Would an OM617 non turbo rebuild thread be worthwhile?
 

G'day Folks,

I've recently been rebuilding the engine on my 1981 W123 300D - that's an OM617 non turbo engine. As I'm in the habit of taking lots of photographs as I work I've got quite a few that could be made into a thread if it was felt to be worthwhile...

If the general consensus is that people would like to see this - I'll make the effort - otherwise I won't bother!

I think its a great idea!

The N/A shares many assebly steps that are identical I would think to the Turbo motor, differs mainly in the Oil-Pump area--For Assembly Purposes anyway....;)

Wow you're quick Alastair - I've turned it into a poll - partly because I've been itching to do this for ever!

Oh by the way if anyone isn't happy with the choices in the poll - please feel free to ***** about it as much as you like - but remember I can't do anything about it now!

I voted yes but I don't have the non-turbo....just like seeing lots of pictures of projects.

I think it will be interesting. Honestly, I will never take the time/effort to rebuild one myself; but I would like to see the process.

Id be interested in seeing it even though i dont have any NA engines...

Army,
Having followed your progress with your rebuild, you would be doing the site a service to write up such a thread.
Your perfectionist approach to the rebuild would put many experienced re-builders to shame.
Bringing your many threads together into 1 will be quite a task !!

The importance in my opinion is the financial lower cost to properly rebuild the N/A engines versus the turbo varients. Post costs as you go along if practical and you have not already.

Aftermarket german pistons standard and oversize at reasonable prices in comparison to the turbo pistons account for a lot of this in my opinion.

I think it will be very helpfuyl and add to the value of the document base.

Your survey doesn't include a spot for "YES, even tho I don't own one" so I didn't vote.

I feel disenfranchised. :(

If your just posting up pictures. Then it's just another pictorial.

But if your going to go through the process i.e. explaining the measurements, how parts are fitted. Then that would be different then the other threads.

layback40 - you make me blush.

barry123400 - If it goes ahead I'd add in the prices

strelink - I'm so sorry (perhaps you could pretend that you have one?)

DeliveryValve - I'd do my best!

I'm only asking this question as I got the impression that most people on the forum have the OM617a (turbo) and therefore a non turbo wouldn't be of interest

I have an NA OM617 that I am replacing with a turbo version, and I can still see the potential value in a rebuild thread for the NA engine. (Besides, I sort of figured I would just crate it up and stash it away, just in case I ever need it for something.) If you can combine good photos with good descriptions and technical data, then I say you should go for it.

I own both a turbo and a non-turbo (two actually, but the CD will probably be converted to a turbo).

I am content with the power I get from the non-turbo motor in my TD, but in the wagon the 500 or so extra pounds make it only acceptable in traffic around here. So when the day comes it begins to get tired, I'd like to have a reference around to follow in refreshing it.

thx

I find my 77 300d N/A does okay. Many of these older models need a serious tune up to maximise the power. I still feel that car would benifit from a slightly lower real axel ratio. It does not impact the reliability. Just would like to hear the engine turning a little slower at speed would be nice.

It may impact the fuel milage a little as well. I also have the cure for this. Driving one of my 240ds at speed seems to be far worse.

Injector condition, fuel supply pressure and timing come to mind especially. Linkage integrity is also high on the list. I have seen at least a few examples where the arm on the injection pump is not pushed to it's stop.

To repair any deficiency found is more time than money usually on these. I thought the early wagons also had a higher rear end ratio to offsett some of the additional weight as well. Also checking for dragging brakes is not a bad ideal.

I'd like to see it, I am still looking for the right CD and as said a lot will still be true for the turbo guys. Lets see it!

In particular I'd like to see an approach to measuring cylinder wear that's more technical/accurate
than "the cylinder isn't scored and looks round".

The tolerances would imply the use of a custom bore gage to "get it right". And
measuring taper in a deep hole ain't the easiest thing to do.

So, take lots of pictures, and explain your method! Cylinder fitment is key to good
power, especially on a N/A diesel.

--frankb

Telescoping bore gauge.

My personal feelings on the matter of bore measurement is that it's best left to a machine shop. Why? Well, for one thing, the telescoping bore gauges are prohibitively expensive. Second, it actually takes some practise and skill before one can get repeatable measurements with such gauges. I've tried it with borrowed bore gauges, and still can't do it right. Taking the measurement is almost an art, and if you are inexperienced, it's worth paying the machine shop to check out. Besides, if it all checks out, you can then pay them $10 a hole to hone the bores, and you'll still be money ahead versus buying a hone and trying to do it yourself.

As mentioned, telescoping bore gauges, AKA T gauge or snap gauge. Set it, pull it out and measure with a micrometer or a good set of calipers.
FWIW, the 617 isn't a deep bore. When I rebuilt my Ford 300-6 (the third or fourth one I've done) I did four measurements per bore- Two 90 degrees apart at the top just below the ridge, and another two 90 degrees apart at the bottom of the wear area. Due to wear, I had to bore it to 4.080" and use .030" oversize pistons for a Ford 360, bumping my compression to 9.8:1, but that's a whole other story. That was a 3.98" stroke vs the 3.5" stroke of the 617, with a taller deck height as well. It was a little easier due to the larger bore, but I've measured out Subaru engines with an 82mm bore vs the 90mm bore of the 617.

Four more days to vote!

I've just done an engine removal thread here:-

http://www.peachparts.com/shopforum/diesel-discussion/289886-how-i-took-out-my-1981-w123-300d-euro-non-turbo-engine.html

From this you can see how in-depth the engine rebuild thread could be. I think engine removal is pretty tedious - I don't want to bore anyone with the rebuild thread if it goes ahead!

That's an awesome engine removal thread. It is really going to help me when I swap engines in the not-to-distant future. Mucho thanks! With any luck the response to the rebuilt poll will be overwhelmingly positive, and I'll benefit from that as well.

Kurt

We have a sitting dead 80 300td that needs his heart restarted. I would really appreciate a ridiculously thorough N/A rebuild thread. You would truly be doing us a solid.

... I'm about to start pulling a dead crank from my 85 turbo motor... of course I have to clean my shop first... I AM SO SICK OF STEPPING OVER THE MOTOR...

I think it's a great idea. Please do the rebuild thread.

- Peter.

I started writing my War and Peace sized engine rebuild thread yesterday - Webmaster please buy some more disc space! Hopefully I'll finish it before Christmas...

SAweeeet!

german cylinders flying left and right...cats and dogs living together...MASS HYSTERIA