Fitting M103 3 litre into W201 fitted with M103 2.6litre

Charles Morgan

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I met a very nice chap at Prescott hill-climb yesterday with an immaculate W201 2.6 litre 4 speed auto. He has a perfect 3 litre engine he wants to fit to give the car a bit more punch (it did exceptionally well on the hill-climb driving school).

He thinks it is a straight swap, I identified ignition, fuelling (pump etc) and rad as possible issues.

Any others and has anyone done such a swap (I'm aware of the M104 swap Brett did with Carat 3.6).

Debating the merits is another discussion, just interested in the technical bits so I can pass it on.
 
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bolide

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It'd be interesting to know if the difference is in the bore or the stroke. Or, knowing how Mercedes like to complicate things, maybe both?

If they differ in stroke then the 3.0 won't be as happy to rev as the old engine. If the difference is in bore then I'd jump on it

Single cam engine so a hotter cam won't cost the earth
Mercedes 2,6 - 3,0 6-Zyl. 12V (M 103) / Sportnockenwelle - dbilas dynamic

Lightened flywheel would be on my list as well

I'm under a life ban on suggesting Triple Webers so forget I even mentioned them...

Nick Froome
 
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Charles Morgan

Charles Morgan

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Same stroke, bigger bores on the 3 litre - 82.9 vs 88.5.

Same diff ratio, so good so far!
 

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It should basically be the same process as I did when swapping my M102 1.8 for the M102 2.3 , pretty painless and straightforward .

All the same , take the ECU's from the donor car and plug them in , although they may well be the same .

I'd also consider front brakes , possibly looking at items from 190 16V models , or from a 300E .

The 300-24V version of the M104 is also a straightforward swap , giving a 231bhp 190 , plenty of people over on the Mercedes-190.co.uk forum have done it , all the info is over there .

http://mercedes-190.co.uk

If going seriously into hill climbing ( not the tarmac variety , like Doune or Bo'ness ? ) , then I might think of things like fitting a metal sump guard or suspension mods to increase ground clearance ( as with W124 , these items were probably part of the specification for other markets , such as India or the African continent ) .
 
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Charles Morgan

Charles Morgan

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Apart from the fuelling ECU what other ones are we talking about?
 

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There's the EZL for the ignition , not sure what else either
 

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Mike at MB Medway is in the process of fitting a 5.0 litre engine from an E Class into a W201 190. Can talk to him or put you in touch if that helps at all?

Mike
 
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Charles Morgan

Charles Morgan

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Not sure that is of much use given that it is a later engine, but thanks for the offer.
 

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Rob at three pointed parts bought an old scrap 300te and put the engine straight into a 190 2.6, it took him less than a day iirc, so I suspect it was very straightforward
 

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There is a guy called Shane (aka Bigger Perm Custom) based in Swansea that did the M104 swap very recently, may be worth giving him a shout

 

bolide

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The beauty of the 2.6->3.0 swop is that it's simple

Nick Froome
 

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Same stroke, bigger bores on the 3 litre - 82.9 vs 88.5.

Same diff ratio, so good so far!

According to James Taylor the 2.6 M103 had water passages between the cylinders whereas the M103 3.0 had siamesed bores. This is possibly why AMG employed bored out 2.6 blocks for their larger capacity engines rather than the 3.0 litre blocks. Mind you not all 2.6 blocks could be bored out! There are also later stories of using the longer throw crank from the contemporary 6 cylinder 3.5L OM603 diesel engine to increase stroke with suitable pistons on both M103 and M104 engines
 

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There is a guy called Shane (aka Bigger Perm Custom) based in Swansea that did the M104 swap very recently, may be worth giving him a shout


That is either a 280 or 320 , which has completely different ignition and injection systems , so a more complex swap , whereas the M103 3.0 and M104 3.0 24V both retain the same ignition ( with distributor ) and injection systems so little or no changes to the car's wiring or even exhaust systems .
 
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Charles Morgan

Charles Morgan

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Thanks for all the help, I've passed on what I have learned to Julian and hope to hear when (if) he does it.

A follow up question - how easy would it be to fit a 3litre M103 to a four cylinder 190E?
 

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https://www.mbclub.co.uk/forums/engine/208547-m104-300-24-w201-conversion.html

Possible but obviously more "ancilliary" problems ECU etc already mentioned. Think it fits but the extra length of a 6 cylinder over a 4 is manifest at the front end rather than the bulkhead end which entailed detailed changes to the front slam panel , radiator/mounts and maybe front roll bar/mounts? over the 4 cylinder model - nothing too drastic but all adds up. CARAT 3.6 has all the answers.
 
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Charles Morgan

Charles Morgan

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Quickie question, my navigation skills are proving less than optimal on the EPC - does anyone with a better idea of where to find the ECU and the EZL part number have those to hand, or can point me in the right direction. I don't like Ebay as a source as too often the parts are incorrectly labelled.

Thomas (not Julian, no idea how I got that in my mind) just asked.
 

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Thanks for all the help, I've passed on what I have learned to Julian and hope to hear when (if) he does it.

A follow up question - how easy would it be to fit a 3litre M103 to a four cylinder 190E?

Much easier to start with a 2.6 : the slam panel and radiator position has to be changed - 4 cyl cars have a one piece slam panel which has to be cut ; the six cyl cars have a removable piece in the middle ( to facilitate engine installation and removal as well as to position rad further forward ) . Think there may be an issue with engine mounts as well but not sure ...
 

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Quickie question, my navigation skills are proving less than optimal on the EPC - does anyone with a better idea of where to find the ECU and the EZL part number have those to hand, or can point me in the right direction. I don't like Ebay as a source as too often the parts are incorrectly labelled.

Thomas (not Julian, no idea how I got that in my mind) just asked.

I don't now have easy access to the EPC (thanks Apple) but, iirc, those parts used to be under 'Engine' - 'Electrical Components'
 
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Charles Morgan

Charles Morgan

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By coincidence I came across the same pages but thanks all the same.

I get the latest to be A0085456432 for the EZL and no currently available one for the ECU, but several others such as A0085451632.
 

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