Easier to Just call Dan.
Riding out the Earthquake
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Easier to Just call Dan.
Hey you 900 Polaris guys check out the thread I posted on " all polaris" entitled "Penicillin for Snowmobile Cranks". It's a live demonstration of a Polaris 900cc motor that has been balanced. I can now do every 900cc Polaris with you just sending your primary clutch and I can do an external balance of the motor for 350.00.
Mr, you need to be careful when you start telling people they don't know how to tru-cranks.....And that you are the higher then thou, And have just figure this all out.
I have news for you, I just watched 2 of your videos and you do not have any idea what your talking about in either of these 2 vidoes.
#1 - you do not know how to, chk or tru a crankshaft ( and I can prove it )
#2 - your TRA video is retarded to say the least. .025 thou run out, ( on the moveable ) Then you added... ( For example ) I understand trust me. 20 plus grams. That clutch is completely junk. In 20 years I have NEVER seen a OEM clutch that needed 23 grams removed in one place.
You need to be careful before you go slamming the OEM's like they pump out nothing but junk. Your runout verses out of balance is stupid to say the least.
Your 1977 balance paper is nice and perfect balance is also nice.... and I am not saying you can't balance things. But your examples and explainations are way out to lunch.
Now don't go getting all pissy, Think long and hard because I promise you this I can explain where your wrong in so many ways and I can do it in a way that the workin man and the engineer can all understand.
I normally don't say much on here anymore, But when someone starts barking they got it all figured out and I see within seconds that they surely do not I have a problem with that.
Dan
Dan, Please be a little more specific here. Looking at this guys credentials being trained to balance jet engine rotating assemblies does seem to suggest that he may know a thing or two even if he is making some claims that seem a little far fetched.
http://www.perksbalance.com/about.html
I do believe that you make the finest Crank for a 900 and do the best job there is balancing a rebuilding a clutch, but it does seem to me like there is some kind of balance problem on these 900 motors. The fact that you added bigger weights to the TM3 crank and it has zero vibration now seems to prove this. (I have a TM3 and can honestly say it is the smoothest snowmobile engine I have ever ridden, even smoother than a dragon 700 or 800.)
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Dan, just read your other post in response to this. You state it is a mass problem vs a Balance problem on the 900's. Can you please explain more for us non engineers? I do not fully understand how adding mass to a crank would make it run with less vibration. This seems to go against everything that is being engineered on engines in the world (unless we are talking Diesels). Adding mass to a an engine crank on a motorcycle(rotating assembly) causes a bike to be less responsive and sluggish in corners.
I'm quite sure my GSXR1000 engine that spins 13000 RPMS has a much lighter crank than a Polaris 900. So by mass problem do you mean it has a lack of mass in the crank counterbalancers to achieve proper balance of the crank? If this is the case than this is still a balance problem and adding external counterbalance weight would seem to be the easiest solution. They do this on car engines.
Please explain so we can all understand better. Thanks
I'm quite sure my GSXR1000 engine that spins 13000 RPMS has a much lighter crank than a Polaris 900. So by mass problem do you mean it has a lack of mass in the crank counterbalancers to achieve proper balance of the crank? If this is the case than this is still a balance problem and adding external counterbalance weight would seem to be the easiest solution. They do this on car engines.
Please explain so we can all understand better. Thanks
Ok Z-man
A short explain.
TO compare a jet engine to a 900 80mm 2 stroke crank is about as strange as it gets.
And there is no doubt anyone that has the balancer he is using can do a find job balaning many items.
In your post you mentioned 1 key word when you refered to the 900....... " Counter balance " What he has done to the 900 is NOT counter anything............counter in balance terms means to create a equal and opossite.... to a problem. He has perfectly round objects on both sides of the crank ( clutch & flywheel ) PLUS He has a Pulley bolted to the clutch to top things off, even more fltwheel effect that will be removed after the fact, do you think thats in the miracle balance job.
What he is demoing here is plain and simple...... Increasing ( Flywheel effect ) ....... And year flywheel effect will do exactly what you said it will cause it to be less responsive and sluggish both. My TM III 900 Crankshaft is about 5 pounds heavier then the OEM crankshaft.......... The advantage to doing it to the crankshaft is that it its closer to the center of the motor verse hanging off the ends...........The weight has the same effect on decreasing ( what Perk ) calls vibration. The 900 has a Zing problem more then a vibrations problem. If the crankshaft is straight and the clutch is nice the 900 doesn't vibrate mush at all. What it does do is ZING right above clutch engagement. and to from not enough flywheel effect........... Not enough mass or weight to pull it thru the long 80mm stroke.
If you owned a V6 Mercury Outboard and sent to the best balance shops in the country or Perk and had it Lightened & balance perfectly for a race motor to their let say 60% spec with all piston assemblies and rods when you get it back and put it together it will shake itself apart.
A Jet engine............. a long continuous shaft right down the middle with very long bearing area to support the rotors. all torque factors dirrectly in line.
Then a 900 Polaris 2 stroke 18 inches long with 4 press point, 2 huge jogs ( or offsets ) Power transfer 90 degrees from crank axis.
To say runout doesn't matter much is child like, 2 stroke crankshafts in watercraft almost never go out of tru........ they are more like a jet engine as far as the load is running straight down the shaft and there is no transfer of power to 90 degrees.
For Gods sake a sled crankshaft goes out of tru when a belt breaks, or the sled lands hard at WOT, and most of the time if the case fit is good the crankshafts go back into tru to some degree never perfect but they get better as you run them.
If you were to balance ( Not add mass ) to a clutch and or flywheel to a crankshaft that was out of tru like to lets say .008 out from a hard landing and then it was all balanced exteranlly and then the sled was driven and the crank runout went down to .003 to next time you drove it the balance job that was just done would be worse for the motor then if it was left alone.
Next in regards to truing a crankshaft on live centers...... This one just about made me fall over.
Ok, #1 the lathe in the picture is an absolute pile of junk, and I would bet 10 to 1 that if you put a certified piece of ground round stock in the chuck and checked it over 10 inchs it would be out .005 minimum. Most week-end garage mechanics think because its a lathe its accurate. Almost never.
Next as to comment on the centers in the crankshaft it was made from..........once the flywheel is pulled and anything contacts the end of the crankshaft integrity of the live center hole is lost forever and should NEVER be used again for centering. ( There is also something called error of location ) once relocated things change.
V Blocks on the 2 center bearings is the only place it should be held.
if you hold it from the ends and the centers happen to be perfect.......
Its like Golf, 2 wrongs can in fact make a right.
If the PTO outter wheel is turned off axis .004 negitive & is still tru to zero, and the MAG outter wheel is turned off axis .004 positive & is still tru to zero. Both center bearings will in fact read zero. ( there are some crankshaft rebuilders that don't know this ) Its called one of 2 things........... thickheaded or inexperience.
And one more thing that really pisses me off, if your holding a crankshaft from live centers and your then checking the crankshaft with a dial indicator on a ( Unloaded bearing ) your check is worthless because there is oil in the bearing and the spring inside the indicator to not strong enough to over come this,
When 27 pound crankshaft is on V blocks its own weight takes most of the error out of the bearings.
That is as basic as I can explain this.
So I say again becareful who you grawl at because they might bite back.
Balance in most cases is a really good thing but it must be kept in context, And not claimed to be the world master crank/motor saver process.
I truely hope I am done with this.
Dan
A short explain.
TO compare a jet engine to a 900 80mm 2 stroke crank is about as strange as it gets.
And there is no doubt anyone that has the balancer he is using can do a find job balaning many items.
In your post you mentioned 1 key word when you refered to the 900....... " Counter balance " What he has done to the 900 is NOT counter anything............counter in balance terms means to create a equal and opossite.... to a problem. He has perfectly round objects on both sides of the crank ( clutch & flywheel ) PLUS He has a Pulley bolted to the clutch to top things off, even more fltwheel effect that will be removed after the fact, do you think thats in the miracle balance job.
What he is demoing here is plain and simple...... Increasing ( Flywheel effect ) ....... And year flywheel effect will do exactly what you said it will cause it to be less responsive and sluggish both. My TM III 900 Crankshaft is about 5 pounds heavier then the OEM crankshaft.......... The advantage to doing it to the crankshaft is that it its closer to the center of the motor verse hanging off the ends...........The weight has the same effect on decreasing ( what Perk ) calls vibration. The 900 has a Zing problem more then a vibrations problem. If the crankshaft is straight and the clutch is nice the 900 doesn't vibrate mush at all. What it does do is ZING right above clutch engagement. and to from not enough flywheel effect........... Not enough mass or weight to pull it thru the long 80mm stroke.
If you owned a V6 Mercury Outboard and sent to the best balance shops in the country or Perk and had it Lightened & balance perfectly for a race motor to their let say 60% spec with all piston assemblies and rods when you get it back and put it together it will shake itself apart.
A Jet engine............. a long continuous shaft right down the middle with very long bearing area to support the rotors. all torque factors dirrectly in line.
Then a 900 Polaris 2 stroke 18 inches long with 4 press point, 2 huge jogs ( or offsets ) Power transfer 90 degrees from crank axis.
To say runout doesn't matter much is child like, 2 stroke crankshafts in watercraft almost never go out of tru........ they are more like a jet engine as far as the load is running straight down the shaft and there is no transfer of power to 90 degrees.
For Gods sake a sled crankshaft goes out of tru when a belt breaks, or the sled lands hard at WOT, and most of the time if the case fit is good the crankshafts go back into tru to some degree never perfect but they get better as you run them.
If you were to balance ( Not add mass ) to a clutch and or flywheel to a crankshaft that was out of tru like to lets say .008 out from a hard landing and then it was all balanced exteranlly and then the sled was driven and the crank runout went down to .003 to next time you drove it the balance job that was just done would be worse for the motor then if it was left alone.
Next in regards to truing a crankshaft on live centers...... This one just about made me fall over.
Ok, #1 the lathe in the picture is an absolute pile of junk, and I would bet 10 to 1 that if you put a certified piece of ground round stock in the chuck and checked it over 10 inchs it would be out .005 minimum. Most week-end garage mechanics think because its a lathe its accurate. Almost never.
Next as to comment on the centers in the crankshaft it was made from..........once the flywheel is pulled and anything contacts the end of the crankshaft integrity of the live center hole is lost forever and should NEVER be used again for centering. ( There is also something called error of location ) once relocated things change.
V Blocks on the 2 center bearings is the only place it should be held.
if you hold it from the ends and the centers happen to be perfect.......
Its like Golf, 2 wrongs can in fact make a right.
If the PTO outter wheel is turned off axis .004 negitive & is still tru to zero, and the MAG outter wheel is turned off axis .004 positive & is still tru to zero. Both center bearings will in fact read zero. ( there are some crankshaft rebuilders that don't know this ) Its called one of 2 things........... thickheaded or inexperience.
And one more thing that really pisses me off, if your holding a crankshaft from live centers and your then checking the crankshaft with a dial indicator on a ( Unloaded bearing ) your check is worthless because there is oil in the bearing and the spring inside the indicator to not strong enough to over come this,
When 27 pound crankshaft is on V blocks its own weight takes most of the error out of the bearings.
That is as basic as I can explain this.
So I say again becareful who you grawl at because they might bite back.
Balance in most cases is a really good thing but it must be kept in context, And not claimed to be the world master crank/motor saver process.
I truely hope I am done with this.
Dan
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dan, sir your amazing and an INCREDIBLE source of knowledge for us all!!
i stand behind you more then you know!!
thanks for taking the time to prevent this guy from scamming the "less fortunate" sled owners out there!!!
your an ASSET
i stand behind you more then you know!!
thanks for taking the time to prevent this guy from scamming the "less fortunate" sled owners out there!!!
your an ASSET
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Thanks for the Explanation Dan. That does make sense completely about the checking crack for true. I never though about the fact that a clutch puller goes into the hole in the end of the crank and causes marring.
It still seams to me that what you are saying is the cranks lack the proper mass and that what you did is add mass to the TM3 to make it run smooth. Is that correct?
If that is correct than shouldn't doing what he is doing have some beneficial effect at reducing vibration just as when running the Primary with the flywheel for the starter seems to?
It still seams to me that what you are saying is the cranks lack the proper mass and that what you did is add mass to the TM3 to make it run smooth. Is that correct?
If that is correct than shouldn't doing what he is doing have some beneficial effect at reducing vibration just as when running the Primary with the flywheel for the starter seems to?
One big problem I see here I think Dan has mentioned is you cannot balance a worn out clutch so without going through the clutch first and making sure it is perfect, how can it even be balanced at all?
You could balance it and recheck it 30 minutes later and it would not show as balanced if it has worn out parts that allow things to shift.
You could balance it and recheck it 30 minutes later and it would not show as balanced if it has worn out parts that allow things to shift.
Great questions Z-man.
Yes, that is exactly correct. As I have said for years..... The single best thing you can do for the least amount of money to a big Polaris Twin is run a Electric Start ring gear.
And yes what he is doing to the 900 in the video will work, Buts its not a balance holy sh!t fix all to the world that was just thought of......Its simlar to what I have been doing to the 900 sense 2007. The difference is its way farther out on the ends of the crank making it in fact feel much heavier.
The reason a small block 800 feels so good is because its a very narrow motor, Long heavy crankshafts create gyroscopic effects that are hard to move off axis at high RPM. This is why triples feel heavier then they are.
And His claim to the 900 being discountinued because of its imbalance is incorrect.
The 900 Crankshaft lacks mass........ Its simply to lite.
You want a example you all can wrap your head around ?
Take the clutch off your sled..........Sit on it, start it up and rev it up to 5000 rpms 4 or 5 times quickly and tell me how pleasant this feels.
The feeling will not be imbalance that he preaches..........Its simply a lack of mass. ( Or flywheel effect ). This is not front page news this dude is painting a pile of turds a different color and calling them something different.
Dan
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Bingo, You would be 100% correct in the example of the used TRA clutch he shows.
Its a woren out pile of junk and the video is worthless to say the least.
And another thing he claims, Balancing a drive clutch with the clutch weights installed is correct...........Its a bad idea and is not good for the customer.
The reason its a bad idea.... Almost every set of 3 mass production clutch weights are not exactly the same, you can see differences of up to a gram off maybe a little more but its very rare.
Once a clutch leaves the shop that has been balanced............Most customers are going to change weights at some time many within the same year that go outwest.
If you balance a drive clutch with a set of production weights that has 1 weight that is 1 gram heavier then the other 2 and that customer changes weights and lets say this new set that has a weight that is 1 gram lighter then he other 2 and it lands in the spot where the heavier one was ......
That is the huge swing I want to prevent.
You would have to be a fool to think the pulic as a whole is going to balance their clutch weights everytime.......Most would not have the tools or know how to balance them.........Not because they are dumb or anything, But because they do not know where the weight is to heavy.
I.E. The tip, Or the heel.
Dan
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TRA Clutch was not Junk
IndyDan
I'd like to address one of your claims or assertions (see below)
#2 - your TRA video is retarded to say the least. .025 thou run out, ( on the moveable ) Then you added... ( For example ) I understand trust me. 20 plus grams. That clutch is completely junk. In 20 years I have NEVER seen a OEM clutch that needed 23 grams removed in one place.
The clutch was not junk, it had been just cleaned, bushings replaced (even a little tight for my liking), clutch kit freshened with new springs, slide channels/towers were polished. It had not recieved any damage, that I know of, and was in Good working condition.
I would also like to say that comparing the castings of these clutches over the years, they have gotten alot worse. Build it quick and cheap seems to override quality and longevity.
I can't speak to the Polaris crank issues and blowing belts, but Skidoo has replaced my engine a couple of times, all relating to bearing issues. Now for about the cost of Boysenn Rage Cages and Wings (That I saw no differance or increase with) I can try to keep an engine for more than 3k miles, not too bad....
To me as an engineer, who deals with suppliers of Jet Engine parts and have spoken to bigger brains than mine, it makes sense to remove as much vibration as possible and reducing unbalance is critical.
I'd gladdly post pics of the clutch for examination, or you check out the thread over on DooTalk.com in MachZ Section.
Later
GutZ
IndyDan
I'd like to address one of your claims or assertions (see below)
#2 - your TRA video is retarded to say the least. .025 thou run out, ( on the moveable ) Then you added... ( For example ) I understand trust me. 20 plus grams. That clutch is completely junk. In 20 years I have NEVER seen a OEM clutch that needed 23 grams removed in one place.
The clutch was not junk, it had been just cleaned, bushings replaced (even a little tight for my liking), clutch kit freshened with new springs, slide channels/towers were polished. It had not recieved any damage, that I know of, and was in Good working condition.
I would also like to say that comparing the castings of these clutches over the years, they have gotten alot worse. Build it quick and cheap seems to override quality and longevity.
I can't speak to the Polaris crank issues and blowing belts, but Skidoo has replaced my engine a couple of times, all relating to bearing issues. Now for about the cost of Boysenn Rage Cages and Wings (That I saw no differance or increase with) I can try to keep an engine for more than 3k miles, not too bad....
To me as an engineer, who deals with suppliers of Jet Engine parts and have spoken to bigger brains than mine, it makes sense to remove as much vibration as possible and reducing unbalance is critical.
I'd gladdly post pics of the clutch for examination, or you check out the thread over on DooTalk.com in MachZ Section.
Later
GutZ
Hello GutZ. Great questions.
Thew clutch I saw in the video sure doesn't look clean it looks like it just came off a sled with 4000 miles on it.......BUT if in fact it was just rebuilt, and the shop that was now going to balance it saw it had .025 thou runout he should have called and told the customer its junk.
I am 99.9% sure there are no machined in Ski Doos machine shop that have enough wear to produce anything that is in fact .025 thou out of center.
For Gods sakes a $500.00...... 20 year old bridgeport with 50,000 hours on it could get the bore center with in .005.
a 12 pouind clutch that has .025 runout should not be balanced it should be throwen away.
That is why I have problems with this guys claims. The things that are said to be done are stupid.
In 25 years I have never seen a clutch like this other then a few that had been hit in the drive clutch by another sled or impacted a stump. ( the center post was bent )
Dan
Displacement not Hubcentric Distortion
Dan
Sorry it's taken so long to respond, we just got 24 inches of Wet Snow! But we still had leaves on the trees, so they all came down and we have no power or heat or cable....
I believe that the ".025 thou runout" in this case is not an axial displacement or machining distortion, but a displacement caused by the unbalanced force moving the machines/balancing equipment by that much as the clutch spins. Once balanced the clutch ran smooth, to me, in the video. No amount of balancing can remove "Mechanical" runout. I believe just this balancing will save me huge Dollars down the road.
Maybe Joe can elaberate more.
Thanks
GutZ
Dan
Sorry it's taken so long to respond, we just got 24 inches of Wet Snow! But we still had leaves on the trees, so they all came down and we have no power or heat or cable....
I believe that the ".025 thou runout" in this case is not an axial displacement or machining distortion, but a displacement caused by the unbalanced force moving the machines/balancing equipment by that much as the clutch spins. Once balanced the clutch ran smooth, to me, in the video. No amount of balancing can remove "Mechanical" runout. I believe just this balancing will save me huge Dollars down the road.
Maybe Joe can elaberate more.
Thanks
GutZ
No-problem Gutz:
Run out should not be measured while the clutch is on a floating live center. of course runout & balance are 2 different things.
The fact that he put 23 to 28 grams of added weight in one spot tells me something is really wrong with the TRA example in the video.
Actual runout will throw all balancing efferts out the window. runout must be corrected to factory specs or better before balancing is done.
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