 872 is a newer design with special designed pistons. I have heard some good things about 880's and some bad things too. I know that the 880 cylinder wall thickness is getting really thin. So thin that the cylinder o-rings groves are machined into the head instead of being on the cylinders themselves. Another thing to think about is the head bolt threads. I have read stories about stress fractures inside the cylinders because the threads being so close to the inner cylinder wall. Again, this hasn't happened to me but is something I would consider when building a Mod sled. One day I will have an 872 because I will know that it's not over bored for my safety concerns and it's only 8cc's less then the biggest 800r bore out.

Visi...with all due respect...thats just regurgated BS from builders that are selling something else...860/872/880 wall thickness changes by .020" of an inch...with over .200" wall thickness left...oring grooves can stay if you choose...if detod hard enough it can fail in that area (just like stock)...just saying

BJ

Visi · Aug 12, 2012

BIG JOHN said:
Visi...with all due respect...thats just regurgated BS from builders that are selling something else...860/872/880 wall thickness changes by .020" of an inch...with over .200" wall thickness left...oring grooves can stay if you choose...if detod hard enough it can fail in that area (just like stock)...just saying BJ

Yes, you are right. You hear alot of different things from every builder. I have not ever ran your engines. Would I, Yes. You have a great reputation by a lot of different people. I have always had my work done by Dave and seen what his race porting and big bores can do. That's why I stick with him. I would like my O-rings to stay on my cylinder for peace of mind when installing the head. Installing a head with out cylinder head guides (Bolts with the head cut off) is a pain. The worst thing is to pinch an O-Ring. My engine is on the shelf and being a junk yard mechanic I thought I would do a little measuring for my own and anyone elses interest.

Stock bore from Skidoo says it's 82mm. I came up with 81.84 mm measuring quickly.

Distance between bolt holes and cylinder wall. 7.93mm

Distance from o-ring to cylinder wall. 3.4 mm

Measured an old Piston off the shelf too from wrist pin to wrist pin. 81.28

Engine displacement equation is

Displacement = (Pi/4)(Bore^2)(Stroke)

800R stoke from Skidoo at 75.7 mm

Pi = 3.1416

(Pi/4) = .7854

(.7854)(82^2 mm)(75.7mm) = 399773.9407 cmm = 399.7739407 cc per stock cylinder just to show it works

Re-writing the displacement equation to find the bore.

Bore = Square Root of ((Displacement)/((.7854)(Stroke)))

Taking the 872

872/2 = 436 cc = 436000 cmm

Bore = Square Root of ((436000)/((.7854)(75.7))) = 85.63471495

Bore of the 872 is 85.6 mm

Taking the 880

880/2 = 440 cc = 440000 cmm

Bore = Square Root of ((440000)/((.7854)(75.7))) = 86.02663789

Bore of the 880 is 86 mm

872R

85.6mm - 82 mm = 3.6 mm

3.6 / 2 = 1.8 mm larger from center of piston all the way around

880R

86mm - 82mm = 4mm

4 / 2 = 2 mm larger from center of piston all the way around

Also have to take into consideration the bolt threads themselves. Not sure the crest to trough on the bolts themselves.

Visi · Aug 12, 2012

BIG JOHN said:
Visi...with all due respect...thats just regurgated BS from builders that are selling something else...860/872/880 wall thickness changes by .020" of an inch...with over .200" wall thickness left...oring grooves can stay if you choose...if detod hard enough it can fail in that area (just like stock)...just saying BJ

Do you weld the o-ring grooves on the cylinders to make them flush so the o-ring in the head will sit smoothly?

BIG JOHN · Aug 12, 2012

Visi said:
Do you weld the o-ring grooves on the cylinders to make them flush so the o-ring in the head will sit smoothly?

I do weld/machine top of cylinder for a strong top edge of cylinder...the oring sits nice in domes and are machined to give plenty of room for saftey and dome alignment...if worried a little grease will always hold an oring in place...as for the previous post, good info/pics...1 word of advice...switch to snap gauges/micrometer to measure bore/pistons...always measure bottom of piston to get proper sizing...calipers OK for other measurements and use american measurements (.001")...Good luck with your new motor...XP/2.5 track/BB = :rockon:

BJ

Visi · Aug 12, 2012

Thanks for the info. I appreciate it. I'm just flipping top ends on the sleds and installing an exhaust attachment for now. :juggle:

Visi · Sep 5, 2012

BIG JOHN said:
I do weld/machine top of cylinder for a strong top edge of cylinder...the oring sits nice in domes and are machined to give plenty of room for saftey and dome alignment...if worried a little grease will always hold an oring in place...as for the previous post, good info/pics...1 word of advice...switch to snap gauges/micrometer to measure bore/pistons...always measure bottom of piston to get proper sizing...calipers OK for other measurements and use american measurements (.001")...Good luck with your new motor...XP/2.5 track/BB = BJ

Sorry for digging up an old thread. Quick question. When tigging the cylinders and adding heat have you ever experienced warping?

sled head 860 or any options on 08 xp 800?

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