Definative main bearing thread

[WArdogG]

The code on the ProX bearing is ECS46, it is an NTN bearing with a polyamide cage.

Regarding the 450 crank, the interference fit between the web and the pin wasn't a lot, so I believe that this was causing excessive spreading and resulting in the mains not lasting more than about 20hrs. So if i weld the pin I'm hoping to get the 'normal' amount of spread, so the bearing can maybe go a little bit longer

For interests sake, do you know what the ideal interference fit between web and pin should be more or less?

I have my cranks trued to 0.02mm or as close as we can get it, but when re-measuring the 450 crank after removing it was close to 0.3mm, so you could actually see the thing wobbling at the ends when it was on the V-block. And when we pressed it apart it didn't take as much force to separate the webs, we measured the pin and the bore at that stage though I didn't write it down, and the guy said to me the interference should be more.

I think it may be a good thing to also check the pin to web interference, especially when a crank has been pressed a couple of times.

 

[WArdogG]

The code on the ProX bearing is ECS46, it is an NTN bearing with a polyamide cage.

Regarding the 450 crank, the interference fit between the web and the pin wasn't a lot, so I believe that this was causing excessive spreading and resulting in the mains not lasting more than about 20hrs. So if i weld the pin I'm hoping to get the 'normal' amount of spread, so the bearing can maybe go a little bit longer

For interests sake, do you know what the ideal interference fit between web and pin should be more or less?

I have my cranks trued to 0.02mm or as close as we can get it, but when re-measuring the 450 crank after removing it was close to 0.3mm, so you could actually see the thing wobbling at the ends when it was on the V-block. And when we pressed it apart it didn't take as much force to separate the webs, we measured the pin and the bore at that stage though I didn't write it down, and the guy said to me the interference should be more.

I think it may be a good thing to also check the pin to web interference, especially when a crank has been pressed a couple of times.

 

[Dr_C]

Okay thank you. Do you honing out both bearings or the only one on the ignition side? What axial clearence for the crank are you using?

Thank you very much!

Best Reguards Max

Yes, I hone out both bearings. Axial play is 0,6 mm. With my new counter balancer also the axial position of the crank becomes important to control.

Skickat från min SM-A520F via Tapatalk

 

[bushmechanic]

Hi wardog

So not the extra hard ntn with modified roller geometry for high misaligned loads

Interference fit on the pins usually measures 3 thou on the bergs. It should be 4 to 5

Compared to jap cranks with similar big end diameter the bergs are very loose

Welding observations here http://husaberg.org/mechanical/11632-crank-welding-rebuild-balance.html

 

[WArdogG]

Welding observations here http://husaberg.org/mechanical/11632-crank-welding-rebuild-balance.html

Basically everything you say here is I think what I have encountered with this 450 crank. Oval bores in the webs and so on. Thanks, that is a very informative post.

 

[Bergfest]

Hi @,
checking the axial crank play I found only 0.25mm pushing/pulling fly wheel by hand!
Bike is a FC650 Year 2007.

More facts
- Engine is running 75 hours since rebuild by non Husaberg specialist with original bearings.
- Very few metal flakes at magnetic plug.
- 5 track days were very hot 32 to 35 degrees celsius last 2 years

What is your advice with crank play like this when engine is running fine?

 

[Spectre889]

Hey i have a 2000 FE 501, i have to replace the engine bearings. can you list all raccomend bearings?

 

[MIKI]

I would like to thank you in advance for the large amount of inspiration, knowledge and ideas.
HusaberG has been my hobby for more than 15 years.
So far I have used it a lot and improved a bit. Now I want to embark on major engine modifications for reliability and performance.

I'm just an observer and I'm still learning. I have long been dealing with problems with the low life of the main crankshaft bearings. I solved the repairs with the most accurate alignment of the flywheels, greater axial play and quality bearings. Nevertheless, there is an unplanned stop.
I dealt with "an unknown force that bends a pin and destroys flywheel bearings. I will add my theory of a design flaw in the production of the crankshaft.
In my opinion, the flywheel itself is poorly balanced radially. The very force of the eccentric weight deforms the pin and bearings. I attach a picture for reflection and discussion.

Red is the weight that acts on the expansion of the flywheel plates - it is off the axis of radial balance.
Green is a theoretical weight that eliminates the defect - it moves the center of gravity closer to the bearing.
Then the distance of the bearings from the plate also decides, see photo of 2 different flywheels with different deflection according to the location of the bearings. The flywheels on the balancer are more bent than on the ignition.

 

[Dr_C]

Hi guys!
I'm currently refurbishing an 2002 650, close to stock. I'll try the single row spherical roller bearings from SKF, 20206 (30x62x16) on both sides. Have anyone tried them out?

Thanks!

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[Jonska]

Hi!

I have lightened 80mm crank and CB removed. I had about 0.15mm end float without shims before CB removal. Now I use 16mm & 20mm rollers, with shallower cb spacer to get more clearance.

Does it matter which side i put shims? Does it matter if crank gets little "off center" if it's free to spin? If I put shims to flywheel side as manual says, then crank obviously is more at the clutch side.

 

[Taffy]

put it together without the piston. go to TDC and measure the distance from the rod eye to the liner and to the left and to the right. they tens to need packing to the right of the cases.

Taffy