very sorry for you
it look's more like vibrations crack , rather than effort crack , dont you think ?
.
The technical adventures of Dr_C
- Thread starter Dr_C
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very sorry for you
it look's more like vibrations crack , rather than effort crack , dont you think ?
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Sad state of affairs indeed.
Tons of effort for such a catastrophic fail, big HP is tough on parts!
Main bearing short comings were why I switched to the 70 degree motor, bigger main seem to handle the abuse better. Before my Berg I had an RFS motor that I way built for HP and had an appetite for mains. Never blew one like that but they would be noise and junk and would require frequent changes.
Tons of effort for such a catastrophic fail, big HP is tough on parts!
Main bearing short comings were why I switched to the 70 degree motor, bigger main seem to handle the abuse better. Before my Berg I had an RFS motor that I way built for HP and had an appetite for mains. Never blew one like that but they would be noise and junk and would require frequent changes.
Joined Oct 2003
955 Posts | 1K+
Sweden
Been there. The shroud of the inner ring got torn off (angular problem due to crank spread) and the debris destroyed both liner and piston before I noticed the damage. I figured that ball bearings would give me a heads up and not throw debris around. I was wrong about that. For this season it will be ball bearings and 5-6 hours replacement interval.
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
Joined Nov 2001
17K Posts | 774+
Ely, England
Mats
are you using a ring on the crank to pull the crank to the left? you know, the ring is in the left cover and the nut tightens the gear onto the ring which is butted against the main bearing?
I don't think the balls can take it full stop. I think you're waisting your time persevering with them, they can't give you any axial float and it is clear the rollers need 0.6mm anyway. so the balls are wandering around in their races.
the balls can't give that. the trouble with the rollers is that their maximum rev ceiling is below your redline.
Taffy
are you using a ring on the crank to pull the crank to the left? you know, the ring is in the left cover and the nut tightens the gear onto the ring which is butted against the main bearing?
I don't think the balls can take it full stop. I think you're waisting your time persevering with them, they can't give you any axial float and it is clear the rollers need 0.6mm anyway. so the balls are wandering around in their races.
the balls can't give that. the trouble with the rollers is that their maximum rev ceiling is below your redline.
Taffy
Joined Oct 2003
955 Posts | 1K+
Sweden
No, not that much. Before RST* I used ball bearings with some 0,4-0,6 mm axial play, without any problems. I also tried rollers with 0,8 mm axial play, but as I mentioned the inner ring shroud was knocked off, causing a lot of damages, also to the counter balancer. My cranks didn't have the better support for the inner ring as they had from ... 2005 (?). Whats your track record with that large axial play? Can the crank use that play?
* RST - Ridiculous State of Tuning
No, I do not fixate the crank around the left bearing. My english skills are not very good. What do you mean with: "I don't think the balls can take it full stop"?
No, I cannot go on with ball bearings and that is not my intention either. But they will have to do for this season. Then we will see if I will continue this development, or feed the pigeons. A solid crank, angular contact ball bearings (Ducati-style with prepress), tall 2-piece conrod, 6-speed gear box, billet cases and a dry clutch makes my mouth water...
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
RST !
ive used 1mm axial play with no problems on the 105mm piston, generally max rpm is 9k but according to my data logger ive done 10k a few times LOL, crank is heavier than stock, roller bearings showed less wear than with 0.8mm axial play
I would think that 1.5mm axial play may not be used but that is just a 50/50 guess, if there was time to experiment and i had an RST engine I would try no CB replaced with a really nice supporting spacer for a 20mm wide 2206 NJ roller, and a NTN NJ206 roller on the other side and 1.2mm axial play minimum.
currently in the 700 I run a 22206 spherical roller on the drive side and an NTN nj206 on the ign side with 0.8mm float .. looked all good at 25 hrs hard labour (i broke another gear LOL)
what were contimans conclusions with his spherical rollers and 710 cc RST on an 82mm crank ? i think his tiny pin welds cracked IIRC
In my 628 i run 22206 spherical rollers with 0.1mm axial play, pin welded really really solid .. big er70s2 fillet all the way around, crank is very light and it sees 10K regularly .. all ok @55 hrs but ive not looked inside
there is absolutely no point in a husaberg in locking the crank to one side with a ball on the drive IMHO, there just isn't enough room axially to warrant locking it, honda does that with a ball one side and a roller the other but the purpose of locking it to one side is to stop the crank flapping around axially as they are set with nearly 3mm "axial play" (should you remove the retaining collar and move the crank side to side to measure it) if you could achieve the 2-3mm axial gap that honda does it would be a nice finishing touch but at floats up to 1- 1.5mm i think it is not needed.
the engine you describe is a beautiful concept Dr_C! i have dreamed up many combinations of parts to acheive the same but with ony a MST looking forward to pictures of the build ... not pictures of pigeons
ive used 1mm axial play with no problems on the 105mm piston, generally max rpm is 9k but according to my data logger ive done 10k a few times LOL, crank is heavier than stock, roller bearings showed less wear than with 0.8mm axial play
I would think that 1.5mm axial play may not be used but that is just a 50/50 guess, if there was time to experiment and i had an RST engine I would try no CB replaced with a really nice supporting spacer for a 20mm wide 2206 NJ roller, and a NTN NJ206 roller on the other side and 1.2mm axial play minimum.
currently in the 700 I run a 22206 spherical roller on the drive side and an NTN nj206 on the ign side with 0.8mm float .. looked all good at 25 hrs hard labour (i broke another gear LOL)
what were contimans conclusions with his spherical rollers and 710 cc RST on an 82mm crank ? i think his tiny pin welds cracked IIRC
In my 628 i run 22206 spherical rollers with 0.1mm axial play, pin welded really really solid .. big er70s2 fillet all the way around, crank is very light and it sees 10K regularly .. all ok @55 hrs but ive not looked inside
there is absolutely no point in a husaberg in locking the crank to one side with a ball on the drive IMHO, there just isn't enough room axially to warrant locking it, honda does that with a ball one side and a roller the other but the purpose of locking it to one side is to stop the crank flapping around axially as they are set with nearly 3mm "axial play" (should you remove the retaining collar and move the crank side to side to measure it) if you could achieve the 2-3mm axial gap that honda does it would be a nice finishing touch but at floats up to 1- 1.5mm i think it is not needed.
the engine you describe is a beautiful concept Dr_C! i have dreamed up many combinations of parts to acheive the same but with ony a MST
looking forward to pictures of the build ... not pictures of pigeons
Joined Nov 2001
17K Posts | 774+
Ely, England
Mats
the idea of it is that you must use a ball and roller combo. by pulling the crank hard left the ball race sits true and square all the time while the right hand side takes all the expansion and contraction through a roller that has lots of axial space.
I don't think it's ideal but it might be a fix that is better than double ball to get you to the end of the year.
the Ballards in the UK have opened out the left main and have no oil seal there. they quite literally have two rows of rollers on the left now.
I don't think the spherical roller supports and guides the crank? whether it should or not depends on your opinion? a wooden lighthouse that bends with the wind or a super strong one made of bricks and mortar?
I doubt anyone is pushing these bikes the way you are, no two applications are the same. intense sustained maximum revs pulling a lightweight with little tyre slippage is not the same as bloke in a field. even ScX is just short blips and bursts with the temperature remaining far lower.
regards
Taffy
the idea of it is that you must use a ball and roller combo. by pulling the crank hard left the ball race sits true and square all the time while the right hand side takes all the expansion and contraction through a roller that has lots of axial space.
I don't think it's ideal but it might be a fix that is better than double ball to get you to the end of the year.
the Ballards in the UK have opened out the left main and have no oil seal there. they quite literally have two rows of rollers on the left now.
I don't think the spherical roller supports and guides the crank? whether it should or not depends on your opinion? a wooden lighthouse that bends with the wind or a super strong one made of bricks and mortar?
I doubt anyone is pushing these bikes the way you are, no two applications are the same. intense sustained maximum revs pulling a lightweight with little tyre slippage is not the same as bloke in a field. even ScX is just short blips and bursts with the temperature remaining far lower.
regards
Taffy
Joined Oct 2003
955 Posts | 1K+
Sweden
There is no time to experiment, I'm afraid... Let's say I would go for this configuration, do I HAVE TO rebalance the crank? Both my piston and rod are heavier than stock and I'm using the 80mm crank.
Regarding the NJ206, I have bad dreams from those inner ring shrouds being knocked off (0,8mm play), causing all kinds of Mayhem... :unsure:
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
FWIW im running a bolted paddle tyre and ripping gears clean in half .. not as high rpms but no one else can do that except me LOL
ive only tried balance factors of 0.75, 0.58, 0.54 (approx) and 0.625
definitely around 0.62 feels the best for my chassis/bars etc
I would try it without re balancing the crank first to see if its bareable
yes you would have to add quite a lot of weight in your RST to the crank in order to bring the balance factor up to 0.6, but perhaps 0.4 would be nice as well
the amount of material you could remove from near the pin without having bad dreams with the rst would be very minimal I guess.
you could keep the cb and still run 20mm wide bearing albeit with less ideal axial support for the nj roller lips
spanner bored the drive side main tunnel deeper and added a retaining plate on the outside
http://husaberg.org/mechanical/17170-definative-main-bearing-thread-8.html
ive only tried balance factors of 0.75, 0.58, 0.54 (approx) and 0.625
definitely around 0.62 feels the best for my chassis/bars etc
I would try it without re balancing the crank first to see if its bareable
yes you would have to add quite a lot of weight in your RST to the crank in order to bring the balance factor up to 0.6, but perhaps 0.4 would be nice as well
the amount of material you could remove from near the pin without having bad dreams with the rst would be very minimal I guess.
you could keep the cb and still run 20mm wide bearing albeit with less ideal axial support for the nj roller lips
spanner bored the drive side main tunnel deeper and added a retaining plate on the outside
http://husaberg.org/mechanical/17170-definative-main-bearing-thread-8.html
Joined Sep 2007
782 Posts | 291+
???
Roller bearings do not like the crankshaft flexing.
Lighter reciprocating mass helps reduce flex.
Well welded crank pin helps reduce the flex.
Lighter crankshaft revolving mass reduces stress from the transmission.
The load carrying ability of a roller is far more than a ball bearing.
The rpm capability of a roller is less than a ball race, but it would
depend on the time spent over that limit as to weather
it would cause a problem or not.
C3 or better C4, NTN bearing will help cope with the flex. I have a SKF 2206 C3 on the LH side ( because I could not get an NTN 2206 C3/C4 ) and a
NTN NJ206 C3 on the RH side.
Polyamide? cage causes less damage if bearing fails.
The axial play 'seems' to be related to the amount of flex.
The counter rotating balancer is to balance the reciprocating mass.
My 675`s reciprocating mass was slightly lighter than Std 628 so I made no adjustment and feels just the same as stock as far as vibration is concerned.
Might try no counterbalancer on next motor, with a revised balance factor, But not convinced it will be good for the street or reliability.
Detonation may cause bearing failure also.
Overreving on these motors should be avoided IMO.
A good experiment would be to see how much lap time changes
by dropping the rev limit by 1000 rpm. 1000 rpm less would take a huge lode
off these cranks.
Just some rambling to add to the conversation
Lighter reciprocating mass helps reduce flex.
Well welded crank pin helps reduce the flex.
Lighter crankshaft revolving mass reduces stress from the transmission.
The load carrying ability of a roller is far more than a ball bearing.
The rpm capability of a roller is less than a ball race, but it would
depend on the time spent over that limit as to weather
it would cause a problem or not.
C3 or better C4, NTN bearing will help cope with the flex. I have a SKF 2206 C3 on the LH side ( because I could not get an NTN 2206 C3/C4 ) and a
NTN NJ206 C3 on the RH side.
Polyamide? cage causes less damage if bearing fails.
The axial play 'seems' to be related to the amount of flex.
The counter rotating balancer is to balance the reciprocating mass.
My 675`s reciprocating mass was slightly lighter than Std 628 so I made no adjustment and feels just the same as stock as far as vibration is concerned.
Might try no counterbalancer on next motor, with a revised balance factor, But not convinced it will be good for the street or reliability.
Detonation may cause bearing failure also.
Overreving on these motors should be avoided IMO.
A good experiment would be to see how much lap time changes
by dropping the rev limit by 1000 rpm. 1000 rpm less would take a huge lode
off these cranks.
Just some rambling to add to the conversation
Last edited:
Joined Nov 2001
17K Posts | 774+
Ely, England
I convert everything to roller on the 650s so I throw these rings away. I'll send you one straight away and then at least you have it infront of you as an option.
they fit a larger oil seal because the seal is on the ring NOT on the crank anymore.
it doesn't affect the balance as it is a ring.
I really don't know that this is the answer but if the balls are toast that quickly, i reckon it has a chance. either way, with the ring and seal sitting there you can make your own decision.
Taffy
I don't understand much what you all are talking about, but I enjoy looking at the pics very much. Also I enjoy this fancy engineers language that you use. Don't want to interfere too much, as I'm not worthy but I have a couple questions;
Are you all formally educated in engineering? To what degree, you can't be just mechanics, there has to be at least somebody here with a professors degree...
Mats, have you ever received a Nobels prize for your accomplishments in engineering? Have you worked for Husaberg or any other major (minor) motorcycle manufacturer? Would you donate a piece of your brain to me?
(To all) How come you choose Husaberg engines for your projects/experiments? Do you consider them superior, a good basis, easy to work on, inexpensive?
And an observation;
Taffy, seems like you can write and post in English so everybody understands and you can address people with due respect. Why don't you do it more often even with people who are not as educated/knowledgeable as these guys here? Please try....
Regards!
M.
Are you all formally educated in engineering? To what degree, you can't be just mechanics, there has to be at least somebody here with a professors degree...
Mats, have you ever received a Nobels prize for your accomplishments in engineering? Have you worked for Husaberg or any other major (minor) motorcycle manufacturer? Would you donate a piece of your brain to me?
(To all) How come you choose Husaberg engines for your projects/experiments? Do you consider them superior, a good basis, easy to work on, inexpensive?
And an observation;
Taffy, seems like you can write and post in English so everybody understands and you can address people with due respect. Why don't you do it more often even with people who are not as educated/knowledgeable as these guys here? Please try....
Regards!
M.
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
the other option i mentioned a while back is to run preloaded ducati style angular contact balls as has been done in ktm rfs engines up to 613cc but IMHO the berg cases are not strong enough axially especially the drive side and even more so in for matts RST beast
there is room for 2 of 4 - 5 mm thick bisaloy plates on the outside of the cases (eg where spanner has the alumnium plate added)
my plan was to run the plates forward to be clamped together by the 2 engine mount bolts at the front and put a long bolt (or 2) through the engine to hold the plates together at the rear near where the long m6 case bolt goes
my dear M! i wager that the only difference between you and "us" is mechanical OCD and time spent in the shed. I chose husaberg because of the power to weight of the engine being very nice
there is room for 2 of 4 - 5 mm thick bisaloy plates on the outside of the cases (eg where spanner has the alumnium plate added)
my plan was to run the plates forward to be clamped together by the 2 engine mount bolts at the front and put a long bolt (or 2) through the engine to hold the plates together at the rear near where the long m6 case bolt goes
my dear M! i wager that the only difference between you and "us" is mechanical OCD and time spent in the shed. I chose husaberg because of the power to weight of the engine being very nice
Last edited:
Joined Sep 2007
782 Posts | 291+
???
Everyone who was doing them this way has stopped. A buddy who is a builder on KTM talk who did about 10 angular conversions said all but one came back to him failed so that does not work I can guarantee. Not one of my motors but he ate a lot of warranty work fixing things. Cases broke, etc.
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
yes Chris i know the story very well
I still think it would work if you were to make the steel plates to hold the cases together with big bolts. Ducatis work very well with their ACs
the real solution obviously is bigger bearing and a lighter more rigid crank which leads to a new engine design ..something im very keen to do myself as well
I still think it would work if you were to make the steel plates to hold the cases together with big bolts. Ducatis work very well with their ACs
the real solution obviously is bigger bearing and a lighter more rigid crank which leads to a new engine design ..something im very keen to do myself as well
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