swapping motor into non mb questions - PeachParts Mercedes-Benz Forum

dragonbenz · #1 10-25-2005, 08:33 PM

ok have a question for you experts here. i have a 1981 MB 300d, with the 5cyl diesel motor, it has unibody damage in the front, and i now have it somewhat straight and driveable for the time being, but before too long i plan to swap the motor and tranny into another vehicle.
my question what stuff will i have to pull out of the mb and wire into the other car to make it work?i know there will be a bunch of trouble shooting in doing a swap into a completely different type of vehicle, which i will figure out as i go, but need to know the vital things to make the engine run.
a list of stuff would be greatly appreciated.
thanks in advance

t walgamuth · #2 10-25-2005, 11:53 PM

ignition switch, oil pressure guage, temp guage, i prob would try to use the benz instrument cluster if poss. prob the ignition switch is all you really need for it to run. or something that does all it does. it takes vacuum to the back of it. the vac lines from the engine to the tranny.

good luck

tom w

sixto · #3 10-26-2005, 12:51 AM

Glow plug relay. Convert to parallel type if the 300D has serial type.

I imagine you'll have to convert throttle control to a cable or fit the pedal and complete linkage from the 300D.

Sixto
87 300SDL

dragonbenz · #4 10-26-2005, 01:06 AM

ok so i need
ignition switch
instrument cluster
glow plug relay
anything else????
it wouldnt be a problem for me to just put the ignition switch from the benz in the other car, and i can most likely mod the cluster area to accept the benz gauges, as for the glowplug relay how would i tell which type it is? and as for throttle linkage it is already cable operated so i might be ok on that.
so far it sounds like very little to make this work,
is there any other vital gotta have things anyone can think of to add to the list
and thankyou to the ppl that have responded so far

t walgamuth · #5 10-26-2005, 07:46 AM

i dont know your level of experience, but swapping engines is never simple. even swapping within the same brand is not simple as there are a lot of little details that must be ironed out.

in example;

i once swapped a quadrajet onto my 3 liter bmw. i started with a euro manifold that fit the quadrajet except for relocating the mount holes .25" on two of the bolts. simple, right? well before it was over i had many many hours in making it work. i will list a few things from memory of 15 plus years ago. i had at least three different types of q jet on it before i found one that was satisfactory. and that one had to be rejetted. there was interference between the manifold and the mc booster. i tried a smaller booster that i got form salvage. it had to have bracket fabbed to fit the linkages. it was froma different model bmw. that didnt work. then i had the base of the manifold milled at an angle to lift it above the mc booster, and ground the corner off of the manifold, and finally put large washers betweent the engine mount and the engine to lift one side of the engine. that finally did it. and then there was the throttle linkage. i found a cable from a volvo that i adapted with brakets tha i fabbed by hand with flat stock etc. after all that i got it to work pretty well. that little six would really scream with 750 cfm of carb on it providing you waited til 3000 rpm to open the huge mechanical secondaries.

well you get the idea. this was a modification of just one system on the engine and i started with a manifold that matched perfectly except for two little .25" mounting holes.

an engine swap into a different model car is a daunting project. i dont know the failure rate of these in incomplete projects but it must be a lot higher than the ones that get finished.

it is an exciting and involving thing to do but not for the faint of heart, and it will help if you have a welder and machine shop at your disposal.

it is a lot more postitive hobby than going to the bars but if you are married it might be almost as much a strain on your wife.

good luck

tom w

dragonbenz · #6 10-26-2005, 11:34 AM

let me reiterate what i said a little, i meant that it was easy on what parts i needed to take out to swap over, i know an engine swap is never really easy, and i dont plan to modify the engine itself, im expecting to have mounting and clearance issues more than anything else, and of course the little stuff
and i am maried but the initial idea was actually both of ours!!!lol and she said she would help.

t walgamuth · #7 10-26-2005, 06:52 PM

very special wife. hold on to her. sometimes i ramble on too much.

good luck

tom w

dragonbenz · #8 10-26-2005, 08:23 PM

lol its all good tom, and yeah she is special, after 8 years i can still get her to help me with my hair brained ideas lol
so im guessing there isnt some type of ecm on this then? i would really rather not have to use that MB fuse panel if i can help it.

t walgamuth · #9 10-26-2005, 09:49 PM

computerized engine managment, no. none with a diesel til maybe 85? not sure. i have not had a five with computer.

good luck

tom w

dragonbenz · #10 10-26-2005, 10:07 PM

thanks thats good news to hear 1 less thing i will have to worry about on a swap then

p.s. i havent mentioned the car i will likely swap the motor into since if i did i would likely be banned from the site lol

dragonbenz · #11 10-26-2005, 10:12 PM

actually did just think of 1 important question, what is the rear differential gear ratio?? and depending on what that is will the tranny still work with a rear dif with a 3.90 gear ratio???

t walgamuth · #12 10-26-2005, 10:16 PM

ratio is 308. with a 390 you will be screaming on the highway unless you are running very tall tires. come on now tell us the brand or pm me. i wont laugh. believe me i have had some pretty goofy ideas through the years.

an el cambenzio for example.
tom w