Basic OM616 questions
 

Dear all,

Being a newbie, I am unclear about

1) Why is it that IDI engines have more compression ratios than DI engines? If IDIs sacrifice mileage/torque for smoothness and accleration, I would think that the compresson ratio needs to be the same if not lesser than DI

Can some one post a pic of the cylinder head? Is that the place where the pre-comb chamber is located?

2) Is the design of the IDI pistons different in any way as compared to the DI pistons?


3) Why do TC engines have oil spray and NA engines do not have them? Why is it that the combustion temps are more on a TC engine? If one has an Intercooler , by how much does it reduce the need for oil spray. I am asking this question because I have an acquaintance who wants to get a normal OM616 and wants to TC it.

4) How does the diesel engine (OM616) shut off when I turn off my ignition key? In my tractor, I had to pull on a decomp lever that will essentially open the cylinder head to atmosphere pressure/temperature and cause combustion to cease. I thought diesels did not need electricity / circuits to run.


And generally any pictures you can post of the mechanical aspects will be much appreciated.

I'll take a crack at some answers,
3) The reason for the oil spray is to cool the piston. More power means more heat. Too much heat and the pistons melt. Spraying oil on the underside of the pistons hepls to carry away some of the heat. Adding a turbo to an non turbo engine results in shorter life. If you limit the boost, it will run longer, than with full boost, but the better answer is to get a turbo engine to start. There are U pull it junk yards around Baltimore that charge $150 for a complete engine ( unless the prices have gone up), plus some extra for the turbo--you could probably get the whole thing for under $300.

4) Diesels need only fuel (and compression) to run, dump the compression, as on your tractor, and it dies. Cut the fuel and it dies. Mercedes chose to put a fuel shut off on thier cars. It is usually vacuum operated from the ignition switch.
Ford used an electric solenoid to shut off the fuel in its diesels. No fuel= no run.

The precombustion chamber is in the head.

the injectors screw into them, to remove it requires a slide hammer(dont forget to remove the glow plugs)

They have higher compression because they can. Higher compression runs more efficiently. This is what developped the power on early diesels. Newer diesels get their power from the boost provided by the turbo. The compression difference is more than made up for by the boost pressure. IDI engines are usually 21:1 to 22.5:1 and can tolerate 6-12 lb boost before the pressure gets too high. Modern diesels are usually 18:1 and can tolerate boost pressures in the neiborhood of 20lb to 30lb in some applications.

You're not going to find an MB turbo 616. MB never made them. The only place you can find them is in India where Force Motors (Tempo?) got the license from MB to build a turbo version. They are still building them. There was a recent thread about them.
Lots of people have put an aftermarket turbo on the 616, particularly in Europe where the 616 was a very common motor in trucks and motorhomes. I've talked to a man in the UK who did it to his motorhome and was very happy. I have no idea what kind of boost he was pushing and how long the engine lasted. Motorhomes tend not to accumulate lots of miles so perhaps it's a moot point in that application. I've posted a link in the past to the UK company that specialized in turboing the 616.

Sir,

I currently own a Turbo OM616 manufactured by Force motors.

Ram

240 td
 

I thaught europe had the 240TD with a 616 turbo. I've seen one of those here locally.

Not made by MB. Must have been aftermarket.

A 240 TD is a W123 wagon powered by the 240 D engine. The TD means diesel wagon, just like on a 300 TD.

the T stands for Touring=wagon in us english and Saloon= sedan in us english