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Discussion Starter #1
Funny how things come together...

I was just thinking, 'do I really need two sedans?', but the 300D is too rough right now to recoup my money. The RMS is horrifying me with the thought of throwing enough money at the suspension to get it to dance. I really like both cars, both engines. Really, they'd work better for my intents if they swapped hearts.

It's not often that one can do a car-to-car swap like this. I'm moving to NY so it should be easy enough to get away with (could always register it in Florida too). The 300D is smog exempt even without the diesel exemption in NY, and the OM617a running in the Roadmaster would get it registered as a diesel even in Cali without going through a smog ref, so it's not going to be harder in NY.

Think about it: the RMS is great at highway cruising, just being soft and plush and huge, but little else. 108mph is a little nerve wracking, I'll tell you that. Considering it had half the wheelbase or so my CRX was far more confidence inspiring at that speed.

The 300D is a GREAT chassis in a sleeper package that is hampered by a diesel motor that takes thousand of dollars of investment to make truly fast and the least fun automatic ever. It needs a 'real' motor and just price a 400E's fan clutch some time - I can fix the 'expensive' water pump, Optispark and put a new 150 dollar MSD cap and rotor on it for the same price. I might own a Benz, doesn't mean I'm made of money.

Swapping one into the other just makes a whole lot of sense. The RMS can remain stock otherwise and do everything I bought the body itself for easily. The Benz instantly gives me the handling and braking ability I need to not kill myself with the LT1. Late W126 brakes, best calipers I can afford to fit, some heavy duty Bilsteins and a third coil lopped off the front and I'm done, vs something like 700 bucks for upper and lower arms for the B body that still don't exactly tame the rear end.

Also, fitting a stick into a B Body (Caprice/Roadmaster/Impala SS/Fleetwood) is expensive. Like between 2 and 6 grand depending, granted it's fitting a T56 and at that level you're not hacking anything together. But a 240D pedal set is all I need for the 300D to be stick ready, and I already have a Toyota W58 trans that can bolt up to the Chevy with just a junkyard bell. I could keep the 4L60E 'Problematic' and just fab up a way to shift the trans (W123 with a Grant wheel, Goofy Foot gas pedal, and a B&M shifter sticking out of the center console...hmmm....). However I'd rather just have to have the driveshaft altered one time.

The big thing is the oil pan location. The Chevy is easy, Chevy II/Nova pan, done. I'll have to see what the Buick/OM combo will require but I do know that a lot of guys run the 617a in Chevy pickups, so it can't be impossible because they all came with the same 'wrong' set up as every other non-Nova small block.

The W124 chassis would be even better technically, but:

- I don't own one. Hard to beat free.
- W124s stand out as pimpy/drug dealer cars in the wrong areas (like, from the Hudson river to San Bernardino or so); W123s easily get mistaken for Volvo 240's by people who don't care about cars or otherwise know the difference.
- W123 parts are way, way, way cheaper, and the car is old enough to try and not get fisted by a mechanic for supposedly being 'some rich Mercedes drivin' sumbitch'. I paid 800 bucks for a non-freeway tow and a used fuel pump/harness for the sin of driving a 93 Sentra SE-R, breaking down in S. Carolina, and letting slip that I was headed to New York. I honestly almost sent the guy some elbow length exam gloves and a tube of Anal Ease with a not that said 'for the next sucker', but I figured the guy had cost me enough already. A W124 that needs a junkyard part in Iowa? Just hope for that reach around, that's about as good as it's gonna get.
- The W123 chassis is so much simpler to splice a fairly complicated EFI setup from another car into, while there's just more of that crap to deal with on the W124. Come to think of it, the W124 just has more crap to deal with, period. Crap that goes wrong.
- My 300D has that old car vibe that I love. The W124 is old, too, but an old 80's modern, totally different vibe. The 300D just looks like it belongs with a Chevy snorting out twin pipes to me. I always thought of them as like luxo-Checker Cabs from an alternate universe, because most 'foreign' metal doesn't really bear much resemblance to the cars I grew up around. It's just a more natural fit than, say, the same motor in a 5 series, even an old one.
- I already know the W123 pretty much backwards and forwards, especially the car I already own.

It's going to be LONG time before any progress is made on this - assuming I don't just sell the Benz and keep the Buick like I was planning on. However I could use a backup car, I might have a friend who'll drive with me, so we'll see. Until then, I'll just have to delight in crushing the dreams of slow-mobile drivers in a straight line - it's a boat, but it's a fast one! :D
 

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assuming I don't just sell the Benz and keep the Buick like I was planning on.
I'm sorry, I just threw up a little.

Curious though, what is your end goal? Have a reliable driver, or a fast w123, or two cars with LOTS of things that are non standard to fiddle with?

Dave
 

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Discussion Starter #3
The Buick is actually pretty awesome - not a Benz but a comparable S500 or E420 would bankrupt me pretty easily. So would a 4.5 or 5.6 Benz motor swap for the W123 - the LT1 is both cheaper on parts and better on gas (the 4200lb RMS gets 26 on the highway, 17 city - the 450SL only got about 18 highway. Not to mention faster and much, much easier to modify.

Goal is a fast W123 and a reliable, highway cruising, hugiferous Buick that should be able to get 300SD mileage pretty easy. The 300D is never going to get the manual trans, aftermarket fuel pump and turbo it would need to be somewhat of a fun driver; so far all I've seen are Finns with a few extra winter project hours and lots of cash who've done it, stateside seems limited to either wannabes or people with too much money.

The Buick is a 15 second car with stock 2.93 gears and it would weigh about 900 to 1000 lbs more than the W123 with an LT1. The W123/LT1 would be fast enough, even with an auto trans (which makes this swap just stupid easy - I really want a stick but who knows) to the point of, ok, just throw some Bilsteins, W126 brakes, and fat tires at it and call it a day. The Buick is fine, ultra comfy, and would be a good candidate for the OM617 since that's basically a economic cruiser motor. A 300SD was just a tad lighter and did fine with the same engine - and the Buick excels when it's being a 65mph leather sofa.

Although, the thing is, the 300D would be such a weekend car at that point that I might as well just leave the Buick alone and just go with a conventional small block Chevy. The OM617a is so easy to repurpose I could just mothball it until I found something I wanted to run forever. Would be a great motor if I bought my '60 Studebaker Lark back off of my Grandfather. A lot of people thought that old car was an old Mercedes (granted, I don't think they'd ever seen an old Mercedes, but the interior was definitely 'inspired' by the one in the Fintail), and as Studebaker was the original M-B importer in the US, it'd be fitting. And talk about a cruiser - the Buick with blown shocks is like an F1 car next to that thing!

Here's a little write up on the Roadmaster from when it was new. Realize that 200 bucks and a weekend would put some 3.73s in there and according to the folks on the Impala SS forum, such gearing does bring the mileage down - to 24mpg highway. ( Darn.) Also, my car has a limited slip, whereas no W123 did. I'm also looking into installing a Panhard Bar that should tame the rear end, but in reality the car does fine for it's size. Change the tires and remove the speed limiter, the car (just like it's Impala SS/Caprice 9C1 brethren) can run up to 155mph. Say what you will about it's 'Buick-ness' but it's capable of eating Police Interceptors for lunch.

VWVortex.com - The Archive: '94 Buick Roadmaster Limited (LT1)--C/D Oct 1993
 

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Do what makes you happy with your ride, CID. Hell, stick a roots supercharger through your bonnett , whatever :thumbsup:
 

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That is hot..
 

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Discussion Starter #9
I've seen that one, TPI setup. Like a glove :D

I'm thinking of leaning towards the first Gen SBC for the swap, for simple economics - the parts are more plentiful and it's easy to buy some guy's running, built motor for a few hundred bucks if you search around and are patient. Pretty easy to have the LT1 intake machined to accept a standard distributor (better intake than the TPI system) too. There's always a 350, 383, whatever for sale and it's easy to get the car running and driving with a carb and convert it to EFI at a later date.

I had a lot of fun modding my 240D and canyon running with it; really the W123 is a dream chassis for the guy like me who has dreams of a highly capable old American car but broke musician realities. A safe, roomy, classic sedan that can really get down with no expensive modifications. (While I said that the LT1's ills could be fixed for the cost of a 400E's fan clutch, I could fully upgrade the W123's chassis for the cost of just replacing the rear arms on the Buick; fair is fair).

Even most of the people that have owned one don't have a clue as to the potential they were driving around, since they pretty much all came with one boring drivetrain or the other, at least in the states. Mostly it's the almost exclusive choice of automatics that kill the fun.

Add the most swapped motor in automotive history and a solid five speed and you have the power to weight of a Camaro, the solid build quality of Mercedes throughout the chassis and body, a car that can be kept electrically very simple by even 80's standards, common availability of all parts necessary (the only 'custom' bits would be the mounts, driveshaft and exhaust), all wrapped up in a German sports sedan package that's both welcome in any neighborhood yet not so 'upscale' that I'd be confused for some kind of pimpy drug dealer in the sections of town I'm more often found in. Excellent steering, braking, acceleration, ease of repair, reliability and durability, all in a very easy to live with package so if this were my only car, I wouldn't have to make any real sacrifices in getting things done or transporting friends.

Don't get me wrong, I was indeed shopping for a 400E around the same time as the Buick; however the Buick fit my needs (rather than wants) better, and frankly, I forgot the one huge advantage the Buick has over it's contemporary Benz competition; no problematic biodegradable wiring harness insulation. Add a few hundred to the cost of that harness and you could buy an LT1 Buick. ;-)

The Benzes are great but if you want to play, you pay; a fully Benz V8 car would either fall short of my expectations, bankrupt me, or both. However the combined virtues of the Chevy V8 and the W123 chassis should give me the driving pleasure I want without having to compromise speed over handling (or vice versa) or having to simply pay more than I could justify for the privilege.

My 240D put both smiles to faces and hands to grab-handles with under 100hp (well under, most likely I had maybe 80hp and a lot better throttle response after all of my mods), and that was with friends who were used to having money dumped into fast cars. I was fully expecting them to be underwhelmed; picture the same car with multiples of the stock car's power and the ability to 'steer' with the accerator. And still has all of the 'is that a Volvo 240DL sedan?' invisibility unless you want to get all NASCAR with the exhaust tone. And in my quest for my cake and eating it too, use Thrush glasspacks (perf core), 2 per pipe, for both flow and silence; add cutouts in front of the first one and you have a dual mode exhaust that's still legal as you're not running a straight pipe.

While i know I'm certainly not the only guy who's thought of this at all, I'm just kind of surprised that it isn't an 'it' car for the hybrid swap like a 240Z or RX7 or Jaguar is. Granted, the W123 in diesel trim will run forever, sure, but it'll still get it's ass kicked at the stop light by a five year old Kia running the original set of plugs. Yeah, the 350 won't last nearly as long as a OM616, but it can run comparably long to a Benz gas motor and as has been proved a million times over, ANY liquored up redneck can rebuild a Small Block Chevy. If you just read that, you're qualified!

Besides, unlike a lot of projects where the motor swap is just the first and most expensive part of a ton of upgrades (many of them non-standard) or the V8 adds weight, the 617 weighs about as much as an American big-block V8; putting in a small block is either going to be the same weight or lighter. The chassis already has everything you need; remove three coils in the front from stock and attain a near perfect roll center and a car that very much wants to turn. The 15x7s I already have can accomodate up to 275 section width tires, and since the suspension was designed to work those skinny stock balonies to death, such wide meats might not even be necessary.

Really the car just needs the motor swap, Bilsteins, and some junkyard brake upgrading (at least to some decent fluid, pads, and W126 vented rotors), but the handling and braking are already better than pretty much all of the American cars made before 1990 or so (being generous and not really including the Vette or F-Body). Compared to the never ending projects that most swap cars end up being this should be comparably painless, easy to live with, easy to accomplish, and pay out in real, usable performance both in corners and the straights.

Sounds good to me at least.
 

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TPI is ok, but I'd go carb. I'm fighting issues with my 383 Camaro as we speak.
 
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