Hi everyone i am a newbie, and i own a very mint condition 500sl 1990 model but it was overheating and broke 2fly wheel gears. i have managed to source a very good transmission and motor with 63k on the clock from a 1994 320 sedan. can i fit this engine in my 500SL Body without major mods, i have no issue with the downgrade all i want is my car back on the road.please guide.

 

moved to R129 forum...

 

Hi MB members any help on my post over the engine swap?

 

Well now that the important task of inspecting that woman's tiny shorts has been duly completed, I would say that your swap of the engine and transmission will work in converting a SL500 into a SL320.

That said, you will also need to swap in the rear differential from the SL320, possibly along with the drive shaft, to replace the one that came with the SL500 drive train, since the gear ratios of the rear pumpkins are dramatically different from one to the other. The car will NOT drive normally if you do not replace the V8 rear diff with one designed for the 6-cylinder variant of the R129.

 

Bravo Merc Mania,

i will do just as advised because i have everything needed, i am basically doing a transplant..i bet the wiring wouldn't be a pain in the rectum?

 

though its sad to step on a v8 into a straight 6.

 

Honestly I cannot offer any pointers on the wiring aspect of this transplant, but I see you are in Zambia, and a lot of credit must be given to Africa's shade-tree mechanics, so they will likely find a work-around solution to any electrical gremlins that appear during the surgery.

Let us know how it goes.

 

Hey Mania careful with teasing Africa's under a tree mechanics they have proven genius over the years. i have one friend that has converted a Mercedes benz G Wagon to a "MERCEDESBMW" lol. he has put an M50 BMW engine in the wagon and it drives superb.

The thing is these engines M119 are kind of sophisticated but i love the power and all just that every garage i go to even the dealership is advising me to take the car to South Africa which is quite a tedious process and costly at the same time. at some point i thought of going 1uz but i am told i need to find a fuel management system as it cuts raves at 3000rpm after conversion.

 

I agree that quite a number of the poorly equipped and often uneducated outdoor mechanics of Africa are highly skilled in making do with less, and getting cars running despite all odds. I should know because I hire them all the time, and have never taken any of my old Mercs to a "modern" mechanic's workshop in my neck of the woods.

In your instance, unless fuel costs are prohibitive in Zambia, I would advise that you take a little more time to look for an M119 engine from ANY other members of the Mercedes family from that era that were powered with the M119 "bullet proof" engine. Accessories such as the water pump, oil sump and such may need to be transferred to the junkyard engine from the one being removed from the car, depending on the particular model of the donor Mercedes.

Going from a 5 liter V8, to a 6-cylinder engine, fuel savings will be negligible, while the degradation in horsepower WILL be noticeable.

Of course I am sure that you are aware about the importance of IMMEDIATELY replacing ALL the upper plastic timing chain guides on ANY M119 V8 engine that you buy, and, if you can afford the cost, replacing the timing chain and chain tensioner would be very good insurance on a higher mileage engine. Check Wikipedia for the long list of Mercedes cars that are powered with the M119 engine.

The R129 is a heavy vehicle, for its size, and going through all the trouble of replacing the entire drive-train just to install a much less powerful engine, is to me a far less preferable option than patiently scouring the junk yards for a nice V8 M119 engine as a direct replacement for the one currently in the vehicle.

Today, I have sent off for a scrap-yard R129 that is complete and entirely rust free, but not running. I am buying it for a couple of hundred US dollars equivalent, and for that pittance, I get another possibly sound M119 engine, a transmission, perfectly straight body panels all round, complete exhaust system and all undercarriage components.

These cars are a rarity in Africa, so my find was a stroke of luck. Before you actually commence this transplant of a lowly six-cylinder engine into your V8 powered R129, I would suggest that you make inquiries in junk yards, and among those familiar with old money families in Zambia where you are, and, with some patience, you may well snag a whole donor car at reasonable cost, thereby preemptively solving several current and future parts related problems at once.