HELP! - New Engine - 1979 Mercedes 409

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M102.982​

Similar to the M102.980 version, but with the newer KE-Jetronic system from Bosch. Cubic capacity: 2,299 cc (2.3 L). Power output: 97 kW (132 PS; 130 bhp)

Applications:



50% MORE POWER? Only snag with these engines is the EZL ignition units so make sure the engine comes complete with all ancilliaries inc the fuel system pumps filters etc


Mercedes-Benz TN - Wikipedia lists engines fitted
Does the OP's gearbox mate with an M102? If not, is pulling an M102 out of a rotten saloon complete with its gearbox (manual or auto) viable?
Strikes me the M102 is the most suitable engine here being a solid 2 valve/cyl motor with good low/medium speed torque.
 
If you haven’t already it could be worth trying TM Motors in West Molesey. They do classics and restorations as well as modern stuff. They really seem to know their stuff and are great to deal with. They sorted an issue for me that another Indy specialist couldn’t so I always go to them now. But their skills mix might be useful for your issue?
 

Does this look anywhere near helpful
To me, that looks pricey and incomplete. There needs to be a lot of parts carried over from your existing engine(s) and apart from being labour intensive, all it needs is for a part to not quite fit (eg, change of bolt spacing) and the labour input required ramps up significantly. Unless there's a desire to keep the bus original then I'd think about moving beyond the M115 engine.

I think the M102 is the obvious choice and one complete and with a gearbox could likely be obtained from a rotten saloon in the UK as it was used extensively and was the engine that replaced the M115 in the W123 series. More plentiful than the M115 which the pricing seems to reflect its rarity and will get scarcer still in the future. I'd also look at getting its gearbox with it and use it if the ratios are suitable. Any problems matching clutch, release bearing, slave cylinder etc will be time consuming to resolve.

Only my opinion - see what other comments ensue regarding the M115 available to you and whether the M102 is as suitable as I imagine it.
 
If you haven’t already it could be worth trying TM Motors in West Molesey. They do classics and restorations as well as modern stuff. They really seem to know their stuff and are great to deal with. They sorted an issue for me that another Indy specialist couldn’t so I always go to them now. But their skills mix might be useful for your issue?
Thanks very much Chris - I am waiting for their call back. Fingers crossed
 
To me, that looks pricey and incomplete. There needs to be a lot of parts carried over from your existing engine(s) and apart from being labour intensive, all it needs is for a part to not quite fit (eg, change of bolt spacing) and the labour input required ramps up significantly. Unless there's a desire to keep the bus original then I'd think about moving beyond the M115 engine.

I think the M102 is the obvious choice and one complete and with a gearbox could likely be obtained from a rotten saloon in the UK as it was used extensively and was the engine that replaced the M115 in the W123 series. More plentiful than the M115 which the pricing seems to reflect its rarity and will get scarcer still in the future. I'd also look at getting its gearbox with it and use it if the ratios are suitable. Any problems matching clutch, release bearing, slave cylinder etc will be time consuming to resolve.

Only my opinion - see what other comments ensue regarding the M115 available to you and whether the M102 is as suitable as I imagine it.
Thanks - I would like to keep it as original as possible really! do you please have any suggestions of a year and model car that I should start looking for. I am pretty resourceful at finding things. Just clueless technically!
 
Thanks - I would like to keep it as original as possible really! do you please have any suggestions of a year and model car that I should start looking for. I am pretty resourceful at finding things. Just clueless technically!
Re the M102 here >> Mercedes-Benz M102 engine - Wikipedia gives the models it appeared in.
Seems to have been around since 1983. The W123 started life with the M115 engine and got the M102 around half way through its model run.
Earlier cars featured the 2.3. The 190 only had a 2.0 as it's biggest four cylinder engine (the 2.6 was six cylinder) and it's later 1.8 version was prone to blowing head gaskets. All M102s are a little prone to this so if buying one look out for that and any damage caused by it. It could be why the car fell out of use if it's been sitting. Ideally a corrosion riddled MOT failed W124 with a strong engine turns up locally!

See what the rest of the forum thinks before jumping. If you want originality then a M115 it must be. If you do buy the ebay one, at least you have your old engines for spares. It is possible a W114/115 so rotten as to be beyond redemption appears ready to donate its engine but they are so collectable now that there are those willing to repair all the corrosion they suffer.
 
Thanks for the advice. I would dearly love to get an updated engine. I just don't have the ability to organise this myself and to be honest there are so many multiple ideas, opinions, and options that I am as confused as hell. I clearly need to find an expert that can take this project on and help me get it running.
Sorry you are confused but there is no easy answer to this just a series of options of varying complexity and cost. The professionals capable of doing this sort of work -sourcing a suitable replacement engine* and gearbox -original or substitute type and then fitting don't come cheap and these jobs are labour intensive.
Due to so many unquantifiables many would only contemplate an open ended ongoing cost approach and would be reluctant/unable to accurately cost such a job at the start. The only ones who might----and this is the first question to ask them - is how many of this particular model have you worked on/repaired/restored/converted mechanically?---you might have better luck on the camper van forums?
 
WhatsApp Image 2021-08-04 at 07.48.50.jpeg

There isn't a lot of space in there for alternative engines, less so for those that cant to one side.
 
View attachment 116486

There isn't a lot of space in there for alternative engines, less so for those that cant to one side.

There is more space there than you might think, but the question you need to ask yourself is how original do you want your van to be?

Do you want an m115 engine as the factory intended, slow, thirsty, but original.

Or do you want to update it for reliability and modern traffic conditions, but loose that originality.

Once you have decided that you can proceed.
 
There is more space there than you might think, but the question you need to ask yourself is how original do you want your van to be?

Do you want an m115 engine as the factory intended, slow, thirsty, but original.

Or do you want to update it for reliability and modern traffic conditions, but loose that originality.

Once you have decided that you can proceed.
Great question - I guess the later to be honest really
 
Great question - I guess the later to be honest really
Ok, just out of curiosity go grab a tape measure.

We need to know the length between the radiator and the rear of the engine compartment. Also the width inside the engine cover, and how far back the gear lever is from the engine cover.

We also need a pic of said engine cover to see it's shape, and a pic of the engine bay from the front of the van to see the layout.
 
Hi,
Any update on the progress. Just being nosey !

Steve.
 
Hi,
Any update on the progress. Just being nosey !

Steve.
Hi Steve,

Thanks for checking in mate!

Well, the solution is on the way, BUT I may well have committed financial suicide as she is now with a Mercedes main dealer down in the SW! I do know the guy that owns the franchises so fingers crossed. - I thought I would share the below as we had so much helpful interest..

"our mechanic worked his magic and got her started on Friday late on which was great news! She was running lovely until we put some coolant in the vehicle. Once we filled the vehicle up with coolant the engine started to splutter and emptied the contents all over the workshop floor.

The issues we found were as follows:

· The timing was completely out, approximately 15 degrees from TDC (Top dead center) the TDC is vital as it will allow the exhaust valves to close when the intake valves are open and vice versa, without it being TDC both sets of valves would be open and the engine would have little to no compression.

· Spark plugs were the incorrect ones and completely blocked with carbon deposits and general engine sludge. (See picture below, they are supposed to be lovely and shiny!)"


image001.png

"· One of the fuel hoses was filling the top of the engine bay with fuel, which could have caused a nasty fire, so this has been cut back and refitted.

· The coolant hose was also split and perished, so this has been rectified."


image002.png



"So, the positive news is that the engine seems to be mechanically sound. It just needed some TLC and a few basic bits setting up, so we will be pointing the finger of concern at the cylinder head gasket leaking causing coolant to leak internally into the cylinders and externally all over the floor.

What do we need to do?

Well, the starting point to bringing Betsy back to life is the cylinder head will need removal and sending for pressure testing, we can organize this locally. While the head is being pressure tested we will ensure that it is skimmed so that we have a flush surface to work with which will also improve the compression in the cylinders.

The head gasket will need replacing along with the engine oil, oil filter, air filter & fuel filter. Once we have the correct engine pressure and sealing we will be able to check the condition of the radiator, often the head gasket fails when the engine overheats, which can be caused by leaking radiators or coolant pipes.

The main goal at the moment is sourcing parts, as you can imagine they are a little harder to obtain on these vehicles, but we are fortunate that we have a couple of parts men who know their way around the classic Mercedes and where to look for things."
 
Hi,
Thanks for the update, I am very pleased for you that Betsy will live again. Taking the head off is no problem, there is plenty of room for that, ( been there and got the t shirt for that ) and I am sure you will find a new head gasket some where. Getting the head sorted was on the cards no matter what, as you will need new valve seats, ( to use 2 star fuel ) and probably valve guides. Hopefully, the valves will clean up and save you a few shillings. While the head is off it will give you / someone, a chance to check the bores and have a look at the condition of the pistons.
I hope you will keep us all posted of what is happening. At the end of the day, this is all so much easier than switching engines.
Happy Days ....Steve.
 
Some news from the MB garage on Betsy. - Such great guys and the mechanic has 40 years of experience!

"We have removed the cylinder head and confirmed the head gasket had failed in a spectacular way, so the cylinder head is off to the machine shop to be pressure tested and skimmed to ensure it hasn’t distorted from the head gasket failure.

Once the head was removed we could inspect the internals of the engine and found the crankshaft gears have suffered some damage due to the engine running out of time, so we are going to send this off to the machine shop to see what we can do with regards to replacing the damaged cogs.

We should have the results of the testing from the engineers and I will update you further.

The good news is that we have found the issues, and once reassembled and timed up correctly it should run a lot smoother and give you a bit more power, but the bad news is that they didn’t have a great deal of oomph when new, so it will be better but not earth-shattering!"
 
Garage Update -

IMG_0668.jpgIMG_0669.jpg
The majority of the parts have now arrived, so we are currently in the rebuilding process.
We are aiming to get the engine rebuilt and installed over the next week or so.
Once we have it assembled we will give it a good road test and report back.
Attached are some progress pictures for you
 

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