2F Main Bearing clearance (1 Viewer)

[DRT1]

Between .051 and .076 main bearing clearance. Continue build or tighten it up a bit? Manual says .10mm limit! Crankshaft was milled 0.020 over so I purchased 0.020 over bearing. Looking like it may have already been milled .020 and another .020 was taken off. Would a .040 bearing get me where I need to be?

 

[charliemeyer007]

Um it might just be the pic's on my box but I can't see what you are measuring. Usually they measure what is there to start with and undersize it to the next available size that cleans them all up. O.051" is 1.295mm

 

[pb4ugo]

Um it might just be the pic's on my box but I can't see what you are measuring. Usually they measure what is there to start with and undersize it to the next available size that cleans them all up. O.051" is 1.295mm

His measurement are in mm. 0.051mm = .002" 0.076mm=.0029"

To me, the plastigage looks like 0.076mm or 0.0029". which in my opinion seems loose. What's the manuals spec.

 

[DRT1]

His measurement are in mm. 0.051mm = .002" 0.076mm=.0029"

To me, the plastigage looks like 0.076mm or 0.0029". which in my opinion seems loose. What's the manuals spec.

STD. 0.020-0.044mm
Limit 0.10mm
It is loose. To loose? I may have some 0.020mm main bearings to sell.

 

[DRT1]

i have .050mm bearings installed with a .076 clearance. So I think a 1.00mm bearing is needed to get clearance to .026. This is way off from what I was expecting to see since machine shop told me they milled the crank 020 over. They must have just milled it 020, not 020 over. The crank now must have 040 over mains. This is the only thing that makes since to me. I am not an engine builder though.

 

[charliemeyer007]

My Haynes says oil clearance on main bearings is 0.035/0.045mm standard to max 0.1mm. Bearing undersizes mm .25, .50, .75 and 1.00

 

[DRT1]

I have to pick up more parts from a machine shop tomorrow, taking the crank with me to get the main and rod journals measured before I purchase more bearings.

 

[DRT1]

Machine shop confirmed that the cranks main and rod journals are in fact .020” and .030” over std. The plasti-gage was not providing an accurate measurement. The .50mm main bearings and .75mm rod bearings that I have are correct.

 

[peesalot]

little loose, run straight 30 wt.