Looking any info on a Mercedes 409 M 115 engine swap

[409LF8]

Hello

I have a 409 truck with a 2.3 litre petrol. It run's out of steam going uphill especially when towing and on a recent run to Brighton and back from Lincolnshire I spent £320 on fuel, so about 8mpg.

I would like to swap the engine for something with more power and economy.

Does anyone know of any similar swaps or have any info on what engine would be suitable. The only instance I could find was a guy in canada that swapped in a 4BT Cummins, but he ran into problems with gearing and was talking about swapping the rear axle and then the thread ended.

I use the truck for business, and would like to travel to events without it costing a fortune. https://www.facebook.com/thefireandicetruckUK/

 

[carat 3.6]

I think I would be fitting the om602 2.9 turbo diesel, that will have enough power for what you need.

There are other options but it comes down to money and time.

 

[toolman1954]

Hi,
How nice to see one of these old girls again.I had a 409 van in about 1985/6 and used it for my markets/tool selling business. In the mid 80'sall the lads on the markets were using 407's and 408's and I turned up in a 409 which then was quite a rare bird in those days. The 407 was only 70 hp and very underpowered. The 408 was 80 hp and better, but I had 90 hp out of the 409. Not until the later shaped 410's did you get 100 hp and not until the 312 sprinter did you get a turbo engine in a van ( under 3 1/2 tonnes), and my Sprinter, which I have had for 13 years flies when empty.
So to address your problems. There was a petrol engine in your

 

[toolman1954]

Hi,
How nice to see one of these old girls again.
I had a 409 van in about 1985/6 and used it for my markets/tool selling business for about 3 years until I got myself a 508D.
In the mid 80's all the lads on the markets were using Diesel 407's and 408's and I turned up in a Petrol 409 which even then was quite a rare bird. The 407 was only 70 hp and very underpowered. The 408 was 80 hp and a bit better, but I had 90 hp out of the 409, last number always relates to the HP. Not until the later shaped 410's did you get 100 hp and not until the 312 sprinter did you get a turbo engine in a van ( under 3 1/2 tonnes), and my Sprinter, which I have had for 13 years flies when empty.
So to address your problems.
There was a 115 petrol engine in your Fire Engine purposefully to stop the fuel freezing in winter times, as did Tanks and the like.
I seem to recall getting about 20 mpg or so out of my van, which was always "well loaded up" and I still managed 60 mph on the motorways.
Your £320 worth of fuel for 370 miles ( I used Grantham to Brighton @ 185 each way) equates to 7 mpg which is terrible. The 409 is a heavy van, have you ever weighed your van in its Fire Engine livery.
The 115 (952?) 2.3 engine was supposed to pull 3.5 tonnes so where is yours failing?
Before you go down the route of an engine change, what is the condition of your engine.?
With the cover off, there is plenty of room to work. I recall, taking the head off of mine to replace a broken valve guide without any undue problems.
Have you looked at the plugs, done a compression test, checked valve clearances, or even a Colourtune test, renewed or rebuilt the carburettor, it might even need a new set of rings depending on the mileage. For 7 mpg something must be wrong and may be easier to fix than a replacement engine.
If you must change the engine then perhaps consider another 115 engine to preserve the vehicles authenticity. A 951 from a 230/4 is 110 hp and a 954 out of a 230T is 109hp. Just a bit more than your present 90 hp.
Your Fire Engine is a lovely looking vehicle and it is sad that during my time selling at Steam Rallies over the last 30 years our paths have not crossed, it would have been nice to see it close up.
As a left hand drive it must have come off of the continent, so where did it originate from. ?
Try to come back and keep us posted of your progress with it.
Cheers Steve.

 

[409LF8]

Steve

It starts and run's fine, apart from the odd cold morning it needs full choke and a few stamps on the gas. After running for a few minutes the exhaust is clear, no blue smoke or anything.

When I bought it, it had only covered 38.000 km from new.


Yes from what I can find it should have the M115.952 variant, which is almost the same as the one in the 230 of the same era.

It will do 60 on the flat even fully loaded and towing the Sankey trailer and 70 downhill, but throw in a steep gradient and it drops off, to the point I have to grab third gear and have it roaring along at 35-40 until I crest the incline, gentle gradients are ok as long as I get a good run up.

The compression gauge sits at the top when running 4.5 out of 5 ( not accurate I know) and it runs fine.

Not had a look at the plugs or carb yet, but will do when time and funds allow it. I can't get in too deep, as we need it most weekends to travel to events, but have ruled out anymore Brighton or London trips as fuel costs are too high.

It does have a cracked exhaust manifold. All M115 petrols were prone to cracking it seems and I searched for weeks to find one to no avail. I even spotted an add on a german mercedes site, from a fire service in Bavaria looking for the same part as me. I was told the manifold from a 1977 230 2.3 was the same, so I bought one form a breakers in Kent. It looked very similar, but the goose neck is too shallow, so a no go.

I researched a repair and apparently the best way is to mig weld it with stainless brazing wire, which I bought but, don't want to attempt at the moment as I don't want a dead truck. I also looked at getting a new header manufactured and all quotes were £1200+ so too rich for me just now.

So for now I have used high temp magic metal and racing exhaust wrap which has made a big difference to the noise levels.

Our truck was in service until early 2016 I believe in a small provincial town called Wallenborn in the Rhineland. I have found a few photos of it in service somewhere rural , a few of it with groups of fire service cadets and school trips and outside the fire house with it's successor. Underneath the existing graphics I can see another set of faded numbers and logo, so it must have had two homes in it's working life.

Ronan

 

[409LF8]

Had the carb stripped , cleaned and rebuilt, then installed a loud free flow exhaust and its made a big difference to fuel consumption and power available.

But now I have a bigger problem. Came back from picking up a 1968 trailer to re-furbish , just turned into my street and engine started to knock, managed to get it on the drive and it sounds like it's a big end bearing on No 1 maybe.

Was hoping to drop the sump and do a in situ bearing replacement, but it's not really possible on this engine as the crankcase cover appears to be attached to the gearbox housing, has allen head bolts instead of hex head and there's a cross beam in the way,

so I would have to hire an engine hoist and to pull the engine and gearbox out and strip it down on the driveway and try to repair it.

I have had enough of this damn engine and it's oddball ancillaries, can't get a carb or manifold for it anywhere and now it's thrown a bearing too.

I need to find a relatively easy swap and have spent days trawling forums and the web for information and can't find anything regarding a swap apart from some guys in canada putting in a 4BT Cummins, but with little info and then the project seems to have been abandoned where they could only get 55km/h.

I would like to find something that would bolt straight to my existing manual gearbox which I can find no info on other than it's part number 3092601701 , tried googling it and all I get is mainly russian and french pages about merc transmissions with no relevant info.

Or just replace the engine and gearbox completely, prefer petrol as it would be much harder to convert to diesel.

I just have no idea what would fit, if anything or whether another engine/gearbox combo would go in.

Sorry for rambling, but no idea what to do next, can't afford to get someone to try to sort it either.

 

[E280Tim]

Have you seen this link?

Mercedes 409 Austrian Ambulance 4BT Swap

 

[E280Tim]

Not successful but interesting

 

[E280Tim]

I've had a number of Sprinters including a 312 and a 412 and I would say the engines are really good and have plenty of power.
Why not buy an accident damaged 312 and change the whole lot?

 

[409LF8]

Yeh that's the one I mentioned , not successful, so of no use really.

Yes, maybe need to look at sprinters and vito's, see if any thing is useful. No room for anything else on drive though.