617 vs 602
 

Can anyone tell me how a OM602 compares to a OM617? I'm looking at buying a G-Wagon but I am not familiar with the 602 other than it has a lower max HP.

I am familiar with the 617 presently owning 2, one non turbo, the other turbo. Are parts a problem with the 602? Is it as robust as a 617? Any inherent probelms or defects? :confused:

The 602 is one of the old "new generation" iron block/alloy head engines. Actually the normally aspirated 602 produces quite a bit more power than the normally aspirated 617, and the turbo versions of both were about the same in output.

I've seen two HP figures for the n.a. 3.0 liter 5 cylinder 617: 77bhp and 83bhp.

The n.a. 2.5 liter 5 cylinder 602 was rated 93bhp

The turbocharged version of the 617 was rated 120bhp, while the turboed 602 was 121bhp.

The 602 appears to be a long lasting engine, with only a minor problem with the hydraulic lifters. It seems that they either start to go bad, or some o-rings in the oil filter housing dry out... in both cases, intermittent valve noise results. It is just an annoyance, though it probably does affect maximum performance.

Overall it is lighter, quieter, more fuel efficient, cleaner, and has a better inherent HP-to-displacement ratio. Its just technology and evolution.

However, it is not as ultimately robust as the monster 617. Care must be taken not to overheat a 602 because the heads are apparently quick to crack under such conditions.

-Joe

Thanks for the superb response!!!! It was just the kind of info I needed.

However, I do have one more question. The horsepower values you gave appear to contradict values given for specific vehicles with different engines. I am looking at a 1985 G-Wagon 300GD with a 617 and it is rated at 65KW/88Hp, a 1987 300GD with a 602D25 is rated at 62KW/84Hp. Is there anything to explain the difference?

PS. the differences in Hp between the two engines is insignificant to me but I am curious. I would think your values are more correct given that the 602 is a newer design and one would think that if the designers went through the trouble of making something new that they would get more Hp out of it.

Hmmm, I'm not sure on that one. The figures that I quoted were the ones published for the engines as they were used in passenger cars... namely the W123 chassis, the W201 chassis, and the early 90s W124, all in the US market (which I assume covers all of North America)

If your values are correct for the G-class, it may be explained by a different exhaust system or intake manifold design. The 602 as used in the W201 has a tuned length intake manifold, for example.

-Joe

Also, keep in mind that the 617 diesel is not computer dependent..sensors, relays, etc.. for it to run. The 602 engine is computer dependent. They both are very good engines. The 617 may be less of a headache due to it not being dependent on using computer components for operation. Just my .02...