280se to 500sec engine swap - HELP

[chodda]

Hello all,

as mine 500 SEC (1987) engine died .. I wonder can I swap it with 280SE engine that

I have
spare one in donor car (do I need to swap also auto transmission and differential from

same donor car
??).

280SE donor car is 1984.


any help is appreciated
TX!!

 

[turbopete]

id guess that it would be easier to find another 500 engine as this would require quite extensive work to change the wiring to suit the 6 cylinder engine, the transmission/differential MAY need to be swapped to get the gearing right for the engine and body weight, there would also be things like the rev counter (tachometer) to take into consideration as it would read incorrectly as its calibrated for the V8 engine, not the 6 cylinder engine, etc. also, id imagine most of the mountings for the engine etc will also need swapped over, as well as other items. so YES it may be possible, but i think it would be an awful lot more work than finding another 500 engine

 

[chodda]

Thanks turbopete

healthy 500 engine is hard to find over here,and this one 280 is just vaiting
to be born again ,...also i have to consider fuel consumption because the dragon 500 was like 30L/100km town and on 280se should be 16L/100km town ...just to save for the swap

I have tought that mounts are the same in those two models....??

respect
Chodda

 

[turbopete]

its possible that the mounts may be the same. im unfamiliar with either model so im not sure. they may be stronger or in a different position for the V8 engine. the swap is basically possible, but not as easy as it seems on the surface. if you have a complete car for parts though, it will just require time etc rather than too much expense, id imagine

 

[chodda]

also google is very cheap on some info for those older cars i.e I can not find acctual weight for 500 or 280 engine just to see if suspension also must be changed due to weight difference.....


old cars,........lots of trouble but I just like them )

 

[prwales]

from the info I have the se280 was 1560kg and the se500 was 1620kg so only 60kg difference.

 

[ianrandom]

I think the suspension is ok, it may sit slightly higher at the front but no other problems. The rest still stands though, possible but time consuming. The complete spares car will help a lot though.
Good luck if you do it.

 

[Alex M Grieve]

Thanks turbopete

healthy 500 engine is hard to find over here,and this one 280 is just vaiting
to be born again ,...also i have to consider fuel consumption because the dragon 500 was like 30L/100km town and on 280se should be 16L/100km town ...just to save for the swap

I have tought that mounts are the same in those two models....??

respect
Chodda

Is there any prospect of finding a diesel engine to install? Brianbrian on the Forum installed a diesel engine in an SL (R 129) with great success - and that would give you even greater economy and possibly better torque?

 

[turbopete]

Is there any prospect of finding a diesel engine to install? Brianbrian on the Forum installed a diesel engine in an SL (R 129) with great success - and that would give you even greater economy and possibly better torque?

very true, Alex, but a complete donor car would still be required ideally, for the gearbox/diff set up, wiring loom, dashboard differences (rev counter, glow plug warning etc) so again, not easy. certainly more tempting though!

 

[robparker]

w126's have horrible wiring loomes to work on if doing engine conversions as you cant just unplug them like on 124's, they are all intrograted into the main car loome, the mechanics of the engine swap are easy if you have the parts (mounts, exhaust etc) but the wiring you would need to know what you're doing.

 

[Gary Hanson]

Isn't the straight six engine slightly taller than a V8 ?
Might be worth checking the dimensions in case the front end of the six gets in the way of the bonnet closing.

 

[chodda]

Yes,I m also considering OM606 engine,but then again there are lots of issues about differential,..basicaly I have to find 260 differential and mount it with that diesel engine,and yes the torque will be awesome )

 

[chodda]

ok,it is finnaly done, I had to go with complete donor car 300sd,considering chasis and mounts that was best option... we had to mess a bit with diff from w124 300d but all has been fine now.

I have dropped 280se solution because over here I can not find a single one in good condition,and 300se was the only one that performed well considering engine quality,torque and rest....

If any of you guys have pdf for 82 300sd please let me know because I did not get owners manual with donor car. (or at least to state how much fluids are in which intervals...oil,coolant,brake oil...etc)

and btw which oil is best solution for this car? mineral or synthetic..considering my clima I shoul have 10w40 ....

TX