Considering that the typical 616/617 is driving around with the timing retarded 8-10 degrees, worrying about whether the timing should be set to 24.0 or 24.1 degrees is pretty absurd.

Thank you.

Drips
 

Rino...Thank you for slugging this out...You are correct....You have made me rethink this....

The problem is the technical writers are given fixed values for this adjustment from the manufacturers or sellers and they plop it down in the text no questions asked...These pumps are used on many different types of engines on all types of equipment and vehicles....probably whoever was in charge of the info when it was being published got a figure from some (technical expert) that was in charge of the equipments information...farm equip, trucks...generators....etc...

Over the years many of these fixed values have been taken for gospel truth.... when in reality it should be written as a range of drip count rather than a fixed value...most of the people that came up with these fixed numbers are probably dead by now....and these values have become sacred to whichever one some old Diesel Troll is accustomed to....makes you wonder if this is done on purpose...If you could dig these old guys up they would still scream and holler their number is correct and everybody else is wrong and are going to ruin the engines...

The precise drip count that would enable an engine to run the best is probably in that 0-30 drip rate (Rino Method) but actually would vary from engine to engine depending on age, wear and such.....(thus the reason for the dynamic test)

It really is conflicting information when one looks at the different counts from the different sources....
They should describe the process better in the manuals as to what is actually going on with the timing procedure for DIY manuals....

The different count methods are a confused imprecise jumble when looked at logically....This was your original question and I agree with you...

But like different good shrimp gumbo recipies the end results are still worth doing.... People still cannot agree on which recipie is best in fact...but they are all good...
0 to 30 drips is a big drip number difference... but very small when linked to the amount of crankshaft rotation degrees for that drip range.... which is what they are really concerned with for beginning of delivery or fuel column push...

Was there ever any more news on the millivolt method with the glowplugs? Read through 5 pages of that thread and it took me 2 hours...

millivolt
 

300sd81...that was my last timing effort on the 300d and the 240d...both peaked out at 26 degrees when checked with the overflow tube method....seems to work fine....I had a voltmeter on each plug for the test...they all seemed to track each other closely while moving the IP...

Rino... ah yes, IP timing, one of my favorite stubjects...
 

Rino - When you mentioned the above, were you talking about this Wika DIY article that is titled " How to Set IP Timing via the Drip Tube Method
on the 1982 240D (OM616) ":?
http://www.peachparts.com/Wikka/OM615OM616InjPumpTiming

Thanks " Yellit " for alerting me that this THREAD was up. I haven't watched the new stuff very close as of late!

Yes, I'm still trying to get a diesel timing light that gives the same timing results... consistently for an engine. I have two new piezoElectric pressure clamps arriving soon to see IF they will work with and improve upon the lack of consistency we were getting with our Kent-Moore J33300A "Tach-N-Time" meter. Will post any worthwhile results on this THREAD or maybe start a new THREAD depending upon what we find.
Regards,

Rhino, the drip method is basically a universal fairly easy method to put the engine and pump into time. Nowhere is it indicated that it is the best timing for any given engine at this time.
It just is not a dynamic means so does not reflect the actuality of conditions in the cylinders while running. All the factory recommended drip measures are for is to get the engine and pump start of delivery as close to the 24 degrees refference mark as possible.
That is why the dynamic milli volt method was looked at as it does accuratly reflect the hotter burn threshhold so you have a little more efficiency and a little more power to boot. Alas the stiffness of the injector tubes made this approach just about impossible. .
Yet I personally still feel it had the best accuracy to come along the pike. This is confirmed over and over again with posters stating their engines seem to like 26 degrees indicted better.
Another conformation is the milli volt method always seemed to land up at about 26 degees as well. It does reflect a slightly hotter or more efficient burn cycle than 24 degrees.
To put this in further context it all started when It was felt the milage and power of these engines was posssibly increasable to some extent. There was just too much varience between different examples of 123s milage and performance for it just to be driving habits in my opinion. Whatever drip count method is utilized by you the intent of the manufaturer is to end up at 24 degrees indicated. I would go the lesser drip rate to favour the slight advance inherent in it over the more drips per unit of time. Just better than the retardation of timing by more drips in my opinion.
Do not forget either that 24 degrees was for fuel of the cars design era. The fuels celane number and burn charactaristics have changed with time. I think as well with all the present evidence 26 degrees by drip test is well worth trying. There is a noticable difference between 24 and 26 degrees indicated.. If nothing else the milli volt method proved that.
Sam Ross and Yellit deserve a lot of credit for their combined efforts in this area to move existing knowledge forward. They did do it in my opinion.

Barry,
What is your best guess as to the difference in timing when advancing from 1 drop/sec to .05 drop/sec?

Probably virtually nothing. I think the fuel feed pressure would give far more varience. There seems to be no known standard for that. Favoring the advance side just seems to be good business for these engines on todays fuels.
As someone mentioned most these cars are running around with retarded pump timing for starters. At retarded settings there is not much apparent change in engine performance over a broad range for common sense purposes. It is only when you get close to whatever the optimum setting is that a couple of degrees seem to make a really noticable difference. Again just my opinions.

The variability of the drip method based primarily on supply pressure is one of the principal reasons why the RIV method was developed.

For the later 617's, an electronic probe is inserted into the IP and the timing can be accurately set to within 1/2 degree, independent of fuel pressure and drip counts.

The entire discussion of drops per second is somewhat over the top when the variability of fuel pressure during the process is ignored. The drip method is a compromise, at best, and the accuracy is not better than +/- 1.5 degrees or so.

That's the truth, however inconvenient.

Reminds me of the old saying, "Measure it with a micrometer, mark it with a grease pencil, then chop it with an axe."

Darn Rino, you've been arguing this to death here and at the other place. Why don't you try the search function. Try searching on the "Bubble Method" and "Timing Tool" and "RIV method".

You are very welcome... I am glad to have finally found someone who understood what I was talking about...

I don't think "0" does it. Let's say, the .5-30 drip rate (from 2 drops/sec to 1 drop/30 secs) is possibly more appropriate...

Thank you. That was PRECISELY my point.

Agreed. But remember, my question was from the beginning a conceptual one challenging any strict adherence to any specific method as... well, questionable...

Yes, that's the one I had in mind...

Rino, pronounced as Reno, NV... :)

So, you are basically suggesting to set it at 26 degrees using the 1 drop/20 secs drip rate, correct?

Compared to the 24 degree timing, what are the benefits and disadvantages?

I suppose, more power and better fuel economy when set at 26. But will the engine start as readily, especially when cold.

Well, good to know... Many thanks to Sam Ross and Yellit, then.