Why did MB never run balancing shafts on the M111?

[Pagz]

Not sure if this is the correct place to post this but they do effect perfomance.

I have the M111 engine with a turbo setup,individually balanced flywheel, crank,rods,pistons and crank pully...however it suffers from the inherrent 4 cylinder second order vibration...

This means that things need to be well bolted down or need to be well isolated from the vibration.
It once ran a stainless equal length manifold which had alot of flex,this caused a harmonic resonance between the turbo and engine at certain rpm,this has since been replaced with a thick wall steam pipe manifold.
the part that continually suffers is the turbine heat sheild,the stainless arms fracture from heat+vibration.
I also run the V8 engine mounts which possibly adds to the equation.

Does anyone know if the newer 4 cylinder MB petrol engines run balance shafts?...i know the new diesels do!
Did any of the late M111's run balance shafts?

Cheers,
Paul

[whipplem104]

No, the m111 never did come with balance shafts. I think that the m271 came with them but I am not sure. The m112 v6 has one.
I have to say though that I never really thought it needed it and a lot of mitsubishi guys and I assume others take them out of their engines. If you are getting a lot of harmonic then it may be from reducing the rotating mass. But even then I would not think that it should be breaking stuff.

[JayRash]

Was the original engine, before al the rebuild, suffering such vibrations? I mean i really can't see Mercedes screwing up an engine this bad, they might screw up cabin quality or some electronics but i am yet to see a messed up engine design.
I have driven several cars with the M111, and true they aren’t the sweetest of the 4 bangers around , but they are far from what you have described.

IMHO, i think the rebuild hasn't gone as planned,

[c280nz]

u have pritty much built a race car paul! smoothness goes out the window at ur level
haha but just to piss you off il add that you should have got the flywheel and crank balanced as one, whip it out and do that

[Pagz]

Hmmm so the M111's never came with them,what about the 190e engines,surely the larger displacment 4's and cosworth would have?

I thought MB would have produced an ultra smooth engine too...but from what i read the increase vibration is all got to do with rod length on the 4's...something that usually increases with displacment.
So one would assume the 1.8,2 and 2.2 are smoother than the 2.3

The reason why the M111 literally doesnt shake the car to bits is because its mounted on extemely soft engine mounts,next time you see one try rock it!,as long as the mounts havnet compacted you will be able to shift it 10 - 15mm with 1 hand...my oe clutch setup also wieghed 22kg's.

Vibration has followed me through the build like this:

1.Original unopened engine + stainless manifold + N/A belt configuration(smaller crank pully from C230 M111) + stock oe everything else.
= very noticable vibration 2000 - 3000rpm


2.Rebuilt engine with Light wieght JE pistons + full balance(flywheel and C230 pully on crank) + Thick wall steam pipe manifold.
= alot less vibration but still noticable 2000 - 3000rpm
heatshield never broke.


3.rebuilt again with oe oversized pistons(dont ask why) + custom flywheel/clutch@ 17kg + balanced flywheel but not on crank as didnt need to + V8 engine mounts + evrything else the same
= more vibration than before 2000 - 3000rpm slight increase in chassis vibration but not significant.
Heat shield keeps breaking,manifold bolts slowly come loose.

My own conclusion is that this engine does make good torque for its displacment which usually means longer rods and more vibration so they say,why they didnt run balance shafts is more than likley a cost/complexity issue...the cheaper fix was possibly a very heavy flywheel and soft mounts...

Iv spoken to a guy who ran the stock engine but with an alloy flyweel some years ago...it suffered from the same vibration.

What is annoying is that a 2.4 honda with almost solid engine mounts is so much smoother.

Logan - howed you end up here!,i switched forums to get away from your picky comments =P JKS hehe

[Pagz]

aha,from MB...



"From August 2002 the C-Class will be even more attractive with newly developed four-cylinder engines and a number of value-enhancing modifications. The advanced power units feature the sophisticated TWINPULSE system, which is exclusive to Mercedes-Benz and combines different technologies such as super-charging, intercooling, variably adjustable camshafts, four-valve technology, Lanchester balancer and adaptive drive dynamics. This guarantees a low fuel consumption with a great deal of driving pleasure, smooth running and therefore even more typical Mercedes long-distance comfort.
Moreover, the new Mercedes four-cylinder engines already comply with the strict EU4 exhaust emission limits for the year 2005."


Lanchester balancer is the item i wish i had =)

[c280nz]

try norlock washers for the manifold, there two washers joined together with little shark teeth, pritty good, i use them.

ur unlucky with all this vibration! i run the lightweight flywheel and stainless manifold and dont really get any vibration, but do get a resonance in 5th if i labour it (under 2k), so no real issue.
theres some good guys who know there stuff over on this forum paul.

what about going back to soft engine mounts and using one of those little engine dampners attached to the top of the engine (basically a little shock absorber)

[23K]

hmmm yeh have seen those at the hardware supplier!,might give them a go!.

The vibration is a pain,its not very noticable inside the cab...but i know its happeneing because when the heat shield breaks it rattles at a very high frequency.
The initial plan was to run the original mounts and use a dampner as you mentioned but i think the V8 mounts will do just fine.

Your 6 should be a lot smoother...as your firing pulses overlap,where as mine finish before another combustion starts,this joins forces with the awsome frequency(2xrpm) of my two sets of pistons traveling at different rates.

Next time: 2001 SLK320 kompressor engine with 6 speed manual from the N/A model^^
has a 9.1 cr too.=)...




Edit: just realised i have 2 accounts on here=)

[c280nz]

Originally Posted by 23K

Edit: just realised i have 2 accounts on here=)

typical....

how is your car going at the moment?

you could make a heat sheild out of this heat resistant alloy wavy stuff that i used, i cant remember the name but it is sort of like couragated cardboard but i think it has some time of ceramic or aspestos stuff in the middle, its easy to bend and use. i think its for aircraft, may be an option

[Pagz]

Originally Posted by c280nz

typical....

how is your car going at the moment?

you could make a heat sheild out of this heat resistant alloy wavy stuff that i used, i cant remember the name but it is sort of like couragated cardboard but i think it has some time of ceramic or aspestos stuff in the middle, its easy to bend and use. i think its for aircraft, may be an option

Mmm yeh know the stuff,its commonly used on firwalls etc?
We did strengthen two of the arms,but the 3rd has snapped now,i think after we fix that it should be ok-ish,its so wierd how they keep snapping it never snapped on the first setup,and this heat sheild is new again maybe the stainless was a lessor quality?...pretty sure its not though.

Another theory about the whole vibration saga is the turbo,being how it is it sits beside the engine supported by pipes,any flex results in damaging frequency at some stage in the rpm,the long exhaust downpipe on my setup is no longer supported beside the bell housing like the oe manifold was as theres too much expansion...however we did install another exhaust hanger at the front of the driveshaft...this would add to cabin noise alittle i think.

the manifold is very very strong but I could try bracing the turbo from the rocker cover but im not sure that will help at all and im not sure if the rocker cover will handle the expansion...dont want to be buying a 3rd one now....lol.
other option is from the head but theres little room to work with.

And as for how its running....well.....:huge sigh:
I got he g/f to take it for a gun down the road last weekend in tauranga was an interesting experiance for her,she stalled twice,but once she got going it was ok,bit harsh on the changes....but then she paniced when we came to a corner...about then i decided that was enough for one day,lol
she agreed lol

Anyways... sure enough its blowing a light blue smoke,then black/grey at rev limit

But its different from before...no longer does it blow smoke under light load high vaccum conditions-where you would give it some and it would burn off then stop...now its light blue through the most of the rev range under load with no sign of it under normal driving.
last time i checked the spark plugs there was no oil present in the chamber like with the JE pistons.
valve seals were replaced for a second time as precaution.

So i suspect the seals on the turbo are the cause...having been chewing on metal bits from the filter wouldnt help balancing + i attacked it with a file to make the compressor damage smoother...that combined with the harshness of the engine could possibly lead to the failure.


Apart from the smoke it needs a minor map at very light load,most noticable at 100 - 110km/h it hesitates alittle now and then.

Apart from those small issues it runs very very well and is very hard to keep under the speed limit...i accellerated out of a 70 zone(coned off as a bump in the road on state highway 1) in the middle of the nowhere a few weeks back,went upto 115,noticed was a tad over so straight away backed off to 105,30 seconds later champaign corrolla gave me one for $80...dang had been being so careful too.(at 90 points atm not good)...which is a bit gutting as i prefer to think i dont drive like an ass that often.


Hows your engine running now havent heard much in a while???

[wbain5280]

Is the harmonic balancer still mounted on the crank?

BTW, Mitsu invented balance shafts, so MB sould have to pay a royalty.

[c280nz]

90 demerit's? its called a v1, get one already.
i drive like an ******* most of the time and only have 30,
i got a ticket in auckland when i was there tho for not indicating while changing lanes, typical i said, but i didnt make a big seen

that sucks about burning oil, the answer to that is dont follow your car and watch and youl never know! im not sure if my one is but it doesnt use any on the dipstick and i cant see smoke in the rear view, apart from this one time when i was parked up at the whalf in aucks haha jks

cars goin alright tho, but like you its always a work in progress, still cant get enough fuel, i have to wire in the injectors individually to the greddy for better control and get a map sensor, this is the next project,
but when its going good she hauls pritty well, i ment to do the wiring this week at night, but its already at thursday doh, and i goin out on my mx bike all weekend, so maaaayyyyb next week,

[Pagz]

Originally Posted by wbain5280

Is the harmonic balancer still mounted on the crank?

BTW, Mitsu invented balance shafts, so MB sould have to pay a royalty.

Yep i still run the harmonic dampener pully!.
however i dont run the 22kg dual mass,instead i run a 17kg single mass.

Very interesting about the balance shafts from mitsubishi i did read they were one of the first to use them but didnt realise they invented it?...if this is true then cost was the likely reason MB didnt run shafts...i cant see any other reason they wouldnt as the hp cost is minimal on a street car.
Makes me want to transplant to the newer 4 cylinder.

[Pagz]

Originally Posted by c280nz

90 demerit's? its called a v1, get one already.
i drive like an ******* most of the time and only have 30,
i got a ticket in auckland when i was there tho for not indicating while changing lanes, typical i said, but i didnt make a big seen

that sucks about burning oil, the answer to that is dont follow your car and watch and youl never know! im not sure if my one is but it doesnt use any on the dipstick and i cant see smoke in the rear view, apart from this one time when i was parked up at the whalf in aucks haha jks

cars goin alright tho, but like you its always a work in progress, still cant get enough fuel, i have to wire in the injectors individually to the greddy for better control and get a map sensor, this is the next project,
but when its going good she hauls pritty well, i ment to do the wiring this week at night, but its already at thursday doh, and i goin out on my mx bike all weekend, so maaaayyyyb next week,

*****^^ gunna have to agree with you on that,i actually forgot totally about getting one!,will check TM later.
There are alot on the road atm,everywhere i go theres people pulled over, guess its make a profit or take a 9 day fortnight^^.

Hahaha i tried hard not to know if there was blue....what got me was the g/f couldnt tell what was blue or black...lol...damn so i just had to find out^^

Sounds good!,just dont blow it up this time =P
Any plans to get a bigger pump?
With your on road tuning what sort of wot ratio are you tuning too?
weather looks good for this weekend too,try not to break yourself!

[Spetz]

Sorry to bring an old thread up.
But does this mean that the vibrations I am noticing in my M111.960 powered car are normal and unavoidable?

It idles very smoothly. Has some humming vibrations at 2,500rpm, and then feel some vibrations from 4,000rpm onwards.
Engine and transmission mounts have a couple hundred mile on them so far.