Engine Swap Questions M120 into 380SL - Page 2 - PeachParts Mercedes-Benz Forum

duxthe1 · #16 03-21-2006, 08:11 PM

Sorry but I don't have pictures of someone else's car. The area in question is near the idler arm, that I am sure of. And yes the 5.0 was offered but there was more room engineered into that area for those cars, which yours is not. I'm not trying to B/S you. I am a 10 yr M/B tech. On any given day i can be working on both 107's and V12 cars. Heck, there is a 380 SL in my shop sitting without an engine in it. I know exactly how much room you have. I also mentioned the idea around the shop (mercedes only independant) and everybody chuckled and then agreed, "no way in hhell"

I'm sorry that I'm the only voice of reason here but I am trying to tell you that you have no idea what it will take to put a m120 into a w107. I can promise you it will exceed any notion you have by an enormous percentage. As a rough guess I'd bet you'll have to re-engineer at least 50% if not 75% of the entire car. If it were even remotely feasible don't you think someone would have done it by now? Hell, I've seen V12's stuffed into a C-class but you're talking about a 6 figure price tag on the conversion. Are you really serious about dropping that kind of scratch on one of the lamest of all SL's?

Roncallo · #17 03-21-2006, 09:44 PM

Quote:

Originally Posted by duxthe1

Sorry but I don't have pictures of someone else's car. The area in question is near the idler arm, that I am sure of. And yes the 5.0 was offered but there was more room engineered into that area for those cars, which yours is not. I'm not trying to B/S you. I am a 10 yr M/B tech. On any given day i can be working on both 107's and V12 cars. Heck, there is a 380 SL in my shop sitting without an engine in it. I know exactly how much room you have. I also mentioned the idea around the shop (mercedes only independant) and everybody chuckled and then agreed, "no way in hhell"

I'm sorry that I'm the only voice of reason here but I am trying to tell you that you have no idea what it will take to put a m120 into a w107. I can promise you it will exceed any notion you have by an enormous percentage. As a rough guess I'd bet you'll have to re-engineer at least 50% if not 75% of the entire car. If it were even remotely feasible don't you think someone would have done it by now? Hell, I've seen V12's stuffed into a C-class but you're talking about a 6 figure price tag on the conversion. Are you really serious about dropping that kind of scratch on one of the lamest of all SL's?

Sorry I dont mean to start a flame war here. But so far you have given me no useful infomation. If you want to help give me the number in inches or pounds that you feel is going to knock this project out of the relm of practicality. I have also worked on MB for 10 years from 1978 to 1988 so I have never seen an M120 engine except in pictures. I have done some challenging engine swaps including Chevy 350 into a Ferrari 308 GTS and Ford 302 into a Pinto. I have recently seen an artical on the web of and M100 6.3 iron block engine installed into a 113 280SL. I'm sure that engine is much heavier than the M120 and the car is smaller than the 107. I am now an Areospace engineer and quite well acustomed to such challenges. I also have a full machine shop at my house.

Numbers please, "no way in hhell" is not a number

John Roncallo

duxthe1 · #18 03-22-2006, 12:06 AM

The best "useful" information I can give you if you are determined to pursue the project: Get rid of the 380 and get a solid 560 SL and start from there. The 560 is the better enginered and built of all of the 107's and is where any serious attempt at a V12 W107 should start. Take that to heart. I'd really would love to see you pull it off. (I've built a V8 pinto myself.)
I think it will require an extensive front suspension and subframe modification. The tranny tunnel is really low in that chassis and getting the 12 to sit low enough is gonna require a lot of room that isn't there to start with. The 107 doesn't have the typical "firewall" space so you have to get all your "extra" space low and forward. You're likely to have interference at the steering gearbox, idler arm, and possibly upper control arm inner mounts, as well as the subframe, drag link, and damper. The subframe ties the front suspension together and any serious modification will essentially require a redesign of the front suspension. As mentioned before, the brake booster is gonna interfere with the intake which is huge. You're gonna have to get creative there. Something like a hydraulic brake booster maybe? A rack and pinion may just solve the gearbox, idler arm drag link issues. The 560SL has a diff I believe strong enough to hold up to a 12 and hydraulic rear shocks. The hydraulics in the rear have a "ladder bar" affect in that it lifts the rear of the car during a squat, (ie hard launch)
No flame war intended. I should have realized that "trust me" wouldn't suffice for a reason "why not"

If you are up to the task, then kudos,

go for it. But as you may start to realize it will be a major undertaking. If you're emotionally attached to the 380 SL then build up a V8 and concentrate on upgrading the chassis to 560 specs. You'll find that to be much more rewarding. You'll be able to upgrade different things along the way and be able to enjoy the car in the meantime. The option is to strip the whole front end off the car, position the engine/tranny, and re-engineer the understeering, stoplight terror around it.

t walgamuth · #19 03-22-2006, 07:38 AM

is a problem, and i can see how it may be, i bet 107s were offered in some markets with manual brakes. i know the big bimmers (euro) were at least around 1980. i drove one. it worked fine. i suspect that the non power master may run a smaller diameter piston for more mechanical advantage.

tom w

Roncallo · #20 03-22-2006, 06:50 PM

Quote:

Originally Posted by duxthe1

The best "useful" information I can give you if you are determined to pursue the project: Get rid of the 380 and get a solid 560 SL and start from there. The 560 is the better enginered and built of all of the 107's and is where any serious attempt at a V12 W107 should start. Take that to heart. I'd really would love to see you pull it off. (I've built a V8 pinto myself.)
I think it will require an extensive front suspension and subframe modification. The tranny tunnel is really low in that chassis and getting the 12 to sit low enough is gonna require a lot of room that isn't there to start with. The 107 doesn't have the typical "firewall" space so you have to get all your "extra" space low and forward. You're likely to have interference at the steering gearbox, idler arm, and possibly upper control arm inner mounts, as well as the subframe, drag link, and damper. The subframe ties the front suspension together and any serious modification will essentially require a redesign of the front suspension. As mentioned before, the brake booster is gonna interfere with the intake which is huge. You're gonna have to get creative there. Something like a hydraulic brake booster maybe? A rack and pinion may just solve the gearbox, idler arm drag link issues. The 560SL has a diff I believe strong enough to hold up to a 12 and hydraulic rear shocks. The hydraulics in the rear have a "ladder bar" affect in that it lifts the rear of the car during a squat, (ie hard launch)
No flame war intended. I should have realized that "trust me" wouldn't suffice for a reason "why not"

If you are up to the task, then kudos,

go for it. But as you may start to realize it will be a major undertaking. If you're emotionally attached to the 380 SL then build up a V8 and concentrate on upgrading the chassis to 560 specs. You'll find that to be much more rewarding. You'll be able to upgrade different things along the way and be able to enjoy the car in the meantime. The option is to strip the whole front end off the car, position the engine/tranny, and re-engineer the understeering, stoplight terror around it.

I actually do not have the car yet. The 560SL is the chassi of choice if I can find one.The 380 was mensioned as a worst case starting point from the possibility of using a modified 380 transmission. But since it wont bolt up to the M120 and the are no B&M performance parts available for MB transmissions use of the stock transmission has become a moot point. At this time I am looking at a 560 with 200K miles on it. A straight body is my biggest concern.

The tunnel area I belive I should be able to be enlaged and still use the stock console. Keeping the car stock looking inside and out is one goal. The subframe is one part that may make the job somewhat easier. The subframe can be completely removed and redesigned allowing me to work arround obsticles.

The power booster I'm not in the least concerned with. But I belive the radiator will have to go and finding a safe place for those might be challenging.

John Roncallo

jhodg5ck · #21 03-23-2006, 08:35 AM

just a quick aside, but the 560SL is standard suspension, @ least all the varients (including my own) that I have come across. An SL w/ SLS sounds interesting though!

You might want to consider, given the space limitations, installing the euro spec oil and transmission coolers. They sit off the side, typically under the front fender wells. Going this route might make it possible to cut down on the overall size of the rad you will need. You might talk to Ron's radiators, the work they do is first rate.

Just to add some more conversion work fuel to the fire I'm waiting on a C36 driveline to show up so I can start adapting my 64 Austin Healey to run it...Should be fun

Best of Luck!
Jonathan

BobsterMan · #22 03-31-2006, 10:44 AM

This elegant debate is more interesting than my 280C with American v8 ponderment. Can the previously otherwise mentioned Mustang II front end solve the problem, or are we looking at the Ford assembly being too light, or is it a MB manhood issue? If I was gonna stuff that beast v12 somewhere, it would have to go mid-engine for center of mass. gravity, and inertia. Sure wouldn't want to enter a wet road under yaw and power with it hanging out the front of a "moped". I'm going with the souped v8 and suspension improvements.

t walgamuth · #23 04-02-2006, 06:16 PM

that the v12 weighs much if any more than a 617 turbo.

but if you want to go with the ford, i am pretty sure they were available with several sump locations. check bronco and truck listings and see if you cant find one that fits a benz.

tom w

Richard Wooldridge · #24 04-04-2006, 01:37 AM

Hey Bobsterman,
Sorry to depart from this interesting discussion on the merits of the V12 swap, but I have to ask the Bobsterman about his "ponderment"! I have a nice '75 280C, and have considered installing a GM 4.3L V6 to replace the very tired 110 engine now residing between the front wheels. I have also considered just installing TBI injection on the 110. My only problem is that I'm getting too many Benzes, and I'm not sure my '75 is worth hanging on to. I already put a 4.3L V6 in my '82 300D, which worked out REALLY well, and made a wonderful car that gets great mileage and has plenty of power.
http://www.freewebs.com/rwooldridge/mercedes.htm
Have you considered the 4.3L V6, or do you just want the cubes of the 350? The V6 makes a goodly amount of power, and is thrifty on gas.

BobsterMan · #25 04-04-2006, 08:31 AM

Quote:

Originally Posted by BobsterMan

This elegant debate is more interesting than my 280C with American v8 ponderment. Can the previously otherwise mentioned Mustang II front end solve the problem, or are we looking at the Ford assembly being too light, or is it a MB manhood issue? If I was gonna stuff that beast v12 somewhere, it would have to go mid-engine for center of mass. gravity, and inertia. Sure wouldn't want to enter a wet road under yaw and power with it hanging out the front of a "moped". I'm going with the souped v8 and suspension improvements.

Richard... this "choice" is not exactly as it appears... I was, for the purpose of the thread's author, imaginatively "choosing" from the interests here in this thread. Please toggle over to my post "Newcoming..." for the specifics of my "ponderment"

http://www.peachparts.com/shopforum/showthread.php?t=148793

Roncallo · #26 04-09-2006, 03:01 PM

An M120 engine is on it's way along with the rest of a wrecked 96 SL600. I still need the doner 107 chassie. Anyone have a lead on a 560SL with a good body but blown engine.

John Roncallo

t walgamuth · #27 04-09-2006, 11:06 PM

mind saying what you paid for the wrecked car? pm me if you like.

tom w

iwrock · #28 04-10-2006, 01:38 AM

Yes, how is the interior of the SL600, would you be willing to part with some of the parts if they are the right color?

Roncallo · #29 04-10-2006, 06:20 PM

The car I bought sight unseen as an insurance wreck for $6900. Plus about $1200 shipping from CA to CT and 300 Ridesafely.com fee. It has 46K miles and was hit on the left front. I hope the engine is OK, there does apear to be some damage at least to the intake box on the left side. The car is either blue or black with a grey or blue interior. Everything aft of the firewall looks excellent. Depending on how I evaluate the car, I will either part it out or just borrow the engine and trans for sizing and research for fitment into a 107. If its worth rebuilding I will rebuild it.

I missed on a 97 flood car that appeared to be in a very minimal flood and went for $9900.

J. Roncallo

t walgamuth · #30 04-10-2006, 11:53 PM

i would prob go for a wreck if not too extensive over a flood car.

i find your project very interesting and i will be very interested in hearing about it if you go ahead with it. i understand that rebuilding the wreck probably makes more sense financially, though.

tom w