The fms had exactly what jlinney is talking about going on

The crank was quite a bit longer than the bearing spacing was , by about .6mm fareal
Thats called the race Elvind , if your front bearing looks like it moves too much to ya then change it , its probly ok though, these engines do have some nominal clearances built in . If the front bearing is all dirty and nasty its probly time for a new one anyway

Great post jlinney

+1

If you are really anal, you can shim the crank to rear bearing. This would put some of the load back onto the rear bearing, as well. But it's a bit of a PITA to get it right, and not many make proper sized shims.

The inner race of the front bearing should be pinched between the but end of the crank and the backside of the collet...If this is seated correctly and there is still too much in/out thrust it means the front bearing is junk...........the rear bearing should not have any trust load placed upon it, that front bearings inner race is what the crank is bottomed to, not the rear bearing.....

Why would a man. make a crankcase/crank setup to put the tension of the load on the front bearing ?

If all is built properly and seated properly the load will and should be shared between both bearings which is why the cc code bearings that novarossi boasts have a 6 x 6.3mm rear bearing now

do a dye contact test and see for yourself..you just might learn something ! the crank will bottom out on the front bearing before any thrust is put onto the rear bearing....on some engines the front bottoms out before the crank even makes contact to the rear........

Excuse me i was mistaken nova narrowed the outer race to 5.85 and left inner race at 5.98 just creating a small stepped race like the front 6 x 6.3

Tap the crank in to seat against rear bearing

Maybe thats why my front bearings last so long ?

ok i just measured 6 different novarossi made blocks with bearings and cranks very thoroughly , there were some blocks that the distance from bearings inner races was different than the rest but on average it was 29.55mm most of the cranks measuring from each of the same contact areas was average 29.60-63mm of course a difference of .05-.08mm , after tappeing the crank in to seat up against both bearings at the same time which in turn pushed front bearing out ever so slight everytime the gap/difference in measurement was taken up and no more movement

Any of you adds or removes shims according to the track you are running? More shims if you are racing on a real high speed track and vise versa? How about cold and really hot weather?

Thanks gentlemen

use some machinist dye, it will show you if your making contact or not...which it is not....If it was like you said and each bearing had opposing thrust then we would never see a bad front bearing allow the crank walk back and forth...the opposing thrust on the bearings would never allow that movement..... The crank just hovers right at the rear bearing, usually not making full contact and most definitely not applying any thrust........As I say for something like this you need to use a contact dye........using a vernier caliper to measure this is not adequate as a caliper is not accurate enough...

And dude do you really think I am silly enough to not know to push a crank into a engine ? LOL......:rolleyes::rolleyes:

Did i say Neal , youre a dumbass for not seating the crank? Really ?

I think you need to relax a lil

Tell me why it doesnt make more sense to have the crank "riding" up against the rear bearing as opposed to the smaller front bearing and less able to take the same force as the rear larger bearing

LOL there is no drama here...I already know I am right on this one...... I had a batch of engines come here that were machined incorrectly and when you tightened the flywheel it actually did put opposing thrust on the bearings.... And lets just say the results were not good at all...The last thing we want is thrust load put onto the engine bearings,,And yes the front bearing does hold the crank in place, and a bad front bearing will allow the crank walk in and out........

It very well may be possible that once the engine is up to operating temperature the crank contacts the bearing...as everything expands differently...the aluminum case will expand much more then will the steel crank.....So the gap I speak of may just be clearance for heat expansion...I Am not sure if the clearance is still there when the engine is running as it is impossible to test........As I say I went thru all this a few years back when I got a batch of engines that were machined incorrectly ...When you mounted the flywheel there was thrust put onto the bearings and the engines behaved very badly because of it... Some would run, but get tight when hot, others would just lock up when you mounted the flywheel........

i think you are misunderstanding what i am saying , oh well

you are right , you wouldnt want "active" thrust on bearings not meant to take axial thrust .

which is a great reason to switch to novarossi engines so as to cut down on the improperly machined , misaligned engines from some other lesser manufacturers , smart decision on your part for sure

i made that decision in 2002 ;)

in my best austin powers voice "oh misbehave!!"

i hate when the engines are misbehavin :lol: time for them to get beat :cool:

hmm..I wonder what company had bad machining that Neal speaks of. I think It could be the motor I ran last year the would be great down to the bottom of one tank and after a pit stop about 4 laps in would start flaming or running erratic. Or once it gets over 220 the case over expands and starts running erratic. Oh and my favorite is when the idle stop screw breaks for no reason. I wouldn't give that motor to the points leader at my local track because its a turd! I saw the light half way into the season last year and started looking for my newest Novarossi.

VIVA LA NOVAROSSI!

Break it up!