What Makes the 800 down on Power? (lots of 2 stroke info)

[RKT]

Well...it really says alot that you dont know where you said polaris 800 was 150 hp stock...why dont you look at your website...i was interested in buying some of your stuff...until i realized you show no dyno charts or even hp numbers with yout polaris big bore kit...only said it is cheap...which indeed it seems

Since your website is made for 2 stroke heads...you should know an offset combustion chamber to the intake side evens out the heat inside the cylinder and the intake charge is cooler because its away from the exhaust side

Now where did i say i havnt seen this engine? I said i didnt really look and measure specs of this motor before

Now are you looking for piston dimensions or clearence between the cylinder wall? These are different things here...

We all love Alter Egos... Should we guess who you are?? I have a pretty good idea.. but you keep on with the facad.. it will be good fun

Offset combustion chamber on a loop scavenged engine.. LOL... Better go back and study your books some more... Intake charge away from the exhaust with an offset chamber.. WOW!!!

The chamber is not in play when you are "intaking" ... the piston is at BDC....

So, how do you keep the intake charge away from the exhaust??.. you splitting the cylinder?? LOL
This just keeps getting better and better.. Maybe you have one of those offset cranks also???

Too agressive exhaust valve?? LOL.. that is a good one!! So I guess you can get more "fully open" than " fully open" Is that what you mean?? So when you are past fully open, then you are too agressive... right?? good to know.

[Porting, I have no idea of what the ports inside this motor look like,

Aah.. above is where you state you have not seen inside this engine!!

anyway, you keep up with the total BS-ing of people.. maybe discredit AAEN and myself some more..... that seems to be working for ya...

Seems Bikeman sure gets mentioned in most of your posts... hmmmm

WOW!!!

 

[AKSNOWRIDER]

I don't know about the thickness issue on the stock cylinders, but here is a picture comparing a 910 cylinder to stock, 910 looks pretty thin to me

Brad"s 910 is a long rod motor if I remember right, lengthening the rod takes most of the load off the piston walls.

 

[907assault]

RKT,

Why is it that in every thread I see you in, you're full of controversy and drama?

We're all people here looking to better our sleds and help each other.

Keep it simple

 

[AKSNOWRIDER]

For those who are really interested in learning more about building hipo engines(doesn't matter, 2 stroke/4 stroke/ diesel, 1 cylinder to 20, this book is a great read and will really help you understand the dynamics of a engine..including block stiffness, rod ratios(both mechanical forces and how it alters port flow/volume), how port volume/flow/design all interact in relation to HP/torque and rpm... its old..but still 100% applies, the man who shares the info is by far and away one of the premier engine builders to ever touch a wrench to anything...

http://www.amazon.com/Chevrolet-Racing-Engine-Bill-Jenkins/dp/0931472016

 

[RoffRider]

We all love Alter Egos... Should we guess who you are?? I have a pretty good idea.. but you keep on with the facad.. it will be good fun

Offset combustion chamber on a loop scavenged engine.. LOL... Better go back and study your books some more... Intake charge away from the exhaust with an offset chamber.. WOW!!!

The chamber is not in play when you are "intaking" ... the piston is at BDC....

So, how do you keep the intake charge away from the exhaust??.. you splitting the cylinder?? LOL
This just keeps getting better and better.. Maybe you have one of those offset cranks also???

Too agressive exhaust valve?? LOL.. that is a good one!! So I guess you can get more "fully open" than " fully open" Is that what you mean?? So when you are past fully open, then you are too agressive... right?? good to know.



Aah.. above is where you state you have not seen inside this engine!!

anyway, you keep up with the total BS-ing of people.. maybe discredit AAEN and myself some more..... that seems to be working for ya...

Seems Bikeman sure gets mentioned in most of your posts... hmmmm

WOW!!!

i guess you dont under stand or what...

i dont know if you know this...but the hot side of the piston and cylinder is the exhaust side...and when you have a squishband set up like this about half of the piston area, and on the cooler intake side...you even out the heat across the piston...its amazing you actually get by and make products like cylinder heads...too agressive exhaust valve spring is what i should have said...my bad, forgot i need to explain stuff xtra for some peope...while i have not seen inside this engine...im pretty sure once mine runs out of warranty im not leaving it stock

 

[Norway]

RKT,

Why is it that in every thread I see you in, you're full of controversy and drama?

We're all people here looking to better our sleds and help each other.

Keep it simple

In THIS thread I would have to disagree. Mr. newguy RoffRider comes along pretty insulting when he talks down someone who is actually making a living selling performance upgrades.

And RoffRiders writing clearly states that he has read a book or two but not much else. This shows in his lack of knowledge about why the poo head (and every two-stroke snowmobile sold the last 40 years) uses the centered dome design.

Also, the difference in porting and injector placement between a CFI 2 and a CFI 4 is considered pretty basic knowledge... It's been all over the polaris adds when they changed it.

RoffRider: Take it easy, read some more here and do more research on modern two strokes. You can always insult people later..

 

[RoffRider]

lol rk tek

on your 2 stroke head for the 800 is shows a dyno sheet saying stock pro is 138 hp

so is it 138 or 150? 12 hp is a pretty big difference

you mind telling you customers that even though you knew the polaris motor was lower than 150 you still tried to say it was 150 so you can assure your customers you can get a higher for-sure hp with your big bore kit?

 

[RoffRider]

In THIS thread I would have to disagree. Mr. newguy RoffRider comes along pretty insulting when he talks down someone who is actually making a living selling performance upgrades.

And RoffRiders writing clearly states that he has read a book or two but not much else. This shows in his lack of knowledge about why the poo head (and every two-stroke snowmobile sold the last 40 years) uses the centered dome design.

Also, the difference in porting and injector placement between a CFI 2 and a CFI 4 is considered pretty basic knowledge... It's been all over the polaris adds when they changed it.

RoffRider: Take it easy, read some more here and do more research on modern two strokes. You can always insult people later..

well ive only researched the cfi2 on hcs...i would have came here but i would have had to register...which i did not too long ago...and if you give me a link to where polaris show the injector location, and where it is pointed...that would be great...if you can tell me why every snowmachine in the last 40 years uses the center chamber design then i will drop the topic

also if you have an exact port map of the pro motor...post it up...please

another one...bruce at PSI sells this stuff for a living...is it bad when people talk him down? i dont like salesman who lie...sorry if that makes you feel bad...but when im spending thousands of dollars on a bigbore kit i would like to know some info that isnt stretched

 

[wfieldin]

RKT,

Why is it that in every thread I see you in, you're full of controversy and drama?

We're all people here looking to better our sleds and help each other.

Keep it simple

X2.........Sometimes less is more!

 

[xmk1080]

i guess you dont under stand or what...

i dont know if you know this...but the hot side of the piston and cylinder is the exhaust side...and when you have a squishband set up like this about half of the piston area, and on the cooler intake side...you even out the heat across the piston...its amazing you actually get by and make products like cylinder heads...too agressive exhaust valve spring is what i should have said...my bad, forgot i need to explain stuff xtra for some peope...while i have not seen inside this engine...im pretty sure once mine runs out of warranty im not leaving it stock

Just curious but wouldn't this offset combustion chamber load the intake side of the piston more upon combustion, causing the piston to rock more which is or was a big problem on the '11 and '12's?

 

[rmscustom]

This thread started out pretty informative but its obvious roffrider has a hidden agenda and a possible alias and we all know Rkt wont back off... Play nice kids.

 

[Reg2view]

....and if you give me a link to where polaris show the injector location, and where it is pointed...

Before the mods lock this thread up...

You've asked for this three times. While you now admit you've looked at the motor, but just not measured it, and you just keep asking. WTF, just being rhetorical, can't find an injector when you looked, or ???

Time to put this thread on ignore. Flashback to those tetonice dayz...

 

[RKT]

lol rk tek

on your 2 stroke head for the 800 is shows a dyno sheet saying stock pro is 138 hp

so is it 138 or 150? 12 hp is a pretty big difference

you mind telling you customers that even though you knew the polaris motor was lower than 150 you still tried to say it was 150 so you can assure your customers you can get a higher for-sure hp with your big bore kit?

LOL...

Well, I will induldge you one more time with some answers (which you will not answer anything that is asked of you) before I leave this rediculous thread.. I think people can see what you are doing and how you are just trying to stir up trouble.

1) The dyno sheet on my website of the stock engine is an engine with some miles on it and the SAME dyno shows tha CAT HO at 145HP..

So, do the math.. CAT 145 Polaris 138.. 7HP difference.. which is what I see as well with testing.. On other dynos The Cat comes in at 157HP.. Hmmm 157-7= ???? So is the CAT really 145HP?

Dynos are just a TOOL.. the final number is NOT important.. what IS important is the "delta" or difference in output power when you add a performance part (or 2 or 3).. This is how you determine of the part is effective...
Every dyno , due to calibration, can and read different but the "delta" should remain constant if the dyno is properly calibrated..

Bell's book.. figured as much...Great book.. Keep on reading..

Offset chambers were used in the the 60's and 70's for various reasons.. Mainly because 2 stroke development was in its infancy..

The offset SQUISH STYLE chamber (quite different from an offset chamber.. proper terminology is critical) was never effective at making any power.. Its purpose was to keep the, then ,crude, pistons design and materials from seizing... This kept some heat down on AIR COOLED ENGINES!!! because nobody had a water cooled 2 stroke engine in those days and the air cooled engine heats up very quickly and has a less effective means of dissapating the heat...



They quit using this chamber in the late 70's very early 80's (or therabouts) because they found it caused massive power loss and promoted detonation. AND they started making WATER COOLED 2 STROKE ENGINES...

Yup. technology advanced and the old technology (offset chambers) was gone like wind...

We rework many of these heads on the vintage cycles in order to gain performance... It is incredible what changes when you get rid of that design..
Just think if Poalris would only read Bell's book how much better their engines would be?? they must not know about it..

Book reading is great.. but having the experience to apply the material read.. well.... that is something you can't learn from a book...

Have fun..

 

[RKT]

RKT,

Why is it that in every thread I see you in, you're full of controversy and drama?

We're all people here looking to better our sleds and help each other.

Keep it simple

Ya know.. I can see how it may appear that way..

But if you look closely, you will see that I never disrespect anybody or result to dorrogatory remarks...

Actually, I am here to help you guys...

I have never seen an engine that has so much mis information surrounding it.. From offset cranks, offset cylinders, bad rod ratios, heat soaking of the engine to the point of cold seize.. the list goes on and on..

Information is a great thing and the internet allows for this information exchange.. What the internet also allows for is total falsities being posted about any and all subjects..

Again, I have never disrespected anybody on this forum or any other..

I am here to help you guys sort out the incorrect information that surrounds this engine..
Providing pure technical, hard ,and REAL data is all that has been done on my behalf..... What you do with the data is entirely up to you.

There are never any sales pitches or anything of that nature associated with my posts. Just information, which is what these forums are based upon.. are they not? Please do not read into any of my postings words that are not there.. I call it like I see it.. no hidden meanings.. just technical information that you can use or discard.. your choice..

If you feel that, me, providing this hard and real data on your behalf, is dramatic, then that is unfortunate..

It should be controversal because with ALL information, including the info I provide, there should exists some hard data to support it .. NOT just some "because so and so told me so" data, but REAL data...

Everybody should be asking "Where do you get your information to support your statements" Everybody..

Just trying to help.. that's all.. sorry some are offended...

 

[RoffRider]

Before the mods lock this thread up...

You've asked for this three times. While you now admit you've looked at the motor, but just not measured it, and you just keep asking. WTF, just being rhetorical, can't find an injector when you looked, or ???

Time to put this thread on ignore. Flashback to those tetonice dayz...

Ive never ripped this engine out of its chassis or did anything under the hood besides add oil...

 

[RoffRider]

alright rkt...that post made sense...my bad for calling you a liar

 

[Jaynelson]

Big thanks to AK for posting some stuff worth reading in this trainwreck....

 

[AKSNOWRIDER]

I am curious why people don't stroke the crank on these motors.

Jeepin, stroking a pro would be tough..its really hard to visualize, but when you stroke a motor you move the rod pin farther away from the crankpins(thus moving the piston further up the cylinder as well as further down the cylinder(moving more air per stroke)but, as the crank moves from TDC to BDC the rod pin ends up farther from the center of the cylinder bore..so at 90* from TDC(or BDC) the angle of the connecting rod from the piston pin to the crank rod pin ends up steeper(this with the same stock rod length). This steeper rod angle expotentially puts more load on both the piston and cylinder..not good in a motor already having piston/wall load issues...
conversely, a common mod is running the same stroke but add a longer rod(this is altering the rod ratio) this does take load off both piston and cylinder. but when altering rod ratios it also has an effect on how the motor breathes(all engines are air pumps..the more air they move..the more power they make) so modding rod ratio requires looking at everything, mechanical issues/ breathing issues/ tuning issues caused by a "simple ratio change". not something for someone to mod without knowing what they are doing and spending a lot of time retuning everything to take advantage of it..
Now I built my first hipo small block when I was 16.. A very very wise racer gave me a good piece of advise...the key to a great motor is in the boring parts..block/heads/crank..and no matter how much you spend on the bells and whistles" the motor is only as good as the boring parts..in other words, the pieces you take for granted, block, crank, cylinders decide how good a motor is..both in power and reliability.

 

[RED995]

Quite the thread, some good info for sure. Couple things I know for certain is one lifting the cylinders on this engine and getting the cylinder skirts out of the crank case is going to change two things. Its going to increase case volume and remove a restriction both of which will have a positive affect on hp. Two by using a piston with a lower pin location is going to take pressure off the rings and evenly spread it down the skirt of the piston and its going to take rock/slap out of the piston in the cylinder which will have a positive affect on the longevity of these engines. Depending on how high the cylinder is lifted and what piston configuration is being used, it will also provide more positive porting options. Feel free to contact me for more info as we will be building this engine this year 780 986 6370 or pm me here.

Thank you

Deano

MAD MOTORSPORTS

 

[mngoat]

Ive never ripped this engine out of its chassis or did anything under the hood besides add oil...

Sounds like a good sled to me then. Why are you worried so much about the power????