Whilst browsing various forums, I came across a guy (OM.616 on another Forum) who has tuned the N/A 616 and 617 engines, and has found good gains without excess smoke...

So, decided to give it a go...

Took my spare pump, and altered the 2F set-screw Exactly 1 turn and also the coarse-Idle, 2B exactly the same amount...

Initial tests here in W/S indicate no excess smoke when throttle fully cranked open--(This wagon never made any anyway, suspect underfuelling as it was....)

--Looking forward to drive home from work today.....

Things to keep in mind when altering the IP---

When the coarse-idle is altered, it affects the position of the main throttle lever--Quite Considerably! 1 turn of the set-screw 2b alters the position by around 1/4 of an inch, and you Have to re-set throttle-linkages because of this....

Let me know how everything turns out with the tunning.

Well, so far I am quite happy with the adjustments, A definate improvement.

There is a small apparent extra power when pulling away from standstill--Not huge but an improvement.

As revs build the power is definately better. As it was still light at the start of my jeorney home, I observed for smoke, but could see very little when pulling away or at moderate to higher revs.

I have a 50 mile trip home, around 25 miles on the motorway (Freeway), which has some hills. There is one long hill particularly where this car would usually start to drop speed to around 75 (Allegedly!),--similar to my old 190D,--That would drop to about 80...

Today on this hill, I mashed the gas, and it was still pulling at 85!--I limited the run to around 30 seconds, I have no EGR guage at the mo, and the engine-temp just started to creep up a milimeter or so, from its normal 80 deg.C dead...

As I approached home, I have to go through the city and its now pretty dark. I carefully observed for smoke in headlights while pulling away from lights etc, and found very little, even when half throttle and approaching WOT. On the fairly steep hill local to me here, I found that at low to medium revs WOT, there was just a small amount of smoke, but as revs built to near the auto trans. change-point, I started to get more, Not Huge smoke but more, Gear changed, and smoke went....

--Guess this proves that the N/A engine doesnt 'breathe' too well at high revs--Not surprising really!

--Summit I will do as in its current adjustment setting, is I'll take it down to a friend's garage and borrow his MOT 'Smoke-Meter' Its last MOT Test registered 1.58, only a few months ago (Limit on test is 2.5 for a N/A engine) on opacity test running straight Dino D2.

Be interesting to see with these adjustments and running 100% BioDiesel what the opacity readings are....

When re-installing the I.P. i set timing perhaps a little advanced at 29-30 degrees, It has just a 'nice' diesel-combustion noise, similar to when it was at 24 degrees on D2, I may drop it back a couple of degrees to around 27-28....

I'll leave the I.P. as-is for a week or two, and maybe have another little play, although I think much more would give more smoke, but so far, pretty happy....

(02-25-2010 01:25 PM)OM616 Wrote:  I say "may" because I am not sure if when, ( on an M pump), after a full load adjustment, does the resulting throttle lever position change, alter the Min Throttle Spring Tension.

If it increases it, you will see an increase in throttle response, and fueling at any given throttle position at a given RPM, but if the Idle adjustment was actually the MIN Throttle Spring Tension adjustment, (restoring the tension after the full load adjustment), then you will be back to stock response.

It sounds like, (smoke wise), you are at a good full load position, but knowing what the EGTs are would be good.

Just re-read your post and can say that Coarse Idle adj, '2B' set-screw Appears only to affect the position of the throttle shaft, ie, a 'Throttle-Stop' screw, like you would find on a Carburettor....

--Whether this position affects the other related 'springing' of the Governor, I dont know yet, Guess it must do but have no idea what exactly. I'll see what I can dig up on the 'M' type Governor....

---

http://www.freepatentsonline.com/4735182.pdf

The above patent Appears to be for the RSF Governor used on the 'M' type...

I'll hopefully have some time tomorrow to try and understand what its all on about!

(02-25-2010 01:25 PM)OM616 Wrote:  If that is all you altered, then it should not put out any more fuel at a given throttle setting than stock because you did not alter the torque control, which sets and positions the fueling curve in regards to the throttle and engine RPM.

Thats not how it works. Torque control is responsible for reducing fuel as the RPM rises to match the reduced VE of the engine. Adjusting it will not increase maximum fuel, it will not take away as much.

Hi Lance, How you doing...?

I have read your experiments and findings using a M-Type for your Turbo motor, What would you recommend as an additional adjustment to my current set-up, say--The T.C.? and by how much...

OM.616...

Hopefully today I'll get an hour or so to fully go through that patent on the RSF and with any luck, my tiny brain will see exactly whats happening with the TC side of things. All I defo know, is that its a Two-Speed governor,--With this additional Torque-Control.

Another thing worth remembering, is its not only V.E. of the engine itself that needs accomodating in the Governor for...
For a given control-rod position, a Plunger-pump will give an Increasing fuel delivery with rising pump-shaft speed--A Rising Rate fuel delivery...
--Maybe its this fact that causes the 'delicate' nature of the TC adjustment with regards to 'non return to idle/runaway' issues when its altered....

(02-25-2010 09:20 PM)OM616 Wrote:  Where did I say that adjusting the Torque Control will increase the MAX FUEL??

It was implied by your wording.

Quote:If that is all you altered, then it should not put out any more fuel at a given throttle setting than stock because you did not alter the torque control, which sets and positions the fueling curve in regards to the throttle and engine RPM.

The TC capsule does not care what the max load setting is. Its job is to progressively reduce fuel at max throttle with rising RPM (from the increasing flyweight pressure) before the main governor spring cuts in to limit RPM.

Quote:With a stiffer Torque Control Spring setting, the Fly Weights will not back off the fuel as fast which will increase bottom end and mid-range performance.

As well as making the engine not return to idle.

(02-26-2010 02:40 AM)Alastair E Wrote:  I have read your experiments and findings using a M-Type for your Turbo motor, What would you recommend as an additional adjustment to my current set-up, say--The T.C.? and by how much.

Since you don't have a turbo to make up for the poor high-RPM VE, I wouldn't adjust the TC more than 1/8th turn, if at all. 1 turn for the max load and coarse idle is good, but you really need a pyrometer before you do anything else.

Yup, I agree....

Really need to get a Pyro on there, just to be sure I'm not overstressing things as they are, let alone any more adjustments....
--Especially if I did add a turbo--With VERY LOW boost....

--Ah, well.....Things to think and dream about.....

(You guys with the Turbo motor dont know how lucky you are!......We never got 'em here in UK, and was Nowt to do with the old 'Steering-Box in the way' myth, It was an 'Exec. decision' at M.B.....)

(02-26-2010 08:32 AM)Alastair E Wrote:  You guys with the Turbo motor dont know how lucky you are!......We never got 'em here in UK, and was Nowt to do with the old 'Steering-Box in the way' myth, It was an 'Exec. decision' at M.B.....

the real reason that you guys didn't get the turbos is that MB said its too dangerous driving turbos on the other side

(just joking)

There are 6mm elements and different delivery valves offered as "MB power kit" for M-IPs on n/a engines (W124 but might work also on 123).

Tom

Wot on earth happened in this thread.....??

Where are the various Posts by 'OM.616' gone...?--He was the guy as far as I know, who first started adjusting up the N/A engines, and brought it out in forums....

Did he himself delete them...? Or did someone take exception to something he said....
--From what I recall, There was nothing in any Post that could have caused offence....

Worth remembering, Excessive 'Censorship' is the Death of Democracy--And Forums!

(02-27-2010 03:17 PM)Alastair E Wrote:  Did he himself delete them...? Or did someone take exception to something he said.

He removed his own posts.

   

(02-27-2010 06:49 PM)ForcedInduction Wrote:  

(02-27-2010 03:17 PM)Alastair E Wrote:  Did he himself delete them...? Or did someone take exception to something he said.

He removed his own posts.

That is only two, tell them what happened to the third.

Many regrets for the pissing contest, not my proudest moment. I am too old for this.

Hmm, What DID happen to that third post...?

--Right or wrong, It did have interesting info...

Anyway, to update, I have done no more adjustments, just driven and observed...

Noticed the smoke levels seem Less than I first described...I'm thinking that as I have been just cruising round back and forth to work etc, I had built up some crud etc in the exhaust/engine, and i know the guy I bought the car from lived in centre of London--LOTS of stop-starts in that nightmare rolling road block!

Gave it a bit of 'Italian Tune-Up, a fair amount of crud, coming out in bursts that eventually cleared after around 30-40 seconds...

Much cleaner exhaust since, Nothing visible in daylight at all....

(02-28-2010 05:57 AM)Alastair E Wrote:  Hmm, What DID happen to that third post...?

The third post? Oh, you mean the one liner that had no contributing factor to the thread other than taking a swipe at me?
Have another tantrum and remove all the posts you like 616, it shows great maturity.

Alastair,

Just a thought:
I am a turbo man, but a friend of mine with his n/a is also interested in swapping 6 mm elements together with the DVs.
Maybe I can get an IP (5 cyl. M n/a) done with the a.m.
Then it might be possible to ship the IP to Wales for testing. In case you like it you pay or you send it back at your cost.

Tom

The NA might have some economy and power benefits from quicker injection duration, but I doubt it would be enough to overcome the cost of whats basically a pump rebuild. Especially only going up 0.5mm, wouldn't the 7.5mm make more sense for your friend?

there is an after market "kit" consisting of 6mm M elements and "suitable" DVs.
With the 7.5mm I fear the governor range has to be limited too much, but who knows.
On the other hand the more I think about it the more I like the idea of doing the 7.5mm thing for reference.
I'll talk to my friend...
Thanks for the hint.

Tom

(02-28-2010 07:40 AM)tomnik Wrote:  Alastair,

Just a thought:
I am a turbo man, but a friend of mine with his n/a is also interested in swapping 6 mm elements together with the DVs.
Maybe I can get an IP (5 cyl. M n/a) done with the a.m.
Then it might be possible to ship the IP to Wales for testing. In case you like it you pay or you send it back at your cost.

Tom

Hi Tom,

--Thats a very kind offer! It would be interesting to see the effects of the shorter duration injection phase...

P.M. me the costs, and maybe we can do something...(Bit broke at the mo, just paid a shed-load for this W123 wagon!)

(I have a theory, that the faster rate of injection Could well offset somewhat the extra heat that could otherwise be generated in EGT's, over a relatively long injection phase of the same quantity....)

Be a good start for my Turbo-franken-toasted-617/N.A!--Thankfully I do have a spare re-built 617 N/A....

Its an 'M-Type' fitted to a N/A OM.617 -just for reference, When are you next in Wales,--Do you still come over with your business?...(Or is it the factory you visited here due for closure...You know the one I'm sure, Owned by a big German Co....)

Don't worry about costs, you test it first and decide to pay or to send it back.
Now this makes sense cause my friend is asking for the same for his 617 n/a.
So I will do one IP and let you guys test it.
Give me some time to find an IP and get the swap done.

The business is increasing, besides Baglan I also come to Devizes.

Tom

(02-28-2010 03:19 PM)tomnik Wrote:  Don't worry about costs, you test it first and decide to pay or to send it back.
Now this makes sense cause my friend is asking for the same for his 617 n/a.
So I will do one IP and let you guys test it.
Give me some time to find an IP and get the swap done.

The business is increasing, besides Baglan I also come to Devizes.

Tom

Hi Tom,
I have two 'spare' 'M-Types' from 617 that have not been altered as far as I know but stood for some time, one is still on old engine...
--They were working well before being laid-up

I also have a 'M-Type' from a 4 pot OM.616, but have no idea if its any use,--Bought it well cheap on fleagay--You're welcome to that if its any use to you....

--Let me know if they are any help to you...I am really interested now in the larger element/Rate Of Delivery ideas...

I drive past Baglan Every Day, on my way to Caerphilly near Cardiff from Swansea--In my 1985 W123 Wagon!

Devizes is down Westcountry from me, but Not THAT far over the bridge, Sure we can do something!...


Just had a thought...

The N/A Pre-Chambers are different to the Turbo Motor. The hole geometry and size is different. Larger on the Turbo motor. I wonder whether there would be an improvement in either economy or power by changing to the Turbo Pre-Chambers...?

n/a and turbo PCs are not interchangeable.
The outer diameter of the turbo's is bigger.
Let's stay on the topic and do one step after the other (at least I have to do this to not loosing the focus).

For the IPs I'll check over here first (in my friend's garage), thanks.

Tom

(02-28-2010 04:05 PM)tomnik Wrote:  n/a and turbo PCs are not interchangeable.
The outer diameter of the turbo's is bigger.
Let's stay on the topic and do one step after the other (at least I have to do this to not loosing the focus).

For the IPs I'll check over here first (in my friend's garage), thanks.

Tom

Yup, quite right....

I was getting a little carried away....

I have these pumps here if you need them...

Hey, Tom.....!

Any news on the pump for your friend...?

Did you manage to talk to your guy and find what options would be best for the 'M-Type'? Let me know if you need a spare 'M-Type' or two....
--Thanks....

I get the IP on Saturday!
My friend is pushing me now.

Tom

(03-09-2010 03:41 PM)Alastair E Wrote:  Hey, Tom.....!

Any news on the pump for your friend...?

Did you manage to talk to your guy and find what options would be best for the 'M-Type'? Let me know if you need a spare 'M-Type' or two....
--Thanks....

Good luck with it Tom, Hope your friend likes the new pump!