Lombardini Diesel

[daveNZ]

thanks for that. By "register" I assume you are referring to the common link bar that advances fuel flow to all injectors. A sliding plate seems to be a crude adjustment method!
The other adjustment is the screw on the end of each injector for the static injector advance. I assume you are talking about the first one.
(There is also a pressure test for each injector adjusted with shims)
My engine only vibrates between 750 and 950rpm, and is perfect above 950rpm, from what you know do you think could either of those adjustments be out enough to affect idling, but ok at higher rpm?
Also, sometimes I find the idling is OK? but I can't pin it down to whether it is cold/hot/??

[bikesherpa]

Hi Dave,

sorry if I was not very clear.
You have to rotate the plate of the pump in order to increase/decrease pressure. See picture from the service manual.



Once you have found the right setting, fix the screws.

You'd need this equipment to equalize the pumps

[daveNZ]

Thanks for your reply, but we must have different models. Mine is FOCS series 1404M (fully overhead control system) and the pump/injector units are all under the rocker cover, injectors are all advanced by one long bar. Each injectors flow can be changed by moving its link to this bar.
Thanks for your notes but although the principles apply the mechanism is different.


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[magomerlino]

The lom ldw 1003m and the 1404 are the same series dave. I have everything under the cover as well. jim

[magomerlino]

dave, I have the lombardini man here. found one of the none return valves has no ball in it! disintigrated after about 60 hours running.
However it hasn't sorted the vibration. i have tried your mmethod of slowing to the 600's and i can get in and out of gear with minimum vibration. We get bad vibes though as we go up through the 800's.
They say I need stiffer mountings and engine is vibrating with soft mounts so much that it is affecting the governer weights. Nonesense in my view as we have no probs at lower revs. Stronger mounts will mean a shaking boat instead of a shaking engine. Could I ask what shore hardness your mounts are. lombardini supply shore 60's which is way too high for a lightweight engine like this. jim

[Polux]

"They say I need stiffer mountings and engine is vibrating with soft mounts so much that it is affecting the governer weights. Nonesense in my view as we have no probs at lower revs. Stronger mounts will mean a shaking boat instead of a shaking engine. Could I ask what shore hardness your mounts are. lombardini supply shore 60's which is way too high for a lightweight engine like this."

If they supply stronger mounts for that engine and the Lombardini man says you have to mount stiffer ones maybe he is right.

I have a Lombardini on my boat and it works normally.

[daveNZ]

Jim, interesting, so you were right about the non-return valve which is great.
The product manager in NZ recommends a mount from Trelleborg called Cushy Float.there are quite a few specs but I'm not sure how to interpret them.
I know they have supplied other Lombardini users with different (Ii.e. latest recommended) mounts years after their original purchase. Not sure if that helps.
I tend to agree that a new mount might disguise the issue, but not fix it. And I don't feel that vibration is a result of fluctuating input from the governor.



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[daveNZ]

Sorry I have no idea what my mounts are. Nor does the product manager recognise them from photographs!


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[magomerlino]

After changing the faulty none return valve and slowing idle to 650. I can now get in an out of gear without bad vibration on shore 45 mounts. However as you say dave, you have to go straight up to over 1000 rpm from there or she shakes. This is a very positive improvement on idling at 1100 and crashing into gear.
what do you all think about a fitting a head brace on these engines? We have four lower engine mountings of course, but the higher part of the engine has no support so shakes around. lots of cars have braces up top. Why not marine engines.

[daveNZ]

Any progress with the slow idle vibrations Jim. I guess it is winter in the north.
I've just had another summer juggling throttle and gear shift and it drives me crazy. Also stalled the engine a few times due to using low idle. Not good when getting out of our marina. Sometimes it is better than others but I can't get a consistent acceptable low idle below 1000rpm in neutral. When I shift in to gear it actually drops to about 950 which then shakes the boat. The natural resonance of the boat at these revs is a factor, and maybe super flexible engine mounts is one thing to try?



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[magomerlino]

Hey Dave. Opportune as we launched yesterday. Havent been out for a good test as yet, but I have fitted larger footprint mountings. cuchyfloat 185 mm footprint rather than the 100mm ones. I am trying your low rpm idea and so far (on the pontoon) i am going in and out of gear ok at about 700rpm. The shakes start above that at around 850 but as we are in gear by then it isnt so bad. It seems to me that if you engage gear at 850 where the engine is shaking. The governer is shaken so badly that the whole unit goes into spasm and cannot recover. So go into gear at a different rpm. As you go through the bad patch she shakes a bit but no spasm.
Lombardini came back and fitted shore 55 mounts but although this solved the shaking engine problem, it shook the boat to pieces of course. I will not get any more help from lombardini. They have washed there hands of the affair. saying" all vessels are different and we cannot build an engine to suit all of them" Useless Bas****s
I will get back when I have managed to run them a little more.
I DO NOT think super flexy mounts will work. Been down that road and they just allow huge movement so shaft hits the stern tube when she vibrates. Then the mounts snap off. ( height adjusters) cheers, jim

[daveNZ]

Glad I wrote then, got a laugh from your comments re Lombardini people. The cuchy floats sound like the ones I was recommended so will be interested to hear how they go. Your engine behaviour sounds exactly like mine. Ok at 700 and 1000 but not in between. My 33' launch has zero rudder effect unless moving, and I need to reverse then do a 5 point turn, going180 degrees to starboard to get headed out of our berth, so repetitive gear shifting and bursts of throttle to kick the stern around is really a two lever juggling act. (Separate gear and throttle).
I would love to be able to idle at 900 or so without the door shaking performance.
There are several other boats like mine with the same engine in NZ so I aim to see if I can get aboard some to compare. We do have a thrust bearing and then a drive shaft to the engine with flexible joints, so engine alignment is not critical, and no issues with shaking the prop shaft.


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[daveNZ]

Jim, any improvement with your Lombardini and shaking at the 800-1000 rpm range?
It is winter here so little boating but my engine is exactly the same. Another thread discusses a slightly different model of Lombardini and suggests increasing the valve clearances a little, to delay the exhaust valve opening. I'm reluctant to experiment as my engine runs so well otherwise. Cheers, Dave.


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[daveNZ]

In case anyone is still following this thread.
I finally replaced Mackay MD200 mounts (stiff with almost no rubber) with Trelleborg Cushfloat 17-1600-45 (noticeably softer) and the change is amazing.
The 'shudder' that happened between 800-1000 rpm has basically 'gone' completely. I can't believe the difference. Whereas doors would clatter, they do not make a sound at all !! Have not tried at sea yet.

However, shifting into forward, even at very low revs, is now 'sometimes' a bit violent, whereas it was previously almost undetectable. Is this just a fact of life with soft mounts?

The whole boat seems quieter too. Should be much nicer idling around before and after anchoring.

[daveNZ]

This hard sounding engagement of forward is still a problem. Sounds like a big crunch at any revs, from neutral to forward. No issue going in to reverse.
One engineer feels the mounts are now too soft for my installation. They are absolutely correct for the engine weight, according to the graphs, but, I also have no forward thrust to the engine, on account of two flexible Centaflex ‘size 16’ couplings and associated thrust bearing and 2 metre drive shaft (forward of the thrust bearing).
So prop/prop shaft (shaft seal)/thrust bearing/flexible coupling/2 M steel shaft/flexible coupling/transmission. The change in angles over the couplings is within the 2 degrees allowed. I may try to make it as close to zero as I can.
Note there are no other supporting bearings for the steel shaft.
In my mind it may be the new mounts, or perhaps a damaged or failing drive plate in the TMC 60 mechanical transmission. I believe these are pretty durable but I know nothing else about them. I need to change the rear seal so may take it out and get it checked anyway??

Anyone have an opinion?