Cat 1673 engine....

is that a v8??
if so its amost similar to a cat 3208 ( v8 )
those were called the trow away engines from cat,
quality just so so, and not so much in comparison to very good 33 series (3304/3306) and 34 series. 3406-08-12

inline six dual overhead cams. i had a 1693 in a truck a looong time ago.loved that engine. the 1673 is it's little brother

What did Cat supply as a 4 cylinder when the 3400 series reigned?

Hello
Caterpillar 1673 truck engine is similar to D6C track type tractor, No14 motor grader and D333 engine.
The 1673B was a 6 cylinder 4.5" bore X 5.5" stroke, 525cu/in @ about 245 Hp. ( 2 valve head ).
The 1673C was a 6 cylinder 4.75" bore X 6" stroke, 638 cu/in @ about 250 or 270 HP. ( 2 valve head ).
The 3306 was a 6 cylinder 4.75" bore X 6" stroke, 638 cu/in @ about 250 or 270 and 300 Hp. ( 2 valve head ).
The 1674 was a 6 cylinder 4.75" X 6" stroke, 638 cu/in overhead cam @ 270 Hp ( 4 valve head ).
Down here they were all used in Oshkosh trucks, i.e. R,s and E models.

Best regards

I have one in a 9u D6 farm cat,real nice engine.

EL300B, can you post some photos of that 9U - it'd be interesting to see how it's fitted and what accommodations were made

The farm I helped out on had a KW with a 1693. The first time I drove it, and the turbo spooled up, it sounded like a cop had hit the siren. That turbo was loud.

1673C was the same engine as the D333C/3306.