Appeal of 4-cylinder diesel vs. 5-cylinder - PeachParts Mercedes-Benz Forum

Raptelan · #1 07-06-2012, 09:54 PM

Hey all,

Just looking for some opinions on what the appeal of the 4-cylinder 615/616 diesel engines is, assuming the same chassis that also came with a 617.

I've got a W123 200D that probably needs an engine rebuild, and while I really enjoyed the uniqueness of the car, I looked up production numbers and found that they were actually quite common in europe. I bought it expecting great fuel economy (I used to get over 40mpg consistently in a W115 240D, but it just failed to deliver that. I looked up the specs and it was only rated at 0.1mpg more than a 300D turbo.

So I understand why people bought them new - I'm sure the purchase price was lower. But with no real increased efficiency, and half the horsepower, what is the appeal of these cars compared to their more powerful counterparts? I'm thinking it might not be a bad idea to swap in a 617 turbo engine.

kerry · #2 07-06-2012, 09:57 PM

Some European countries tax cars on the size and horsepower of the engine. Hence the appeal of small sized low horsepower engines.

PackerEdgerton · #3 07-06-2012, 10:59 PM

Quote:

Originally Posted by Raptelan

Hey all,

Just looking for some opinions on what the appeal of the 4-cylinder 615/616 diesel engines is, assuming the same chassis that also came with a 617.

But with no real increased efficiency, and half the horsepower, what is the appeal of these cars compared to their more powerful counterparts?

In a word, simplicity.

The W123 240D, especially with 4-speed manual, is truly a Zen mentality automobile. As simple and elegant as the 617 is, the 616 is even more simple. No turbo. No fifth cylinder and associated "harder to adjust" 5th set of valves. 1 less connection on the injection pump.

No ALDA. No vacuum controlled tranny (with the 4-speed manual).

Plenty of room in the engine bay. Everything is logically placed and easily accessed.

Less complicated. Less moving parts. Less to break down.

Less is more.

Once you adopt the mentality that you will never beat anyone off the line, and embrace the fact that you are not moving really fast, with really neck-snapping acceleration, but accept that the 616/240D will always always get you there safely and surely, albeit slowly, you will start to learn the Zen nature of the combination. 67HP, 3300 lbs of tank. Yep. That's the ticket.

I think that the 617 and the 617 turbo are truly great masterpieces of German engineering.

I think that the 616 is even more so.

There is more to life than increasing its speed.

-Packer

Raptelan · #4 07-07-2012, 12:25 AM

Well there's definitely room in the bay... The car also has manual tranny, climate control, windows, and sunroof, and I've got manual-adjust euro headlights to install too. It's only 59hp actually, but that's plenty enough. Actually it makes a 240D look bigger and more complicated. I wanted to replace the 3.92 diff with a 240D one, though... But rebuilding the OM615 will probably cost more than buying a good OM617, and I'm not sure there's much resale value in the project...not that I'm in any hurry to sell it.

charmalu · #5 07-07-2012, 01:12 AM

I have the 85 300D with 123HP, sure it pulls the hills faster and more get up and go from a stop. with the 4-spd manual trans it get 29 - 31 mpg out on the Hwy.

The 80 240D with 67 Hp is a little slower on the hills and slower leaving a light. It also has a 4-spd manual trans. and usually get 30mpg with general running around. once in a while might drop to 29. on the Hwy with our last long trip got 33.5 mpg doing 65 - 70.

Between the two cars, there really isn`t all that much difference in the total amount of time getting to a destination. I like both cars, but the 240 sure is a fun car to drive. It will stay a 240 if time to ever do something with the engine. I like the simplicity of the 240 with the manual climate system over the automatic one in the 85, manual window winders, no sunroof. doesn`t get much more simplier than that.

As far as to swapping in a 617 engine over rebuilding the 615, that is your call. every one has their own opinion as to what they would do. You can pull a PNP engine for around $300, rebuilding your 615 will be a good $2500. I saw one last night on CL out of a 80 300SD, 160K miles for $800. as time goes on, it is getting harder to find good engines whether 616 or 617.
I lucked out 4 yrs ago in PNP, got a 617 out of a 84 300D that got rear ended and shoved into another car. so knew it was a driver at the time, and 97K miles. so they are out there, If you are not in a hurry, one will come along.

If you install a 617 turbo, then up grade the diff to a 3:07 or a 2:88.

NO the engine is not for sale.

Charlie

t walgamuth · #6 07-07-2012, 07:39 AM

What has been said previous in this thread has really covered it well and elegantly.

I have had a lot of these 123 cars both with the four cylinder and the fives. I currently have one running with the five euro non turbo motor which also has a 307 diff and the five speed od. It is a truly sweet combination, will run as fast as you want on the highway with very low engine noise and will deliver 35 mpg with regularity, a couple of tanks have delivered 40 mpg.

I also have experience with the five turbo with a stick in the 123 body. It will deliver high twenties with consistancey.

I have had about a dozen four cylinder 240s, nearly all with stick. The 240 with automatic is just too slow for me to contemplate driving.

I like the 240 just fine around town and for short highway trips but if you need a car for long trips the five cylinder either na or turbo is the ticket along with the 307 or 288 diff.

If I had your car i would not rebuild the 200 but would go with the 240 version if town driving is the main thing and only occasional road trips. If you want to make long trips frequently I would convert to the five cylinder engine either in na form or turbo.

All the versions of the 616 617 are virtually bulletproof if put right to begin with. The turbo motor too but it has the added complexity of the turbo so it will cost a bit more to put right if the turbo is not up to snuff.

Charlies estimate of 2500 for rebuilding the four cylinder motor should be considered a minimum, I think. I also don't think it will cover any professional help for the installation and removal of your existing motor.

barry123400 · #7 07-07-2012, 09:36 AM

Personally I like the handeling with the lower weight of the four cylinder power package with the manual transmission. If you drop a five cylinder in you will pretty much want to change the rear end ratio.

If you anticipate a lot of highway travel that package is both quieter and faster. Even though the primary chassis is pretty well identical they feel like two different cars to some extent. Or at least to me they do.

The four cylinder cars are more of a cult thing I suppose as well.

charmalu · #8 07-07-2012, 09:39 AM

Tom, your are right me being on low or conservitive side of the cost of rebuilding the 616. I might have been thinking of just the parts. Taking the car to a shop and having them R&R the engine and also rebuilding it will make the cost considerably higher. Doing some of the work your self will lower the price.

Pulling the engine your self is not that big a deal. Living in an apt complex type situation or Heaven for bid, an (HOA) Home owners assotiation,

will make it a more difficult job to DIY.

Having a shop do the work, better find one that knows these engines, and has a good reputation. I think a Metric Motors 616 engine is up close to what a 617 long block is. I paid $6000 for the 617 long block, and think they are up to $7800 now. It comes with a 4yr 50K mile warranty, rebuilt IP, Injectors.

Rebuilding a 616 617NA, the parts will be similar in cost except for one more cylinder for the 617. the 617 Turbo will be quite a bit more in the cost for parts.

That might be a high price for an engine for an "Old" car, but that engine will follow me around for a loooong time. whether it stays in this car or goes into a couple others.

I would rather have a good engine in a beater, than an "Iffy" engine in a pristeen looking car. we use our car for long trips, and I want at least the engine getting us there whether other parts of car follow us all the way.

Charlie

Raptelan · #9 07-07-2012, 12:31 PM

It's a 615, not a 616. Quote from metric motors is $6350, plus shipping both ways at another $700. I could take time to learn to do it myself but that would mean buying more tools, etc. in addition to parts, and the MM end result sure looks nice. On the other hand I'm not in any hurry and buying the tools and learning means I could rebuild more motors. I've got a 617 turbo with about the same issue and a 617 NA which needs a crankshaft replacement, so...

Spare 617's are easier to find at junk yards. The 615/616 are perfectly adequate for getting around, but the 617 is more fun. The NA is considerably quieter/smoother, but that may just be because it has 80k miles versus 200k+.

I commute 2 hours each day, but mostly on state highways so not doing any more than 65 generally anyways. Currently stuck using a D-jet 450SE as my daily driver (read, 10-12mpg).

kerry · #10 07-07-2012, 12:38 PM

One thing that makes a significant difference is altitude. Even the 617NA gets to be a dog at higher altitudes. I wouldn't buy a 615/6/7 NA for daily use as I live at a mile high. Having the turbo is like having a second engine at 10,000'.

charmalu · #11 07-07-2012, 03:05 PM

Quote:

Originally Posted by barry123400

Personally I like the handeling with the lower weight of the four cylinder power package with the manual transmission. If you drop a five cylinder in you will pretty much want to change the rear end ratio.

If you anticipate a lot of highway travel that package is both quieter and faster. Even though the primary chassis is pretty well identical they feel like two different cars to some extent. Or at least to me they do.

The four cylinder cars are more of a cult thing I suppose as well.

Barry, I totally agree with what you said here.

Charlie

charmalu · #12 07-07-2012, 03:13 PM

Quote:

Originally Posted by kerry

One thing that makes a significant difference is altitude. Even the 617NA gets to be a dog at higher altitudes. I wouldn't buy a 615/6/7 NA for daily use as I live at a mile high. Having the turbo is like having a second engine at 10,000'.

Kerry I think you know the Vail, Keystone area pretty well, and the high altitude.
We had the (Cali) 85 up there several years ago with trap oxidizer set up as the Cali come with. There was no acceleration, probably much like a NA617.

The next year we were up there, but we changed thing to the way an 83 is. Talk about a second engine. thought I was in a Corvette.

was like night and day. and this area is right up around 10,000 FT.

Yeah, as long as you drive around the flat lands or near sea level, a NA engine will do well. start getting up to 3000ft, and you start feeling the power drop off.

Charlie