First year for Insert type main bearings in Buicks?

[Guest]

A member of our local car club owns an original 1929 Buick with the OHV 6 engine. He tells me that the main bearings in the car are the original and that they are of the insert type and not the babbitt type. I didn't think the insert type came out until the mid 1930s. Could I be wrong?

[Guest]

my 1930 has babbits, so dose my 1950.

[Matt Harwood]

Dynaflow-equipped Buicks first got insert bearings beginning sometime in 1948. The rest of the lineup got them sometime after that. But that isn't to say that <span style="font-style: italic">all</span> Dynaflow-equipped 1948 Buicks have it--they started switching over after their supply of babbited bearings had been exhausted sometime through the model run.

To answer the question, no, your friend's '29 with insert bearings is <span style="font-style: italic">not</span> original.

[Guffin]

Buick didn't use insert bearings until (ca?) 1950 in the 263,3 cid engine. The main bearings before that, was not what is called insert bearings. You can remove them but the babbit and shell was much thicker. Opposite to insert bearings you couldn't buy the old type of main bearings in correct dimension. They had to be line bored in place.

Jan

[old-tank]

A week ago I helped Bill Stoneberg with the engine from his '47 and it originaly had inserts for the mains and babbit for the rods. Even though the mains had inserts, shims were used to adjust clearance liked babbit bearings.

[Guffin]

Old-tank, I think you mix up old type of removable bearings with what we today call "insert bearings". Modern inset bearings have a very thin babbit layer. It is too thin for using shims for adjusting clearance. Buick began using modern type of insert bearings around 1950. It is possible to modify old rods to take insert bearings. I have done that on my 1929 Hupmobile.

The thick babbit layer on poored bearings has a tendency to crack and pieces get loose which may cause the bearing to over heat.

Jan