Caterpillar 75 Diesel cold start

Starting a 1935 Cat 75 Diesel with it's pony motor.

Category:

Autos & Vehicles

Tags:

• Caterpillar Tractor Co.
• diesel engine
• antique tractor
• crawler tractor

[floodedcar123]

I love old pony motor starting cats.

[pilot96732]

Many of the people, who are starting these old pony motor tractors do not follow the correct procedure. This will eventually severely affect the length of life of the Diesel engine.

1. After starting the pony motor, engage the pinion and turn the Diesel slowly at first with NO compression and NO fuel to the injectors.

2.  Only after the Diesel crankcase oil pressure comes up, speed up the pony engine, along with the Diesel.

[RomeKG7E]

This tractor was completely disassembled and rebuilt. I had new 5 1/4"x 8" liners made for the engine, new valves, springs, cam followers, new precombustion chambers made. all new bearings in trans and finals. runs and operates like new.

[alecluke844]

my grampa has 2 rd6 an rd7 and a d8 chicago knumatic compressor with a 13000 d8 engine i start them all the time its fun

[RomeKG7E]

@pilot96732 Thank You. I agree with you too.

[pilot96732]

My purpose was not to jump on you, for which I apologize. But, it pains me, when all these people are abusing almost all of these really fabulous old machines. Caterpillars are one of the best examples of incredibly high quality American manufacturing. These tractor really had no design or manufacturing flaws. They are known as the best tractors in the world. Just compare their quality to cars made here now. No one can. These were meant to last almost forever. Cars are meant to wear out.

[RomeKG7E]

I was well aware I needed to run it longer on compression, I never try to start it right away like this and also mentioned six months ago thats what I wanted to do but the film crew was in a hurry. Any other time I do just as you stated in your starting procedures.

[pilot96732]

@RomeKG7E Not long enough. It would have started on all cylinders, if you had turned it under compression longer. The intake air was not heated by the pony exhaust yet. The repeated re-engagement of the pony motor clutch can be avoided this way, too. This re-engagement will wear out that clutch quickly.

[RomeKG7E]

Just wanted to note that the engine was turning under compression a short while before I opened the throttle. At the moment this started to be filmed I just previously opened the throttle to start it.

[pilot96732]

ALL engines wear the most and the most quickly during each start-up at less than full operating temperature. These procedures were taught to me by a man,who owned a heavy equipment company with five Cats (3 D7's and 2 D8's in the early sixties. They were great pleasures to operate, partly due to their reliability. If an operator was found to ever not follow these procedures to the letter, he was in trouble for his job.

[pilot96732]

5a. (somehow lost in cut in paste) If the outside air temperature is above 50 degrees or if the tractor has been run that same day, you can skip the half compression step.

[pilot96732]

7. NEVER rev the Diesel more than 1/4 throttle, until it has warmed to full operating temperature. Your CAT will last and last and last with this treatment. If you apply fuel sooner, it will not last at all as well.