What direction to take with this car?

Backstory:

Back in 2013 my friends and I bought a 1979 300SD and built it into the Planet Express which we campaigned in LeMons for many years. She was very good to us, delivering an IOE and a class C win. The old girl is slow, steady, reliable and handles surprisingly well for a 1970s full size luxury car. In the fall of 2016, the fire nation attacked. We had an A&D from the Dirty Little Freaks in oregon and while she was in the car something(we now think a clogged radiator) went wrong. She slowed down and came off track went the temp increased, but the damage was done. There was no water left in the radiator and the gauge said 230°F. The oil was cooked and was effectively sludge. We flushed the rad, changed the oil and went back out, but she was still overheating on an easy lap. Oh well, thankfully we were also running our 300D that weekend so everybody got to get on track and I talked my way into a fast car for a few laps. After that race it was decide that Planet Express would go to me(it was always my baby) and the team would focus on developing the Toyocedes.

So now I have Planet Express. It's got a questionable engine, full cage, refreshed stock suspension and needs paint. Since that time, it has also decided that it doesn't like starting(glow plugs? compression?), doesn't charge very strong and has one brake caliper that is stuck. In 3 years I've actually driven it about 250 miles(before the caliper stuck) including DDing it while my BMW was down for paint.

Where I'm at:

Since taking ownership my life has changed. I now live/work in California for 5 months and North Carolina the other 6(there's some travel time). I lost my lovely garage/storage unit to a landlord who no longer allows car work. My off season car and PlanEx live in a storage unit currently, an hour from where I live, with all my tools and my off season clothes. I am at least working on making that better. Where I live I've got a sand driveway, minimal tools and a small amount of indoor space, albeit 5' above the ground because this is a very flood affected area.

Where to go from here:

This is where I come to a standstill. I saved up money to work on PlanEx. I have plenty of time right now to do lots of work. I want to have a kind of "plan" that I can work towards right now. I just don't know what makes sense. My other two cars are my winter and summer DD. They make sense: one is efficient and 4x4 while the other is my fun summer dream car.

In the back of my mind I want to race PlanEx again. I would love to get it fixed up, souped up and bring it to a race and invite my team to run with me again. One teammate has mentioned cutting the cage out and reinstalling an interior. Not enough creature comforts remain/work to make that possible in my eyes. Plus, it wouldn't do anything that the Jeep/BMW don't already do. I've also breifly thought of putting stiff springs back in the rear and a trailer hitch. Or do I just say screw it and make it a fun cruiser? But like I said, my BMW already does that pretty well.

Then it comes down to powering the thing. I wouldn't mind making it faster. I see no point in installing another 110bhp 5cyl OM617. It ran the 1/4 in 19.6 at 67mph. A drag calculator said that's about 85whp which sounds right to me. There's the option of a newer MB diesel like an OM602/3 or OM606. Those can make some decent power, but they're becoming a bit harder to find and making HP with them is still a little pricey. Plus, adapting a good manual isn't super cheap or easy and I would really like to give this car a 3rd pedal. I've drempt of a VW TDI swap. That can make 150whp with relative ease, take 150lbs off the front of the car and there are adapters to many common transmissions. Or there's silly options, if I wanted to make it a tow pig like squeezing a 6.5TD in there(it would fit, barely) but I see that as less realistic. But I'd love to hear other ideas.

Help me Obi One, you're my only hope:
I mean, not my "only" hope, but I'd love to hear from other guys who have experience with project cars and what they might do in a similar situation. I would love a reliable, fun, 150+whp, diesel, manual W116.

My thought is this; you had a blast with the car as it was, why not just find another clapper Merc, stick a fresh/replacement engine in it and have some more fun?

I'm with Tom, poke the easy button for getting her under her own power. Look for upgrades after that. With living in two places, a car that moves itself will be a happier project.

Putting another 617 in it doesn't really excite me. It was fun to blast around at 85whp in a 3250lbs tank when I was first getting into racing but part of my thing is that competitive me wants to be faster than the new racecar.

I've thought a little about putting in another 617 and adding go-fast-bits, but it's a difficult engine to make power with and a difficult engine to manual swap, which is even more important to me.

Ls swap it. A 5.3 truck engine. Seems like the simple solution, reliable, inexpensive and a lot faster and probably lighter. 

Dusterbd13-michael said:

Ls swap it. A 5.3 truck engine. Seems like the simple solution, reliable, inexpensive and a lot faster and probably lighter. 

agree. you wont even need the 3rd pedal. but the LS option is a lot like a c5 corvette. Its absolutely the cheapest way to go REALLY fast, but there's no imagination and the interior sucks.

If it must stay diesel, what about a turbo american truck? 6bt is probably too much "2jz" tax, but I'd think that the ford or chevy options should be findable for reasonable prices with attached manual transmissions.

Buy a wrecked mustang and go 5.0/t5?

Does it have working reverse? Assuming that it does, you have two options: Forward, or backward. If you go backward, ask Mater to help on how to use the mirrors. 

SBF or SBC would be easy buttons, yes, but one of the only things I really want is that it stays diesel, manual would be a huge plus. I don't mind racing an auto, but I'd rather not, and I really don't like it on the street. Strangely, the worse the auto is, the more okay I am with it and the current one really sucks.

I am a huge OM606 fanboi, but I have a feeling if you go that route you won't be racing Lemons or Challenge with it.  They are selling for unobtainium prices.  I think your only hope would be to find an insurance car 98-99 W210 for $500 that had the back end taken off by a train.  Otherwise, a good 606 on a pallet is going for $1200 as a long block in some cases.  If you're just making a driver and don't want to race it, (by that, I mean race in the cheaper classes like Lemons or challenge) this is my first choice.  Hard to adapt a manual to it, but there are some Jeeps that can help you there.  The VM Motori diesel in the Liberty got (I think) a mercedes 6-speed.  Same goes for the Sprinters.  They aren't what I would call reliable, but daily driving should be no issue.

The TDI swap is pretty simple.  I've never done it in anything, but it's tiny, easy to modify, and makes decent power in the right hands.  Keep in mind, because it's tiny, that you can't go nuts with it.  Whereas with something like an OM606 cranked up to 11 means 400hp/650tq on a stock lower end, a TDI cranked up to 11 looks more like 200hp/300tq before you start bending rods and blowing head gaskets.  If you're interested in TDIs, go hit up some Ford Ranger folks.  There are several TDI swaps in Rangers out there.  There is a relatively inexpensive adapter that converts to a chevy pattern, so things like an NV3550 will bolt right up.  The only reason I don't have one in my Ranger is because I use my truck like a truck.  I tow a lot, and I didn't want to have to turn a TDI up to 11 and hope an NV3550 would take the torque and the weight.  I would rather have something in the 3.0L range that's turned up to 4.

I'm also a bit of a fanboi for 6.5TDs, but they are big and heavy.  Having owned at least one of every truck diesel out there (except for only one post-DPF starting in 2008), The 6.5 is one of my faves.  They score great in the NVH category, they are as reliable as dirt, easy to chip for more power, and far more torquey than the numbers suggest.  You won't need to chip it at all.  Don't focus on the 190hp number, you'll be smearing tires like they were pencil erasers.  My big concern is weight.  They are 800 lbs or more.

I have been in this conundrum for years.  The options for mid-size diesels are very slim unless you look to the most recent Ecodiesels and mini duramaxes.  They're not only selling for $4000 used, but they are so complex.  I want a 3.0-4.0L ish diesel that can make some oomph by turning up the dial just a bit and get 250hp/350tq.  That isn't easy.  The commercial world has some options; UD, Isuzu, 4BT etc, but they are supremely low on the NVH desirability category.

If I were going gas in that car, I might consider an Atlas from a Trailblazer/Envoy/Colorado.  Reliable, torquey, I-6 so it should give you the least number of fits getting it in there.  Lighter than a 5.3L, but not by much.

Just thought of something...

Olds 350 diesel?  Don't laugh.  They were absolute junk in stock form for two main reasons; 5 head bolts that they scavenged from the gas parts bin, and TSB repair procedures.  The weak head bolts allowed head gasket leaks, and the TSB just said to put new gaskets on and re-use the same bolts.  Swapping to good 1/2" studs and steel shim gaskets fixes them and makes them reliable.  I knew a guy with one in an old boxy S10 making 300 hp and I forget torque, but likely in the 450 range.

Come to think of it... maybe I could do a 4.3L Olds V6 diesel in the Ranger.

They sell cheap.

We've got an OM606 with an OM603 pump in the Toyocedes. The Lemons Judges penalized us accordingly but we love it. It cost us about $2500 all said and done for buying a W210, swap parts, transmission and selling what we could. There is a BMW transmission adapter available, and I do love the BMW ZF320.

I've thought a lot about the TDI. I like the size, age and adaptability. My friend has a 911 with an ALH and has been bugging me to TDI PlanEx. That's why it's near the top of my list.

My old boss is a 6.5TD guy. He has a rental fleet of 9 GMT400s, many of which are over 250k. Pretty sure he even has a few spares laying around. It would make PlanEx less viable as a road racer but it would make good power, make good noises and probably be fine for towing a small trailer, which would be cool.

The older cummins engines won't fit in any way. They're too tall to fit under the hood and a 6bt wouldn't fit in the engine bay without firewall surgery. A german version of Cleetus's car would be rad though.

Too bad nobody other than Mercedes has a 3ish liter diesel in the US that is relatively easily swappable. If the OM648 was easier, I'd be looking at it.

There are also plenty of TDIs to choose from up to V10s (wallet prohibitive).

buzzboy said:

Too bad nobody other than Mercedes has a 3ish liter diesel in the US that is relatively easily swappable. If the OM648 was easier, I'd be looking at it.

Truth.  Hardcore truth.