XP big bores - lets compare

[Original Tetonice]

OT-What is it that goes/wears that makes the compression go down? Rings, poor nikasil that wears off, cyl too thin and goes out of round, the crank, termites eating through the domes.....? What is it with these BB's that they have to be rebuilt so often? I am very confused why you say what you say. Is this personal experience with these mods? Are you an engine builder/engineer in the know , just trying to figure out where all your knowledge on engines (and clutching) comes from.
These posts that are intelligent and informative have been screwed by people that are bound and determined to prove that they know something. I enjoy these posts and don't understand why they always have to go down this road. Sorry if I come off offensive, I am not normally.

"It is better to be quiet and be thought a fool than to open your mouth and remove all doubt"........the ramps in a tra do not move.

Flame away

While Joe is dodgeing the questions ......This one is real simple "HEAT"....It' pretty simple folks. 2 Stroke Get Very Hot. Touching points like your piston & rings as they cycle Up & Down the cylinder walls making compression will get very very hot. Every time you start and stop your sled the engine expands and contracts slightly at every cycle. Cold morning start up can be the harshest on your cylinders, ring & piston ....Also not allowing your coolant to cycle and cool your motor correctly is very bad on touching engine parts as well. Your light weight metal motor expands and contracts " MOVEMENT " just like those TRA ramps Joe & BJ.

Here's a question....How many of you guy's stop and hit the kill switch right away without allowing your coolant to cycle for a minute or two ?

Heat is the problem between the cylinder and ring and piston and can be the primary reason compression can be down. Doing a fresh "top end" is normal and similar to maintaining your clutch. Keeping a fresh top end in your expensive BB kit is cheap insurance just like running good quality octane to match the compression of your motor.

I own and have owned many BB kits both Poo and Doo & turbo Yammies. I know what they cost to build, I know how there built, and iI no what to cost to keep running correctly.

OT

 

[winter brew]

While Joe is dodgeing the questions ......This one is real simple "HEAT"....It' pretty simple folks. 2 Stroke Get Very Hot. Touching points like your piston & rings as they cycle Up & Down the cylinder walls making the compression get very very hot. Every time you start and stop your sled the engine expands and contracts slightly at every cycle. Cold morning start up can be the harshest on your cylinders ....Also not allowing your coolant to cycle and cool your motor correctly is bad as well. Your metal motor expands and contracts " MOVEMENT " just like those TRA ramps.

Here's a question....How many of you guy's stop and hit the kill switch right away without allowing your coolant to cycle for a minute or two ?

Heat is the problem between the cylinder and ring and piston and can be the primary reason compression can be down. Doing a fresh "top end" is normal and similar to maintaining your clutch. Keeping a fresh top end in your expensive BB kit is cheap insurance just like running good quality octane to match the compression of your motor.

I own and have owned many BB kits both Poo and Doo & turbo Yammies.

OT

So....by your theories, wouldn't a bigger bore last longer with the additional surface area/contact area of rings and more area for heat dissipation??....not to mention most of the bigbores go to 2 rings vs the stock 1 ring. The temps are the same whether a 440 or a 880 so wouldn't bigger=longer lasting in OT-land ?

 

[BIG JOHN]

In ideal conditions @ 9000' your stock 150 HP sled will produce 115 HP +/-

In ideal conditions @ 9000' your 170 HP BB will produce 124 HP +/-

Simple math

OT

LOL..YOU cant even DOO that...

Stock 800R @ 150 hp X 25% HP loss = 112.5 HP
My SHR860R @171 hp X 25% HP loss = 127.5 HP

The 600 mountain sleds make 125 hp x 25% loss = 93.75 hp

According to ice...theres no difference from a 800 motor vs a BB kit...BUT I bet his 800 KILLS a 600...LOL-BJ

BTW- "A" in TRA is for adjustable...not movable...your sled does not have a TRM on it does it??...LOL

 

[Insaneboltrounder/sjohns]

You guys really need to try out the ignore feature in here. I undid it for a while and got a nasty headache reading dippsheets bull. Clueless he is , common sense isnt all that common in his house. sj

 

[Original Tetonice]

So....by your theories, wouldn't a bigger bore last longer with the additional surface area/contact area of rings and more area for heat dissipation??....not to mention most of the bigbores go to 2 rings vs the stock 1 ring. The temps are the same whether a 440 or a 880 so wouldn't bigger=longer lasting in OT-land ?

Good Question..imo No because the touching points remain the same regardless of the bigger bore, piston, 1 ring or 2 ring it still must grad cylinder wall. Metal on Metal = Heat

BJ, at 9000' did you not see the plus/minus ? I also calculate X .03% per 1000 feet... M in Ramp means moveable

OT

 

[Original Tetonice]

According to ice...theres no difference from a 800 motor vs a BB kit...

Your full of BS BJ Show ma the post where i said that ?.......what i did say a BB can put a smile on your face or an unhappy smile on your face....Just ask DaveB is he happy with his BB kit ? Im happy with my Trigstad BB.

OT

 

[Original Tetonice]

You guys really need to try out the ignore feature in here. I undid it for a while and got a nasty headache reading dippsheets bull. Clueless he is , common sense isnt all that common in his house. sj

Im 100% certain you hit your kill switch right away when you stop your sled.

OT

 

[Insaneboltrounder/sjohns]

Lookey that... 3 post from the babbling moron and all I here is peace and quiet.... that ignore button is SWEET I tell ya !

 

[Original Tetonice]

Lookey that... 3 post from the babbling moron and all I here is peace and quiet.... that ignore button is SWEET I tell ya !

2 post from you and the same old useless info.... It pretty clear this discussion is over your IQ level

OT

 

[gus bohne]

HEY,

I just tried the ignore button,,, All the babbling went away..lol





Yes, the larger surface contact area of the bigger bore piston increase's the heat transfer RATE.

Funny thing John, the RS has no thermostat, in heavy wet snow conditions like we had these last few RMR and ISOC events the biggest issue was loss of temp..

by lap 3 we saw engine temps DROP to under 88 degrees !!
This was causing some teams to experience a low end bog off turns due to LACK of heat in the engine and pipe..COLD BOGS..damn !

Even Jason Boron who won the last events pro open final came off track and had coolant temp of 84 degrees after 16 laps ! The coolers were freezing cold to the touch..

NOW if the rules allowed we could have used a t stat in the stockers,, IF that was allowed..


Gus

Bj/Joe Tntm7... you guys are good ones..too.

 

[Insaneboltrounder/sjohns]

Isnt it great ! If that clueless blow hard had even posted 1 useful thread Id maybe kept him on... but nope. He is the typical internet dork that loves to see his babble in print. I hear he takes his sleds to a shop to get anything other than a belt changed. No thats just pitiful. Tho RTK , BJ , TNT and the rest... thanks for the great info. To OT..... keep spouting the BS , fewer and fewer are having to hear it

 

[Original Tetonice]

Gus Bohne, It must of been "bone cold" where you were racing for your heat exchangers to freeze. Keeping the pipe hot must of caused performance issues that weekend as well.

Wet heavy snow, freeze thaw & up and down temps can make tuning a headache at the race track

OT

 

[Dynamo^Joe]

Hey Gus, nice to meet you here. Heard a lot of you over the years regarding triples and "finger ports" seem to be a common comment about happy race engine owners.

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---------------Ahhhhh, what a neat feature.-----------------

Big John was mentioning some stuff about elevations.....

I ran this by RKT and TurboAl before

This chart is from Globalspec, they make Kollsman-type barometric aircraft altimeters.
Quote - Knowing atmospheric pressure decreases with altitude in a very regular fashion...
Neglecting moisture and temperature this is kind of a standard chart can be formed.

100% @ 0000' elevation
89% @ 3280' elevation
78% @ 6560' elevation
60% @ 9850' elevation
56% @ 13120' elevation
53% @ 16400' elevation


Could this guideline be followed regarding horsepower on a skidoo summit engine? Which chart would be correct?

If an example summit engine had 150 hp at sealevel then can the chart also be applied to hp values?


100% @ 0000' elevation [150hp]
89% @ 3280' elevation [134hp]
78% @ 6560' elevation [117hp]
60% @ 9850' elevation [90hp]
56% @ 13120' elevation [84hp]
53% @ 16400' elevation [80hp]

or is it a percentage of the remaining value of horsepower?

100% @ 0000' elevation [150hp]
89% @ 3280' elevation [136hp]
78% @ 6560' elevation [121hp]
60% @ 9850' elevation [102hp]
56% @ 13120' elevation [91hp]
53% @ 16400' elevation [86hp]

 

[Original Tetonice]

Sealevel HP X .03% per 1000 feet determines the correct altitude HP. Some guys use .04% per 1000 feet... And yes other factors associated with high alitudes can add a +/- to the actual corrected HP.

OT

 

[winter brew]

air density gauge -

 

[Insaneboltrounder/sjohns]

Too bad there isnt a density gauge for some of the swest posters

 

[gus bohne]

Joe, thanks for the kudo's..

I wondered now for years when using corrections in the dyno room , Why we did NOT use airbox air temps rather than ouside ambients..

We did input that way during a session in on my 1990 rxl turbo, the figures are grossly overexagerated but it does SEEM to me it would be more accurate..

The engine IS using it at the elevated temp,, therefore would the output not be effected by it ??


food for thought..


I really get great pleasure from helping people..

 

[Xrider]

And don't forget, the guys in Canada use metric horsepower!!

 

[fatguy1]

air density gauge -

I have one I use for drag racing and I take it with me in the mountains just for the fun of it.

Last time out at the parking lot with temp around 30 F at 2400 feet my gauge was showing 96% once up at 9500 feet and a little cooler temp the gauge was showing 78%. I'm thankful to DPM cause that would have been a lot of jet changes in the good old days.

 

[Slick]

Too bad there isnt a density gauge for some of the swest posters

Great thread, but in reading it, gotta say OT at least thinks he's contributing, good or bad, I can't really say. But you, you're almost as annoying with your babble, and you're not contributing squat.