Out of interest. This is the middle main bearing. It’s done about 40 miles so far. Is this how it should look after that distance?
The crank looks ok. Shiney and even. I’m guessing it’s seated properly. I have literally not had an in-depth look at everything properly yet.
Oil starvation? My bearings looked like this after less than 1,00o miles and periodic plummeting oil pressure. Note the groove right around for oil supply. I don't know much about bearings but noticed yours doesn't have that. Any sloppy big ends?
Yes. I have been looking at things, as they came apart, but when I split the case, everything just fell apart, as I don’t t have the luxury of a proper engine cradle thing. I just did it horizontally on a flat table.
Ok, I see what you mean. The big ends seem ok, no sideways movement that I can tell, anyway. Like I say, I Havnt really checked things thoroughly yet,mas I have to get stuff ready for work tomorrow.
Hi. Re, the main bearing. I just wen and searched for a pic of some new ones, and noticed that they don’t have the centre groove in them too. Is the chamfer bit at the top and bottom, the groove bit? Perhaps the oil goes into the chamfered bit and spreads evenly over the journey of the crank? I don’t know…I’m just guessing…
Bolted like this and also snout was very loose where it should very tight in the case. If your problem is oil starvation it won't be the same cause as mine.
Have your centre bearings got any oil holes at all, that match up with the oil galleries/holes in the case?
For info (if I remember correctly) oil is fed from the hole in the centre of the case web, up/around the channel on the outside of the bearing shell, then out to the crank through the "scoop holes" in the shell. Forget the above "matching up" bit.
For what it's worth when I stripped it I just went crazy ape on the workshop floor, I had a strong feeling I'd be starting again which only got stronger as I took it apart to find what the knocking noise was. On the way found 4mm or so deck and semi-hemi heads (not stock that I supplied), then a stock cam (should have been C35 I supplied) so by then all bets were off and I was hunting for parts I could use again. The case and crank made it, the rest binned. Rods, pistons, cylinders, heads, cam and followers, oil pump, oil pickup, bearings all unusable. If I missed anything off that list it was also binned. Even that oil thrower washer thing!
Mine were odd then looks like. They might have been type-4 bearings, or wasser bearings, I remember having to buy 2 sets of main bearings and using some of each.
If the other shell doesn't have a hole in it, I can't see how oil can get to the crank from the oil hole in the case.
Yes. I think they have.Ill know better tommorow when I look properly, but I know they have other holes in them, as Imreseated the crank back onto the pins,and noticed extra holes in the bearings. Smaller holes, than the location pin holes.
But I still don’t know where the debris in the original pic came from. There is simply no sign of any damage, anywhere, which I am pleased about,at least.
