M103 3.0 to 3.6 Build Discussion
 

So the mystery has been out there, will a 350SDL crank fit into an m103, what else is needed to make this work and what will it actually do? Instead of a 350SDL crank for the conversion, would a C36 bottom end work better.
The last few threads date back to 2002 about this when most of us simply dismissed it under the fact that its too expensive.

Chime in if you have done this or if you have done research and you got stuck somewhere. And hey, if anyone wants to send spare parts my way, I can put them in the spare engine I have.
Let the brainstorm begin!!
Pete

I thought the 350sdl crank fit in the m104... Thats what I'm doing to my 104.... To my knowledge the m103 doesn't accept the 350sdl crank.... the crank will bring a m104 2.8 to a 3.6...
Kevin

Hi Pete,

From what I have "heard", from more than one sorce, the M104 3.2 block with the 350SDL 0M603 crank and M104 2.8 rods was used to make the AMG 3.6L M104. I have not personally performed the calculations to confirm this, but it sounds about right. The 3.0 M103 has a bore of 89.0MM and a stroke of 80.25MM. The M104 3.2 is 89.9 X 84.0 and the M104 3.6 is 91.0 X 92.4. This means that the 3.6L displacement is an enlargement of both bore and stroke. According to Ortolan, the 3.0 M103 will make 3.4L with C36 parts using stock (I think) pistons. Do the math and that should come out right. As for the crank, I don't know but it may need some alterations on a crank lathe in order to fit an M103/104. I suggest you contact Ortolan and ask him for the measurements of his C36 crank and rods to make sure.

While researching the project I read that increasing the bore of the M103 left the cylinder walls too weak. Apparently the Brabus 3.6L had a very short lifespan. This is why I elected to leave the bore alone and only increase stroke. The increased stroke also reduces the chance of detonation at the same compression ratio.

Brabus 3.6
 

From whom did you hear of the 3.6's apparently short lifes[an & what do you deem to be short? I have a Brabus 3.6 which has done over 130,000 miles, still going string (touch wood). I've done all the top end work (valve stems & guides, head gasket) due to a head gasket failure at around 100k but this is a common M103 fault. The car does consume some oil, in the region of a quart every 700 miles but tuned engines are such and I'm using Mobil 1 15W-50 Fully Synthetic, I may switch to a semi-syn as I've heard this will cut back consumption and may be better for an older engine.
The torque increase from boring the engine should not be overlooked. This really increases low down torque significantly well still having an apetite for the heady heights of 6550RPM. Do it!

Re: short lifespan of Brabus 3.6L M103.
http://community.190revolution.net/drivetrain-performance-modification/12350-300e-320e.html?highlight=brabus+m103

very interesting, so the brabus version that im looking to build is rather unreliable in the long run. Since these engines are so easy to come by, would a rebuild every 100k be such a huge issue or do they last less mileage?

I dropped my 300CE off at the workshop today, along with the C36 crankshaft and rods.
By next weekend I should know if the parts will work in my M103 block.
If everything is a perfect fit I'll order new bearings etc and aim to have the car back on the road by Xmas.
I'll keep everyone posted.

Incidentally, the custom suspension I purchased from ebay.de worked a treat.
http://cgi.ebay.de/Fat-Grip-Performance-Fahrwerk-Mercedes-E-Klasse-W124_W0QQitemZ230053203239QQihZ013QQcategoryZ70154QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

:D :D :D
Update: I went down to the workshop on my lunch break today and the engine and transmission are now completely disassembled. The first thing that caught my eye was the engine block upside down on an engine stand with the crankshaft sitting in the bearings.
I ask if that's the AMG crank and the mechanic says "yep, it needs different bearings but it looks like it should work fine". (a little bit unfortunate because the stock bearings look to be in brand new condition!)
He still needs to test if it will work when the crank, rods and pistons all come together (will hopefully know by tomorrow).

The next good news I got was that the block has been (partially) prepared for piston oil sprayers. I had read in an old thread that this was the case with M103s but it was a relief when this was confirmed. I have a set of 6 sprayers from an OM603 en route from Germany which should be here in 2 weeks.
The block needs to be sent out for the cylinders to be honed, which is going to set the timetable for completion. The head also needs to go out but there's enough of these that the shops work on a no-wait changeover basis. I'm still optimistic for an Xmas completion date.
The oil & water pumps need replacing along with the inlet valves and a few other minor parts. Two of the pistons have very light scratches due to the rings wearing away but the damage is so minor I'm not going to replace them.

This car is a bit of an enigma. I purchased it as an import from Hong Kong with unknown history. The odometer has less than 90,000km on it. The leather interior, metallic paint and many other components are in almost new condition and support the reading while other parts are very worn down and suggest the previous owner rolled the numbers back.
I took a bunch of pictures but forgot the camera at work. I'll post them all tomorrow evening.

D'oh, stupid gallery limits. :mad:
Anyway, here's 12 pics in reduced file size:
http://www.peachparts.com/shopforum/vbpicgallery.php?do=hall&u=31501

$%#!! :mad: :mad:
Just got off the phone with the mechanic and received some very bad news.
He attached one of the rods & pistons to the crank and put it back in the block to test clearances and found that the rod impacts the block by a fair margin.
THE C36 CRANKSHAFT AND RODS WON'T WORK IN THE M103!!

Now I'm at a loss as to how to proceed. I guess my options are:
1. Continue with the M103 rebuild using stock parts, turbocharge that and sell the C36 parts.
2. Put the M103 back together and sell it as a long block. Buy an M104 long block locally and use the C36 parts and machine the pistons to lower the CR, then turbocharge that.

either option sounds good.

the c36 motor in the car sounds good though. a two door would be sweet with that motor.

tom w

Is the piston at the correct height at TDC? (yes)
Does the piston skirt hit the crank throw at BDC? (no)


You sure you don't have enough room in the block to take a little off if the two conditions above are met?

One side of the cylinder could probably be machined but the problem is that the other side is where the oil nozzles must be mounted.
http://www.peachparts.com/shopforum/vbpicgallery.php?do=big&p=1491

My mechanic says he has found an early model M104 short block soon to be for sale which should fit the M103 head. I told him I was pretty sure the M103/M104 ends were not interchangeable but he says this particular block should work. He's going to call the lead MB technician in Australia on Monday to get confirmation.
I don't want to get my hopes up as this question has come up numerous times and each time the verdict has been that under no circumstances are the M103/M104 ends interchangeable.
My mechanic told me that there's not a single M104 for sale anywhere in the country at the moment (the one he found is still in the wrecked car and won't be removed for a few weeks yet).

i would try to find out WHY the heads are not interchangible. sometimes a minor amount of machine work would make it work.

i remember swapping heads left to right on my 51 caddy motor. the castings were the same but there was a tapped hole for a fitting on the firewall side. when put on the head from the other side we had to drill and tap on the back and plug the front. but the heads werent "interchangible" according to the book.

anyway i think the 103 104 blocks are pretty similar so knowing specific differences might allow you to do some simple things and use the setup you want.

good luck.

tom w

Make your own nozzles out of stainless steel tubing. Tap the block's oil holes, install a fitting at the end of you fabricated piston oilers, and there you go.

Has there been progress on this project? I have a few M103 motors I can get a hold of from my uncle. Was thinking of building one custom and swapping it for the stock and one in the car now.

Thanks,
Jason

M103 3.0 to 3.6 Build Discussion
 

I'm about to start this project next week, hope to punch out a m103 3.0 to a 3.4, this without boaring the cyl. Head being ported/polished now,euro sport cam on the way. Hope to have motor done and in the car by end Feb.

I purchased a complete 3.2L M104 last week which was delivered to my mechanic before he closed shop for the holiday period. When he reopens we will try to use this engine with the C36 parts. I will also see if the 84mm crankshaft & rods from this can be swapped into my old M103 for a more conservative displacement increase (extra 0.1L).
Bottom line on the previous swap attempt was that M103.983 crankcase & pistons + C36 crankshaft and conrods will not work, the rods hit the cylinders before getting to 90BTDC.

The guy I bought the C36 parts from in Germany remains steadfast that he has built a 3.6L M103 and that the problem won't occur if the cylinders are bored to 91mm and C36 pistons are used. Another German I spoke with says you need to use the crankcase from a 300GE model. What we know for sure is that a 3.6L M103 CAN be built.
This suggests that:
A) The extra 0.75mm of cylinder space on each side will allow the rods to pass.
B) The pin offset on the C36 pistons is different to the stock 3.0L pistons and this creates a lower rod angle at 90BTDC.
C) The 300GE crankcase has the cylinders placed higher and is what Brabus/Renntech etc use when building their 3.6L engines.

This may be the answer but the problem is if I bored the block and bought C36 pistons and it still didn't work I wouldn't be able to return the engine to it's original state.
Maybe someone in the USA can call up Renntech and ask what parts they use. I didn't get a response from my email.

Renntech
 

I'll call Renntech. Aren't they in Florida? I'll check the site and then give them a call. I would like to build a 3.2 or 3.6 out of a spare 3.0 M 103. Please let me know what I can do to be of any assistance. I've helped build mercedes engines before, 300Ds that were transplanted into Series 2A Land Rover 109"s. Friends of mine were sourcing trucks and motors from Germany and Switzerland. Both my friends speak fluent German so it was easy to get a hold of things over the phone.

Regards,
Jason

Wow, That Sucks! Are you sure you have the right rods? I do remember something about having to modify the lips of the cylinder bottoms to clear the rods. I'd get some more advice before scrapping the M103 block.

M103 3.0 to 3.6 Build Discussion
 

I'm attempting this build now. I just dropped in the crank and it fits and spins freely... Problem is with the rods, I thought the m103 2.8 rods would work but they are to long, actually longer than the stock 3.0 rods. Any ideas of which rods are the correct to use. With the 350SDL crank and stock rods the piston pops out of the cyl by about 1/16", with the 2.8 rods the piston pops out about 1/4"...
Gonna play around on the EPC and see whats up... If anyone has any ideas PLEASE reply...

I went down to my mechanic again today and compared the connecting rods up close.
The C36 rods I received are the same length as my stock 3.0L M103 rods.
I measured the rods (between the centre of each hole) at 145mm and the pin height (centre of pin to top surface of piston) at 34mm. These measurements were done very quickly and crudely using a ruler so they may be wrong by +/- 2mm.
My new 3.2L M104 engine is being taken apart this week so I will compare the rods & pistons from this engine when it's ready. I may also ask my mechanic to test the 3.2L rods with the C36 crank and 3.0L M103 pistons in the M103 block.

If the 92.4mm crank pushes the pistons out of the block by 1/16 (1.588mm) then the pistons should stop 4.487mm before the top of the block using the stock 80.25mm crank (the change in TDC position is half the increase in stroke, ie 6.075mm).

If the M103 has a 9.2 compression ratio, then the total volume of each combustion chamber at TDC is about 60mL (using the formula CR = (volume of chamber at TDC + displacement) / volume of chamber at TDC)
22.7mL of the chamber is thus located within the unused block with the remaining 37mL or so split between the piston valve recesses, head gasket and cylinder head.

For my 84mm to 92.4mm stroke increase my TDC position will be 4.2mm higher in the block (probably flush with the top of the block based on your info). This means that to maintain TDC position I need to use rods which are 4.2mm shorter or pistons with a pin 4.2mm closer to the top.
However, since increasing displacement while maintaining the same chamber volume will increase compression from 10:1 to 11:1, I will need to increase the chamber volume.
If I want to drop the CR to 9:1 for the turbos (and I probably do) then I need to increase the chamber volume to 73mL (36mL of it within the block) which means the 4.2mm has to become 5.7mm.
What stock rods are 5.7mm shorter than 3.2L M104 rods?

Is my math and reasoning correct?

If the 2.8L rods are longer it means the 2.8L engines probably use the same pistons as the 3.2L.

I think your math is ok.

But, are you allowing for the quench area? Changing the quench can cause serious mixture burn issues.

Does the M104 use much of a quench area? I've seen the pistons which appear to be flat top with valve recesses. I'm trying to recall seeing the underside of the the cylinder head.

Here's some comparison photos of the 3.0L M103 crank & rods vs the 3.6L M104 parts.
The C36 parts are the ones that look new and grey.
(images are around 200KB each)
http://members.iinet.net.au/~ortolan/300E_vs_C36_1.jpg
http://members.iinet.net.au/~ortolan/300E_vs_C36_2.jpg
http://members.iinet.net.au/~ortolan/300E_vs_C36_3.jpg
http://members.iinet.net.au/~ortolan/300E_vs_C36_4.jpg
http://members.iinet.net.au/~ortolan/300E_vs_C36_5.jpg

so the c36 rods are teh same as the 3.0 litre m103 rods.

Can you not get a set of c36 pistons? or at least the specs?

Yeah, the M104 piston is flat other than the fly cuts for valve clearance. The head has a soft pent shape.

With the numbers provided by basix, it sounds like the rods are the main issue in the combination. Has anyone had any luck contacting AMG or Brabus?

You can definitely see the extra throw on that crank. Pretty cool! Did you get the M104 apart yet?

Visually, the two rods are the same length +/- 1mm. The guy I purchased them from in Germany says the C36 rods are actually 1mm shorter (I believe it but it makes me wonder why AMG didn't just use stock 3.0L rods). He also said the wrist pin hole in the C36 pistons is higher than with the stock pistons (it would need to be). He's going to email me a photo of the two pistons together which I will post here.

My M104 is still being taken apart as of this morning. I'll visit the workshop tomorrow to check on progress and take some more photos.

M103 racing engine
 

BASIX, I am in the process of building an M103 stroker 3.6 for my racecar, could you get me the contact info for euro sport camshaft, assuming it is manufactured by Schrick.

The rotating assembly hadn't been removed from the block when I went to the mechanic today so I took some photos with the the 1st piston at TDC. It protruded about 0.5mm from the block. This 3.2L M104 engine has a 10:1 compression ratio and 84mm stroke.
http://members.iinet.net.au/~ortolan/E320block-1.jpg
http://members.iinet.net.au/~ortolan/E320block-2.jpg
http://members.iinet.net.au/~ortolan/E320block-3.jpg

Here are the comparison photos for the C36 pistons that I mentioned earlier.
http://members.iinet.net.au/~ortolan/C36_pistons.jpg
The size difference was more than I expected.

[QUOTE=Ortolan;1384850]
http://members.iinet.net.au/~ortolan/300E_vs_C36_1.jpg


It appears both cranks are cast from the thin parting line. Clearly the induction hardening is visible.

Any idea of a forged crank for the M103 or 04 engine? Aftermarket?

I'm selling my stroker motor project parts:

92.4mm AMG C36 crankshaft (used)
http://members.iinet.net.au/~ortolan/300E_vs_C36_1.jpg

Set of AMG C36 rods (new)
http://members.iinet.net.au/~ortolan/300E_vs_C36_2.jpg

Set of 89.93mm 3.6L 24v Oettinger pistons w/ wrist pins and rings (new)
http://members.iinet.net.au/~ortolan/oettinger_piston.jpg
http://members.iinet.net.au/~ortolan/oettinger_pistons.jpg

Set of OM603 piston oilers (new)
http://members.iinet.net.au/~ortolan/piston_oilers.jpg

If anyone is interested in some or all of the parts, make me an offer.
I'm located in Melbourne Australia so please remember to factor freight costs into your budget.

would any of these parts benefit a m103 N/A build?

The oilers would if you are prepared to tap your block in order to install them.

I have a 1992 300TE 4-matic with a RENNtech 3.6L M103 motor in it. The vehicle now has around 140000 miles on it with no issues. I wouldn't consider the reliability an issue. What a difference in the otherwise sluggish 4-matic-based M103!

Satish

M103 3.0 to 3.6 Build Discussion
 

Wow! Good news! Please post some pics if you can. Who made your rods? What pistons did you use? As for the porting, yeah it's a lot of work for maybe 10 or 15 CFM. I did it on my exhaust side mainly to keep it from soaking up heat.

http://img1.putfile.com/thumb/12/35519224626.jpg

http://img1.putfile.com/thumb/12/35519224691.jpg

All Pics...
http://www.putfile.com/hightechstuff2/images/65112

Well done!! Did you bore the cylinders out to 91mm?

M103 3.0 to 3.6 Build Discussion
 

No, I left the bore the same and running stock pistons. Lots of mixed opinions about opening the cyl walls. Based on what I learned the motor as is will make plenty of torque and it seems power from these motors really comes from compression, after shaving the head I'll be running 10.5:1 compression. Crower produced the rods, little pricy but got tired experimenting with off the shelf rods...

easy on the fonts there bud...

so is your final displacement still going to be 3.6?

Yeah, I know... No, 3.4 I'm actually more interested in torque as the motor will reside in a W201.

Do you have more info for the people you used for the rods. I have a line on a 350 crank, and have a junk motor.

:) You guys know your stuff no doubt.. but I passed quite a few c36 in my search for a low mileage one because of the high mileage (near 200k) until I found one with less of 100k, what do you guys mean by longevity? or is racers talk?