Packard Forum Index » Pre-War (1899-1942)

Many of you will know of my mate Wade, as I've previously written extensively about him and his workshop in my Project Blogs, but now he needs some help. Wade is currently working on rebuilding a '39 120 engine for one of the members of our Packard club. The engine has been to the machine shop for cylinder honing, crankshaft grinding, etc. With the crankshaft also being straightened!

But When Wade came to reassembling the engine, he got no further than installing the crankshaft with the new bearings. Then the crankshaft wouldn't turn! After dissasembly, it was back to the machinist who found the main bearings were not properly aligned. However Wade hasn't been able to find the spec's for the size the main bearing tunnel needs to be.

In order to realign the main bearings, the caps need to be surfaced, then the main bearing caps and block need to be Line/Tunnel bored back to spec.

Accordingly, can anyone please refer us to a source of the measurement required to Line Bore or Tunnel Bore a '39 120 block?

I don't have a direct answer but until one is forthcoming, why not tighten one cap and measure the diameter? That what shops typically do when line boring.

The bore spec would be 2.936"

Thanks
James From
Kanter Auto Products

James,
from both Wade and myself.

Don,
for the suggestion. If James hadn't come up with the spec we'd probably have given that a go.