Mercedes: Water injection, compression engines, catastrophic failure

Question
QUESTION: Rob, I have a 1976 300D Mercedes with 170,000 on the clock. I fitting water injection to give it more power, but I wonder how i will suck the vapour into the inlet manifold? Could i use the rocker cover breather pipe, or will this blow the rocker gasket because of too much pressure.
Regards,
Doug.

ANSWER: Doug,
I would research the subject on google. There are video showing the injection point in the air intake.
Under no circumstance would you install water injection in the rocker cover, as this is not related to the air intake and would just pump water into the oil and cause catastrophic failure of the engine.
Rob


---------- FOLLOW-UP ----------

QUESTION: Thanks Rob, but I wasn't going to put the water into the rocker cover. I was wondering if the pressure from the breather pipe would be too much to put into the air intake as diesels do not have the same pressure as petrol engines. If it does generate too much pressure then how can I force the water vapour into the air inlet.

ANSWER: Eoug
Try this web site for info. There is a diesel explanation regarding using the valve cover as a pressure point.

http://www.greaseolineplus.com/page2.html

Good Luck
Rob

---------- FOLLOW-UP ----------

QUESTION: Rob,
Thanks for the info on the diesel setup, I'll give it a try. One last question; Is water injection good for the engine, and why doesn't every vehicle [diesel & petrol] have it if it is so good?

Answer
I expect that convenience is probably an issue. Additional water tank and source and equipment. If a balance is not maintained then you could get performance similar to that associated with water in the gas. Hard starting and even skip if you use a spark ignition.

Usually water injection is used to improve emissions and efficiency on HIGH Performance high compression engines, particularly on turbo boosted engines.
When you pressurize the air coming from the turbo it gets hot. Hot air is thin. Thin air does not have the correct burn ration for good fuel burn. The water misting lowers the air temperature and makes it more dense. The dense cool air enters a hot cylinder and allows for better fuel burn with lower carbon and other emission.
Rob