Early I. Pump Oiling

[wwheeler]

Not sure if this has been asked before and couldn't find it with the search. The early Injection pumps require manually changing the oil where as the later pumps have the forced oil supply. I also know the oil lines enter both pumps in different places.

So what is the purpose of the oil line on the earlier pump? Does it feed the front part of the pump only?

[ja17]

The oil line on the early pumps supplies oil to the IP cylinders. The oil, under pressure, fills a groove in each cylinder wall of the IP. This "ring of oil" forms the seal for the injection pump pistons (plungers) just like piston rings do in the engine. However, in the injection pump, clearances are in millionths of an inch, and the oil by itself,  is sufficient to form a seal.

[wwheeler]

Thanks for the reply and the explanation, Joe. I notice the two plunger pumps like on my 220 SE also have that oil line for the cylinders.

So the oil that needs to be replaced occasionally is just for the rear of the pump with the less critical components?  I have read about people with problems with fuel in the oil. I guess there must be a way it gets in there.

Thanks again,

Wallace 

[ja17]

Hello Wallace, I am not surprised that your inquisitive mind would request more information.  

The stored oil in the injection pump lubricates the critical camshaft and its followers in the bottom of the fuel injection pump. It also lubricates the mechanisms like the centrifical  fly weights, levers and pivots at the rear of the injection pump.  The critical compound cam and its follower are also lubricated by the oil stored in the injection pump. A second oil source from the engine, travels from the engine block, under pressure  via the small metal line. This oil forms the seal around the plungers to keep the gasoline from escaping past the pistons and mixing with the stored oil in the injection pump. As the engine oil becomes hotter, dirtier, more contaminated and less viscous, the "oil seal" becomes less effective small amounts of fuel begins to escape past the plungers mixing with the stored oil in the injection pump. When this happens the level in the IP rises above the "upper mark" on the dip stick. Oil pressure of the engine at an idle, also will effect the "rate of contamination" of the stored oil in the injection pump. As we know the later injection pumps have circulated engine oil supplied to all areas of the injection pump and fuel pump oil contamination is not a problem.

[wwheeler]

LOL

Joe, you know me too well. Just imagine what my wife has to put up with.

That is an excellent explanation and thank you. Hadn't ever thought about the loss of oil viscosity creating a domino effect. The oil in the sump and the stored oil in the IP on the 220SE is a bit skanky. Its fixing to be chnaged pronto.

[garymand]

Wallace, what is the +6 for on your 440?

[wwheeler]

That stands for 440 cu. in. with a six pack (three two barrel carbs). That car needs a lot of TLC.

[Novamonte]

That is one cool car! I read somewhere that they paid Warner Bros. 50 grand for the right to use the Roadrunner name and logo.

[ja17]

Oh, I thought the "6" was for six miles per gallon of fuel ! 

[wwheeler]

They probably did pay a mint for that. They got their money's worth because there are no less than 12 places on the car that reference the WB cartoon character. They even re-tuned the horn to sound like the RoadRunner. Beep, Beep!

Joe, that's 6 MPG on the highway after a good tune up and going down hill with a 30 MPH tail wind!