C36 Amg engine into R107 SL project

[bigben]

Hello,

I am new to this forum but thought I would start a thread on the engine transplant I am in the process of carrying out. Since the challenges are mostly engine related I guess this is the right forum.

The background is I have a 1989 300SL...

...which I have had for about 5 years now and really enjoy. However it was starting to look a bit sorry for itself so needs a fair bit of bodywork restoration (some of the panels are now a bit pink / rust coloured). Since the engine was going to have to come out anyway I thought why not put a more powerful engine in while I was at it.

So the search was on for a suitable engine, a bit of research showed that the engine used in the C/E36 was based on the M104 engine which is itself an evolution of the M103 engine that was fitted to my SL. As they used the same block this gave a great chance of the physical mounting points being the same. Eventually found a doner car at the right price....

....which looks ok in that picture but was a repaired Cat C write off. The repair apparently being carried out by someone without much idea about mechanics! The weekend after I collected the car I did this....

The following two weeks have been spent parting out the car and retreiving the wiring loom.

The project plan is now as follows:

- Remove engine from SL
- Replace with C36 engine, wire up and get running
- Remove C36 engine
- Get bodywork / suspension restored (the former by pros the latter by me)
- Re install engine
- Enjoy car!

I suspect this will take me at least a year, possibly more but no hurrry.

Any advice on the engine bit welcome, I am under no illusions that the wiring will be easy but have had the advantage of being able to save all the modules from the donor car and a background in electronics engineering.

The other bit I would like pointers on are removing the paint from the engine block which is flakey in places and finding some period wheels which can clear the massive C36 brakes that will be going onto the SL.

Cheers

Ben

 

[nick.ged]

nice project, should be a flyer when finnished, you will be able to swap the brakes over as well, might need to have some hoses with banjo connectors made up for clearance issues, but everything will fit.

paint from block will be messy, mabe just wire brush the loose off, and repaint?
keep us informed,

ps. mabe you should have put the post in the projects bit?

 

[nick mercedes]

nice project, should be a flyer when finnished, you will be able to swap the brakes over as well, might need to have some hoses with banjo connectors made up for clearance issues, but everything will fit.

W202 brakes are a bolt on mod for 107s??

 

[andy27168]

Hi,
Are you retaining the original 107 gearbox, or fitting the 5 speed C36 item?

 

[momomo]

Hi Ben, you made it over then! Its looking good. I must have missed your intro post.

Mo

 

[Sonny Burnett]

did u part out all the c36

 

[nick.ged]

107 500 brakes were used on the hammer, the hammer was a 124, 124 brakes fit 201, 202, 203, and 129, so yes the brakes from a 202 will fit a 107, the only problem may be the joints for the flexi hoses, wich might need to made up with banjo bolts on, like i did when fitting the black serises calipers on my 124.

 

[bigben]

Hi Ben, you made it over then! Its looking good. I must have missed your intro post.

Mo

Hi Mo,

Yes, you were right a great forum. Intro postt made a couple of days back.

To answer other questions the C36 has been more or less parted out have a few bits left that will go on ebay soon.

Could not post in the projects section as a mod needs to put it there.

I have already offered the brakes up to the R107 hub and they look like they will fit no bother. In fact the problem is the R107 wheels don't clear the C36 disks and I don't really want to loose the standard look. Having said that brakes were common across all facelift R107s so should be specced for the 560 hence man enough for what I am planning. Then again if anyone knows if the wheels I have came in any larger sizes that would be useful.

I may have the paint blasted from the engine but that is a ways in the future (after I have got it running and removed it from the SL) so will decide nearer the time.

5 speed gearbox will be fitted at the same time as the engine. I will be keeping the original engine and box in case C36 engine really does not suit the car at all (I really really hope this is not the case)

Cheers

Ben

 

[BlackC55]

what are you doing about the diff ratio?

 

[spanner]

I think 16" alloys from a 129, the ones with the same design as the 107 15" will meet your requirements.
Why didn't you just buy a 500?

 

[bigben]

I think 16" alloys from a 129, the ones with the same design as the 107 15" will meet your requirements.
Why didn't you just buy a 500?

Great, I did not know that they existed. An extra 1" would certainly give enough clearance it is very close as it is.

I did not want a 500 at the time as I used the car as a daily drive for some years. As with all projects like this it is hard to justify in any rational terms but will be an interesting exercise none the less.

what are you doing about the diff ratio?

Dunno yet. Could not get the diff out of the C36 in time to save it (has now been scrapped) so will worry about that when I have to!

Ben

 

[nick.ged]

with the c36 engine in it, a 107 will be a better drive, better on fuel, and out perform the 500 by miles and miles.

 

[bigben]

with the c36 engine in it, a 107 will be a better drive, better on fuel, and out perform the 500 by miles and miles.

That is what I suspect, although I did consider using an M119 V8 for this project as you can't beat the sound of a V8.

Ben

 

[spanner]

I own a c36 and a 300SL, amongst others, and whilst the C36 is certainly quicker than the 300, I'm not sure that it's THAT much quicker that it would justify the swap, especially given the 107's handling which is definitely not "sporty", even if the sub-frame bushes have been replaced. (hint).
Still, some things are worth doing just because you want to do it; I'm looking for a Pagoda to put a 3.5 V8 into. (Anyone got a pagoda with a knackered engine they don't want?)

 

[bigben]

I own a c36 and a 300SL, amongst others, and whilst the C36 is certainly quicker than the 300, I'm not sure that it's THAT much quicker that it would justify the swap, especially given the 107's handling which is definitely not "sporty", even if the sub-frame bushes have been replaced. (hint).
Still, some things are worth doing just because you want to do it; I'm looking for a Pagoda to put a 3.5 V8 into. (Anyone got a pagoda with a knackered engine they don't want?)

Since the plan was to re-build the rest of the car the delta in effort associated with carrying out the swap was less than doing the swap on a mint car which was a factor.

Suspension will be totally re-built with bushes, springs and shocks all being changed. Do you have a source you have used for bushes, in particular upgraded polybush type items ?

Ben

 

[jaymanek]

dont underestimate the 500 engine.... its very quick in the R107 IMO..

240 bhp vs 260 ish on a C36.

 

[Adam230K]

Thats a brilliant choice and I personally think it will outperform the same era 500 engine, 276bhp, much more advanced engine etc.. Look forward to seeing how it goes!

 

[SilverSaloon]

I know Derek (Druk on here) will be very interested in this..... he's away at the moment i think though

 

[bigben]

Small update. After a few weekends off doing other stuff I finally got some time this evening to start up the 300SL and move it out of the garage. After sitting for over a year it started first turn of the key and ran great (seems a shame to be taking the engine out!)

This weekend I hope to get the 300 engine removed, will be a bit easier now it runs as I can drive it up on to ramps to make the underside more accessable.

In fact all going well I may also get the 36 engine fitted, if not plumbed in and ready to go.

 

[BTB 500]

Good luck - keep us posted!