Are BMW actually a joke how smart they are?

[PhillipM]

As many have said, really common, it was old tech when I was in school/uni, think it originally came from some of the WWII fighter engines, which were experimenting with many ways to locate rods without strength reducing dowels.

[E-bmw]

stevieturbo said:

bolide said:

I would think the main advantage is that you can machine a perfectly round hole for the bearings, rather than machining two half-round parts

What ?


Rods are machined round assembled, the bearing hole is not machined as two halves.

I think what he was meaning was using broken rods means that is true, using non-broken rods would mean that you would have to make 2 halves to be exactly the same and then additionally machine dowels etc.

[Megaflow]

E-bmw said:

stevieturbo said:

bolide said:

I would think the main advantage is that you can machine a perfectly round hole for the bearings, rather than machining two half-round parts

What ?


Rods are machined round assembled, the bearing hole is not machined as two halves.

I think what he was meaning was using broken rods means that is true, using non-broken rods would mean that you would have to make 2 halves to be exactly the same and then additionally machine dowels etc.

Non broken rods are machined as one piece as well, the only difference is pre machining the faces of the cap and rod before they are assembled and the bore finished machined.

[HJG]

Yes, connecting rod big end are final machined with the bolts tightened to production spec. This is why when some go and put super duper bolts in and tighten them to a million Nm, that the shape ends up all over the place.

[E-bmw]

Megaflow said:

E-bmw said:

stevieturbo said:

bolide said:

I would think the main advantage is that you can machine a perfectly round hole for the bearings, rather than machining two half-round parts

What ?


Rods are machined round assembled, the bearing hole is not machined as two halves.

I think what he was meaning was using broken rods means that is true, using non-broken rods would mean that you would have to make 2 halves to be exactly the same and then additionally machine dowels etc.

Non broken rods are machined as one piece as well, the only difference is pre machining the faces of the cap and rod before they are assembled and the bore finished machined.

Yes, I know they are made as 2 halves and then joined together & then finished and (although my description may have been slightly simplistic) that still means you have to make 2 things rather than one, even if you then bolt them together to finish them.

Much better to just fully make one thing in one process.