Dave: Some of the younger people on YouTube mechanically inclined ones have been asking me questions how a diesel engine can also run on gasoline? Well as far as I know in North America the only company that sold bulldozer as equipment like that that had a dual engine was international or international harvester in 1968 the company was bought by Dresser so I will give a quick explanation in fact it's very simple. This dozer is a 1953, it weighs 20 tons, it got a 12 foot blade every thing is actuated by hydraulics and it was a biggest dozer back then. Well like all diesels you have to have some sort of injection system, this has an injective your pump and a little tubes at the top for the fuel outputs it go to heat injector along there in the manifold.
Unlike most diesels, the fuel injectors these things are in between the area where the exhaust comes out. You see they are far away from the exhaust manifold whether inside the head underneath the rock recover. Some diesels don't have that big fuel injection pump that no runs a whole system, they have individual injectors underneath the rock recover that run off the crankshafts everytime the lobe goes around and pushes on one its -- some fuel. This injector pump has a shaft that comes out this driven off the engine.
Those two big boobs like looking cylinders are the containers to hold the cartridge style oil filters. And these two smaller perky boobs are the containers that hold the cartridge style diesel fuel filters. Got love them and that big yellow box is just a air filter box and there is actually oil in there which is a good thing it helps to keep everything wet so that sticks to the dust. Now having the system like this is a huge advantage but is more expensive to manufacture. The huge advantage is it doesn't need to be plugged in and warmed up overnight with a block during the winter time and doesn't need a big battery to crank over all that high compression.
When you pull this black knob, it actuates its lever and it pulled up really hard it locks and clicks. Well that goes right into the block of the engine and in the block of the engine is in extra valve, like an old flat head engine has and below that valve is just empty pocket. The pocket just a extra volume container, extra volume meaning that when you pull that lever the effective space above the piston in the cylinder head becomes larger, thus reducing the compression ratio and normal diesel needs at least 500 PSI compression to run but a gas engine only needs a 120 to run a gas engine on high compression well then it ignites the gas before the piston gets to the top and it's lighted with a spark and then it pushes the piston back down the wrong way and things just don't work, so now we are on the opposite side of the engine.
This engine happens to be 700 cubic inch sixth cylinder straight block. So on this side we have an intake manifold. This manifold above is just cooling manifold you know and freezes in there. Well this intake manifold is a little key part at the bottom which most intake manifolds wouldn't have and has an old small one barrel carburetor. There is a throttle for it, it has a chock and it has a fuel feed and there is the feed bulb or the filter bulb. So in here to put regular gasoline and in there the 75 gallon tank put diesel behind that carburetor just an old fashioned six cylinder pointing in as distributor, an ignition coil. There is the choke. So the way you started to shut off all the diesel fuel by putting that liver at the bottom, that's the throttle. When you pull that black knob it also activates a switch, when it decompresses the engine and the switch puts 12 volts to that coil then its starts making spark.
So up underneath that intake manifold is just some ordinary car spark plugs. Diesels runs at wide open throttle all the time just no throttle plate so this engines runs at wide opened throttle too but the neck of the carburetor is so small that it doesn't allow it to run that fast, so while you are pushing that started button to crank it, pulling that knob to decompress it, pulling that knob to choke it. It fires up on gas. It runs just fine on gas. Doesn't have any power you can drive it which it cant push dirt.
Then when the engine warms up you know 2 to 5 minutes in the winter time or just about 30 second in the summer time. Then you release the high compression knob that this knob add some diesel to that next here I mean to the injectors and she is running on diesel and of course the spark is shut off soon that knob is released simple is that. The other method bulldozers using stuff like this would often use as what called pump starts, so at the back of the engine. There will be you know one or two cylinder gas engine could be anywhere from 5 to 25 horsepower. You would start that up first then engage the starter drive to the fly wheel and it would get your diesel cranking around fast enough no matter, what the weather was it would eventually start.
There is another system too that use on some big engines including 18 wheelers and stuff and that's called the compressed air start, they just start ramming compressed air and while the engine is cranking that's helps push the piston around make more compression and that starts engines too. In the winter time my dozer just like now, sits outside in the field suffering from all weather conditions, motor buried in snow no care whatsoever and it all starts and I use the plans no with the farm, so this place just couldn't be the place it was and use today unless we had a dozer to prove the line jumps and be able to get in here and park our cars off the road and enjoy winter fun too and try to start this thing in your battery happens to be dead in your dozer well.
You just pull the battery out of your car and so an ordinary size car battery in here and it fires at rate up that's all I use the car battery. Every other machine like this has a huge battery, got love your American muscle.
Transcription by:
Scribe4you Transcription Services