TDI install retrospective: Physical Mounting

Continuing the process of back-documenting what I did to put a TDI engine into an old (1972) air-cooled VW bus. Today I cover physically attaching the engine to the bus. This may sound simple, and if you only saw the end result, you might still think so. That's the beauty of what Hal built. Elegant in it's simplicity.

Transaxle Mounts

early mount attempts

The stock bus has three mount locations for the engine/transaxle combo: the front of the transaxle, the bell-housing in the middle and the "mustache bar" near the rear. I decided to reuse the transaxle mounts without modification. The transaxle wasn't really getting modified, so it should just fit. And it did. There were some who questioned the vibration through the mounts at the bell-housing, though. I believe there have been experiments by others where the bell-housing mount was eliminated, but I have also heard that this put stress on the output shaft and other components because all of the weight was being handled on the ends. Looking at the front-most transaxle mount, I'm not sure it really should hold up more weight than it was originally designed to hold. Your bus; your choice. Now, years later, I am fairly convinced that the bell-housing mount holds most of the weight of both the transaxle and the engine.

Motor Mount Attempts

bar to rear frame, 1st model

I looked at and tried a few different things to mount the engine. First, we tried building mounts that would attach to the sides of the engine to threaded bolt holes that were unused in the stock vehicle install. These bolt holes were on the block for industrial applications of the engine so, they should have been stout enough to do the deed. The idea was to reuse the original bolt holes for the mustache bar. The holes in the block and the mustache bar didn't line up very well and since the plan didn't include anything to absorb vibration, the bus would have shook like a paint mixer. I tried to accommodate this issue with some vulcanized rubber mounts, but it looked complicated and not terribly strong. So, I threw the whole thing out, and got to talking with Hal about it.

box being developed

Hal knows bus. He recognized that the rear bumper brackets are held to the bus with thick carriage bolts to the rear frame. The same rear frame that the mustache bar attached to, just more rearward. We figured that if we leveraged the mustache bar concept with a thick, straight bar between the bumper brackets, we could re-use the stock TDI passenger-side motor mount. To the right, here, you can see an earlier version. Hal and I agreed that something less complex would work.

Motor Mounts
Seeking something simple, we started with a piece of 1" angle-iron, onto which we marked and drilled holes to align with the bumper bracket holes. The bracket was then bolted to the rear frame so a straight bar could be measured, cut and welded on. Bar done.

Then, Hal welded together a simple box with a central support that would join the mount to the straight bar with bolts. The whole thing bolts together: the bar to the frame (re-using the bumper bracket bolts), the bar to the box (with a basic bolt-nut pair) and the box to the mount (again with a basic bolt-nut pair).

I have removed and re-installed the engine both with and without the transmission numerous times. This part of the system is a total non-factor in the process. I have also removed the rear bumper a few times independently of the motor mount, and while it is slightly more difficult than before, it is not really impacted: I simply support the bar with a floor jack, remove the 4 bolts (2 per side), remove the bumper, put the bolts back in and lower away the jack. Super simple. Of the things that were done for me for this build, this is the single greatest contribution. I said it then, but haven't said it enough since: THANK YOU, Hal. You really crushed it.

Measurements of the straight / cross bar:
length of main span, from bracket to bracket: 42"
angle-iron "bracket" depth (front-to-rear): 6"

Measurements of the box:
across the top: 9"
height: 7.75"
space between vertical bars: 3"

Prior related posts:
Preparation
Fuel System

Next related posts:
Vacuum System
Air, Intercooler and Exhaust
Primary Electrical
Cooling
Secondary Electrical
ECU, dashpod and Sensors

it moves, its loud, but it moves!

Progress, progress. With an appointment at Meineke to build out an exhaust system set for today, I had a little extra motivation. Knowing everything was "good" according to my trusted mechanic friend, Justin, I moved quickly and confidently. I'll hit the highlights today, though there will definitely be more tomorrow.

Battery
Last night, I stopped at Batteries Plus and bought a replacement battery. With the instant discount and the mail-in rebate, it'll cost around $65 for a Group 40 (or is it 48?) Rayovac battery. I hadn't heard of Rayovak batteries since the old "I dare you to knock this battery off my shoulder" advertising. Apparently, they're deep into automotive batteries now. Anyway, I called them yesterday morning, and verified they had one, I picked it up and installed it last night after the kids were fed. I fired up the engine, grabbed T and backed the bus out of his hiding place into the driveway. There was much rejoicing.

Test Drive
T hopped into the passenger seat, and we tried to take a little spin around the neighborhood. We noticed a few things. First, an un-mufflered diesel engine is still really bloddy loud even if there is a turbo absorbing some of the noise. Second, while the engine was cold, the bus shook like a mother. After about 30 seconds it settled down. The clutch made all kinds of noise, and finding the gears was a challenge. I think I have some shifter adjusting I need to do. Reverse is easy to find, but I can't find first, so there's something batty happening there. Regardless, we drove around our little circle and around the neighbors little circle (cul-de-sac's) and pulled into the driveway. Our little test was over, but it totally passed.

Belly Pan, Clutch Cable Tightening
Before I could drive it to the muffler shop, though I had a couple of things I needed to do. First, I had to put the kids to bed, feed the animals, etc. Next, the belly pan that lives under the pedals needed to be re-installed. This keeps the weather from getting in there, which is especially important with the placement of the brake switch and the accelerator pedal switch. With the wet weather we've been having, we wouldn't want a puddle-splash to fritz the switches. I couldn't find the original bolts, but I found a handful of stainless 10mm bolts that fit. Last, the clutch cable needed adjusting. Now, the cable itself was relatively new before the project started, so it probably isn't fully warn-in. The clutch and pressure plate are brand new, so they will take some seasoning too. I expect to be performing some level of cable adjustment for the next few months accordingly. It had gotten to be about 9:30, so I called it good.

Drive to Meineke
My appointment was at 7:30, T needed to leave for school at 7 and C needed to leave for school at 8:45 (with a parent wake-up at 8). I am the only adult in the house, and I hadn't a ride home from the muffler shop. So, I woke before 6, with a funny plan for getting everything to align. First, I grabbed one of the kid's bikes and tossed it into the bus. I like bus-traveling with a bike anyway - its like a lifeboat. In case of trouble, you can pedal to a parts store from a roadside breakdown much faster and farther than on foot. Anyway, I pulled out of the driveway, and drove to the shop, using 2nd and 3rd gears all the way. Without the benefit of a tachometer, and not being familiar with the sound of an un-mufflered diesel engine, it wasn't easy guestimating the shift points. I relied on some common sense, though, figuring my shifts should come earlier than in the old pancake engine, and knowing that the accelerator only went to 78% meant I couldn't really get the RPM's into redline.
I arrived at Meineke as the defroster was starting to produce some warmth. I topped off the brake fluid (remember, I had it open to change the rubber lines earlier), pulled the bike out and rode home. I arrived home by 6:35, so I had time to prep for the day. T ended up staying home from school sick with that phflemmy coff thing that's gonig around, but I dashed back to the muffler shop to hand off the keys and talk about the project with the manager. "I want it quiet," I said. He accepted the keys nad I drove home to get C up for school. Again, I was ahead of schedule, and could enjoy some coffee before wrestling him out of bed. He got ready, ate and split for school (taking the lunch I made for him ) and I hit the road for work. I've spoken to Meineke from work, and the exhaust is done, with a lifetime warranty. Sweet. I'll drive it home, and post an update in the next couple of days about how it ran, sounded, etc.

It is hard to believe I'm actually at this point. There have been a couple of wrenchers without whom this would not have been possible. Hal and Justin, your assistance has been immeasurable and so, so greatly appreciated. I want both of you to sign the partition behind the passenger seat that's exposed to the main open area so your names will forever be connected with what we've done. There is time tomorrow to talk about what the next steps are, etc. For today, we smile. And nod. And bask in the gravity of the achievement we accomplished. Today, we have a 1972 VW camperbus getting pushed down the road by a 1998 NewBeetle 1.9 liter TDI engine.

pictures:
top - Justin fooling with the low-pressure return lines (we replaced them on Sunday)
middle - Hap's parking spot for nearly 2 years, now vacant (rain)
bottom - in the driveway, ready to go get an exhaust (rain)

Battery of Tests

Well, its been too long since my last post, but I didn't want to post anything until I got a breakthrough. Unfortunately, I haven't had one, but I figured I'd left the blog out in the cold too long. Speaking of "out in the cold"... the weather has been a regular topic in this blog, and in conversations with fellow Pacific North-westerners all Summer. Now that Fall is officially here, most folks are expecting the rains to set in. My wife and a few of her friends are trying to stay optimistic, but I'm not betting on any more warm, dry days. This makes for a very unpleasant effort on the bus project, exacerbating my current frustrations.

Feeling Fuelly
After getting the engine to run for a few seconds here and there, I thought my troubles were to be quickly resolved. I felt that if I could get the air bubbles out of the fuel system, I could get the engine to run reliably. I moved the large stock fuel filter operation from where Hal had installed it (you can see the mount holes in the top picture there), up to near the top-hatch (see bottom picture). I figured part of the problem was that the Injection Pump was the high point of the system, so air bubbles were getting trapped in the pump. I checked my Jetta and noticed that the fuel filter was right next to the coolant bottle, so I thought, "maybe the height matters". There's a picture here to the right. I don't know if it does at this point, because the engine still doesn't start. I pulled the clear filter I put in between the tank and the stick filter as well. I thought maybe this was allowing air in, or at least giving it a place to collect. This didn't help either.

Battery of testing
With all of the attempts to start the engine, the battery keeps running down. I find that the quick 10Amp charge doesn't actually work, and I need to charge the battery on the slower 2Amp cycle. This introduces a considerable amount of lag between starts. As I write this, the battery is getting charged again. I have noticed that the primary cable running from the battery to the starter gets warm at one of the splices. I am a little concerned about that. Of course, the engine should start quite quickly under most conditions, and little current runs through there other than to start the engine.

My latest attempts have been surrounding the fuel supply again. I have routed the return line from the injection pump to a jar that's 1/2 full of diesel. As the engine start attempts are run, I can watch the fuel level move up and down, as well as watch the air bubbles appear. I'm hoping this is helping to bleed the air out. The port on the fuel filter that the return line connects to has been closed off, so no new source of air is introduced. I have not had much luck with this arrangement yet. I am starting to worry that I messed something up the last time I had it running and it got a little rough-sounding. To me, it sounded like it was running out of fuel, so I shut it off. Maybe something more worrisome happened. :(

That's it for now. If you have any ideas for why its not catching, I'd love your input. They say insanity is repeating an action with a different result expectation. With that, I'll keep trying to start this thing while trying to think of what could be the cause other than air in the fuel system.

Pictures:
top - where the fuel filter was mounted before. Note the clear plastic filter has some air in it.
middle - fuel filter in the Jetta.
bottom - new fuel filter location to mimic the height of the filter in the Jetta

Findings

I have learned a few things about the next steps on the electrical from my thread on TDIClub. I wanted to post these findings so I don't lose them (and so everything is in one place). First, I wanted to send a congratulations to Hal. Over the past few months, while I have been slowly tryingto get my bus together, he has installed a water-cooled gasser engine (VW straight 4) into his bus. This was a simpler install, but he still had many of the same challenges: radiator placement, adapter plate, some clearance issues, etc). I got an email from him the other day tellnig me that he test-started his engine. He hasn't been able to test-drive it yet, but he is very close. So, congratulations, Hal. I'm proud of ya, and you're inspiring me to keep going.

Firing the Starter
I mentioned in my last post that I extended the wire that runs from the main harness to the starter. This wire is set to 12V by the computer (ECU) when the "X" circuit is powered. This was the case on the old bus just as it is on the NewBeetle. I guess some things never change. Anyway, I need to notify the ECU that "X" needs to be powered. To facilitate this, I extended a wire from near the starter (where the original "X" wire terminates) to the ECU. This wire needs to power a pin, or somewhere in the ignition plug. I'll piece that together tomorrow.

Trigger "run" to computer (ECU)
Somehow the ECU needs to know that the main switched power has been activated. Most of the electrical system is turned on or running when the ignition switch is at this point. On the old bus, having the switch here allowed the heater blower to turn on, the windshield wipers to work and the exterior lighting. That's it. Talk about old-skool simple. With the computer system controlling everything, this is one of the more important things to communicate into the box. Like the "X", this wire needs to power a pin, or somewhere in the ignition plug.

I have taped-up a 3-wire bundle that will send this signal down to the computer on one wire, and the 12V state of the next 2 sections below on the other 2 wires. Unlike the rest of the wire bundles, this one will run inside the bus along the drivers side of the body from by the clutch pedal to the westy closet where the ECU is hiding.

Check Engine Light (CEL)
Probably the most important indicator light on the TDI engine is the Check Engine Light. This light illuminates whenever any code is thrown by the computer (ECU). In order to run safely, you need this light operational. I will be installing a small LED inside the stock bus dashpod so it is visible while driving. To power the LED, one side needs to be connected to "circuit 15" (aka switched power) which is 12V when the ignition switch is turned to "run". The other side of the LED needs to be connected to pin #43 on the ECU. When the ECU throws a code, pin 43 is grounded, lighting the LED. Otherwise, the pin is set to 12V.

Glow Plug Light
Second in importance only to the CEL, is the glow plug light. This light tells the driver when the glow plugs have satisfactorily warmed the combustion chambers. If there is a problem in the glow plug circuit, the light flashes. Next to the CEL, I will be installing an LED for this. Like the CEL, one side is powered from the switched power (15) for 12V. The other side of the LED needs to be connected to pin #41. Like the CEL, the computer (ECU) grounds the pin to send a signal, and sends 12V to turn it off.

Tomorrow is Friday which means it is early-release day. Hurrah! I should be able to get the wire bundle in and wired up. I need a pair of LED holders, and I'll have to pull the dashpod to make holes for the 2 LED's, but I'll probably wait on that until I've confirmed that the wiring works. That's it for today. Again, congrat's to Hal for getting his engine started. I hope to hear of a test drive one day very soon.