Truck Engine

In the 1950s years Cat wasn,t into truck engines till 1961 when the 1673 Truck engine came out & it was basically a D333 engine set up for a truck engine. The 1693 came out in 1964 & again was a reg. Cat engine used in equip. the D343 engine & was set up for truck use.It was their first really HD truck engine & was really a powerful engine in their day.I really fell in love with them from day one but the later truck engines were a little better on fuel & oil mileage. Packrat there should be some around yet for you to purchase & I don,t think you can go wrong putting one in your truck.

Thanks SJ, that's what I was looking for.
Packrat

Cat produced their first automotive style truck engine in 1939, with the release of the 6 cyl D468, a modified D4600. They introduced a 4 cyl version, the D312, in the following year, 1940.

Neither were a commercial success, as they were too heavy (being crawler engines originally) .. power steering was unheard of, and the weight of the Cat engines made truck steering a chore .. plus gas was still cheap and plentiful, and the gas engines were substantially cheaper to buy and overhaul.

WW2 production demand re-alignment, saw the D468 dropped from production in 1942, and the D312 in 1943.
Only a few hundred of each automotive engine were built.

Cat did not produce any automotive-type engine again, until 1961, with the introduction of the 1670, the 1673, and the 1693 models.
Cummins had the ascendency for truck diesel power in the 1940's, and 1950's, with Detroit Diesels making inroads into Cummins market share in the 1950's. Cat did not make a serious assault on the truck engine market again until the mid-to-late 1960's.

Hi Oz, Have you got any pictures of the D468 and D412 engines you could share with the board. I would imagine both engines were direct electric start. If so, then why was direct electric start not available on crawlers and graders until much later?

dozerman51 - Yes, the Cat automotive engines were electric start, and the marine engines were also mostly electric start in the mid-to-late 1930's.
The marine electric start system is understandable, as the temperature extremes in that application would not be as large as on land.

However, the Cat automotive engine engine was equipped with a 24V starting system, and a 12V lighting system (a not-entirely-satisfactory, and complex system, that has been used by European and Jap truck builders, and which I have plenty of personal experience with .. 😞 ) .. and the D468/D312 user was warned, that the electrical starting system was designed only to start an engine in good mechanical condition, and at temps of 50°F and above.

Cat warned that ''some provision will be required to heat the engine to the above temperature for satisfactory starting'' .. and the Cat truck engine owner was left to his own devices to figure what that heating system might be .. on any particularly bitterly cold, Winter night, or morning .. 🙄
Another nail in the coffin, of Cat truck engine sales, in that era .. 😞

Armed with that warning .. it's easy enough to see why Cat, and many owners, much preferred the pony start for the crawlers and graders in the 1930's to 1950's.
With the poor quality batteries .. that were heavy, and had low cranking output, in that era .. the pony start definitely had many advantages for starting tractors in the extreme cold of the North American and Canadian winters ..
You didn't have the problem of battery failures, which was a lot more common in the 1930's and 1940's .. plus, with a pony, you could leave a tractor for months, and come back and not have to worry about charging flat batteries ..

Here's a pic of the D468 .. I have not yet found a pic of a D312.

http://img249.imageshack.us/img249/4581/catd468gi5.jpg

The D468 commenced production at S/N 1N3001. It featured an all-new 'automotive type' governor, a front mounted crankshaft vibration damper, a self-contained water pump with replaceable spring loaded seal, electric start, a choice of Midland air compressor, or Bendix vacuum pump (both, belt-driven off the rear of the gear drive generator), SAE bellhousing with a Spicer single plate clutch, and a Spicer 5 speed overdrive transmission.

The "new type automotive governor" must have been a relatively poor design .. because only 73 engines were built, before a new design governor appeared in Jan 1941. This new style governor was also fitted to the D312.

Packrat you were only interested in an engine to repower your 50s KW so the old antique D312 & the D468 wouldn,t be what you,d want in it.I never even saw one but have some specs. on them & the 312 was only a 60 HP engine & the tops for the D468 was 100 HP.Also the 1670 was the old D330 4 cyl. engine also used in equip. but was setup for a light truck engine . They were only rated as a stop-go engine & for inter-city duty so it wouldn,t be for a KW HD truck as they were only rated at 165 HP tops for it.The 1693 didn,t come out for a couple years after the 1673.Packrat the 1693 engine would be what you,d want or even the little later 3406 that replaced the 1693 as both were used in the KWs.