Crankshaft main bearing problem

[jumjum01]

Help... I have a problem fitting my new Gen2 crank into my gen1 engine case. The oil clearence is too small on one of the five main bearings. I have selected the thinnest (green) bearing for this. When thightening crank bolts to torque spec. 32NM the crank will turn, but when putting a piece of 0.01mm steel (min. oil clearence) on top the crank will lock up.

 

[202mphbusa]

Help... I have a problem fitting my new Gen2 crank into my gen1 engine case. The oil clearence is too small on one of the five main bearings. I have selected the thinnest (green) bearing for this. When thightening crank bolts to torque spec. 32NM the crank will turn, but when putting a piece of 0.01mm steel (min. oil clearence) on top the crank will lock up.

EEEIIIICK

Why would you put a piece of shim stock on your crank?
think about it, if you take away ALL the clearance how CAN it turn?

 

[jtwrace]

Yikes!

Do NOT do that...if you want to check installed clearance use the Plastigauge as that's what they're designed for.

 

[202mphbusa]

BTW .01MM is 0.000393701
In machinist speak almost "four tenths"
did you mean 0.1mm? which would be almost "four Thousands"
Which would be towards the high limit wouldn't it?

I have never had great luck with plastic gauge
Always seem to rotate the rod/crank and get poopy results

 

[jtwrace]

I have never had great luck with plastic gauge Always seem to rotate the rod/crank and get poopy results

You don't rotate with a Plastigauge. Read the directions.

EDIT: I read it again..so you're saying you accidently rotate with it. Hmmm never had that happen.

 

[202mphbusa]

You don't rotate with a Plastigauge. Read the directions.

EDIT: I read it again..so you're saying you accidently rotate with it. Hmmm never had that happen.

Really? never had it rotate??

Huh I will have to redo it 3-4 times to get usable results

 

[jtwrace]

Really? never had it rotate??

Huh I will have to redo it 3-4 times to get usable results

I've never done a busa but I've done too many others to count and haven't had an issue.

 

[202mphbusa]

I've never done a busa but I've done too many others to count and haven't had an issue.

Only motor I rebuild on a regular basis in YEARS is my Busa
rods.....too easy while torqing to move
Mains.....I double check my main bore to what it has been since line honing.....,measure crank
Rods/throws I measure in MULTIPLE places on both and do the math

 

[jumjum01]

I use shim stock, because i was told not to trust plastigauge. Oil clearence per manual should be between 0.010 to 0.028mm, service limit is 0.080mm. So if I put 0.01mm shim and crank can rotate I know that clearence is bigger than 0.010mm and I wont be too tight.

 

[sixpack577]

Install the journals and measure with bore gages and a micrometer.
(not a Busa block pictured, obviously).

 

[jumjum01]

I was able to hone the case/ bearing seat to get the correct oil clearence. Bike is assembled and ready to fire up. Any advise for break in/ running procedure??

 

[Redcurbjumper]

Install the journals and measure with bore gages and a micrometer.
(not a Busa block pictured, obviously).

View attachment 1651107
make sure you know the proper way to use these snap gauges.... I thought I did for 30 years and was shown the error of my ways by a 80 year old machinist recently. Man did I feel stupid. You don’t try to tighten the set screw while trying to perfectly align the plungers vertically in the bore. Right way= put the gauge in the bore at a slight angle with a tiny bit of friction on the plungers. Then rock it through the vertical position and when it comes loose it has “taken” the max diameter measurement. lightly measure it with your micromete now. Or buy a dial bore gauge and make it easy on yourself

 

[Redcurbjumper]

I was able to hone the case/ bearing seat to get the correct oil clearence. Bike is assembled and ready to fire up. Any advise for break in/ running procedure??

Prelube the engine using a garden sprayer filled with oil and hook it to an oil galley to build oil pressure and purge air out of the oil system.

 

[202mphbusa]

Prelube the engine using a garden sprayer filled with oil and hook it to an oil galley to build oil pressure and purge air out of the oil system.

I made a tool to spin the oil Pump without the gear on it
only issue is If I don't put my finger over the clutch pushrod hole I get soaked

 

[sixpack577]

Install the journals and measure with bore gages and a micrometer.
(not a Busa block pictured, obviously).

View attachment 1651107

View attachment 1651108

View attachment 1651109

Fyi
That bore gage is tight in the bearing, to fully show it for the picture.
In hindsight, that was a bad idea, as it can be percieved as the correct way to take a measurement...which it is not.
The gage is snugged in place so it will sit there for the picture, but that is too tight for an accurate measurement.
I see people too often cranking on micrometers(the wheel too, not the clutch, if it has one)
@Redcurbjumper pointed out the correct way to read these earlier today, so I wanted to clear things up with the picture too.