'74 Westy, diesel conversion

[trevorbrady]

this is my orange '74 Westy Campmobile (non-deluxe), originally from North California and exported to Ireland in 2003.

Since getting it I reinstated all the stuff that was missing, like the original stool and box from between the front seats. I added a headbanger cabinet in the rear and a single-leg cab table too. I sourced a broken dash clock and repaired it, a set of fresh-air "ambulance" fans. The VWoA bumper overriders were on the van when I got it. I found a genuine Westfalia tow bar too. I fitted a 2-ring stove in the empty space in the non-deluxe cabinet and I have the gas tank too but I have yet to fit it and hook up the gas. It still has just the plain old coolbox, no fridge. I also refreshed the rear inner panels with self-adhesive wood-effect vinyl. I reupholstered a pair of Golf2 GTI seats in original Westy orange plaid and fitted them in the cab.

I drove it with it's original 1800 type 4 engine with twin Weber 34ICTs until after Christmas 2009 when I decided enough was enough, 18mpg (imperial, not US!) was just too low to live with. So I ordered a VW inline 4 cylinder adapter plate from KEP and started to gather up the parts required to convert it to diesel.

I had a 1.9 non-turbo engine from a Vento (Jetta3) with a known history and low-ish miles covered so it was the obvious choice for my conversion. I sourced a 091 6-rib transmission from a South-Africa imported van and the fuel tank from a fuel-injected bus, it's got the two outlets in the bottom of the tank.

The first thing to do was to build the engine subframe. I hung an empty case from the transmission and built the subframe around it. I used an empty case and not the fully-laden diesel as it was much lighter and easier to work around. I used the factory engine mounting points in the chassis rails and once it was all built, I removed the middle mount, over the transmission bellhousing.

The engine mounts are stock diesel Vento rear right engine mounts, that's the side of the engine under compression when the torque goes on so I figured they'd be good and squishy for a quiet life inside the van. The diesel would be a lot noisier than the stock type4. The engine subframe is in turn rubber mounted to the chassis too, using stock Vento front cross-member rubber mounts. My reasoning was that if it was doubly-isolated in the Vento, it would have to be the same in the bus. The whole lot, engine and subframe hangs no lower than the original air-cooled sump did so there's loads of ground clearance. The subframe is strong enough to jack the rear end of the bus up with too

I was lucky to have a van with the original type4 engine hatch in the rear shelf. I situated the coolant reservoir as high as I could and within access of the hatch. However, the stock oil filler cap was out of reach under the shelf so I cut a rectangle from the cam cover, flipped it 180 degrees and welded it back in. I now have good access to the filler cap from above

The exhaust is made up from the flexible downpipe of the Vento welded to various bits of the downpipe from a 1.6TD T3/Vanagon and then finally into a diesel Vanagon silencer, rubber mounted to the subframe. The tailpipe had to be cut and welded to make it point in the right direction.

The radiator is a diesel Vanagon item, mounted at a slight angle under the middle of the floor, just ahead of the rear torsion bar. I had to remove the long heating pipe from the middle of the floor to fit it. The connection between the engine and radiator is made using MDPE pipe. It's usually used for cold ground water but is happy to flow hot water too. Due to the positioning of the outlets on the radiator, one of the pipes travels over the torsion bar, the other underneath. Neither are in danger of touching the trailing arm, even on full bounce.

This isn't the final arrangement for the pipes but it's close to how it is now. It give you an idea of how it looks though:

The coolant temperature gauge is a spare I had left over from restoring my old '73 Audi 80/Fox but its origin is immaterial, it's a fairly generic 0-120 degree VDO gauge, which is fine for the engine. I had a bit of head scratching to do when I started the engine up, within about 5 minutes of running, the needle climbed straight off the top end of the scale even though the engine was barely warm. After investigating, the Vento temperature sensor was a 140 degree item so I swapped in a Passat 125 degree sensor. Problem solved. It sits at the 3/4 mark while driving, the fan hasn't come on during normal driving yet. I carefully cut a window into the speedo face and mounted the gauge from behind for a "factory" appearance:

The starter motor is from a B4 Passat TDI, it's a 2kW motor and suited perfectly to the engine. I had a lot of research and trial and error fitting to do to find a starter that would work. The 091 bellhousing is deeper than the other van transmissions so none of the usual aircooled starters would engage the flywheel, even if they could, they probably wouldn't have been able to crank the high-compression diesel engine. I measured up the trans and the motor and made an adapter plate to make the Passat starter fit the 091. The motor has 10 teeth while all the aircooled starters have 9 but TBH, it hasn't been a problem at all.

As for electrics, it was quite simple: a fused live feed straight from the battery to the glow plugs goes through a relay that is switched manually via a push-button from the dash. I know it's not as slick as an automatic glow sequence when you turn on the key but it's simple and works.

There's one extra wire run for the coolant gauge, the live feed to the original coil is diverted to the fuel-cut-off solenoid. The original oil pressure switch wire is used. The original alternator wiring is used but a heavier starter cable has been fitted. There is one extra fused live from the battery to the radiator fan. I was very careful not to chop the original loom about, I have used the original wires where possible and added a couple more.

Once the mechanical conversion was done, I discovered a loud rattle in the van, induced by the different harmonics of the diesel engine. I tracked it down to the rear left side panel vibrating like a drum skin and rattling off the horizontal rib inside the rear side. There was no access to this cavity so I had to swallow hard and drill a hole inside the rear corner cabinet. I stuffed a beetle rear torsion bar bush inside the hole under compression. It pushes on the panel a little, damping the vibration and killing the dreadful rattle.

The throttle cable had to be custom made and was a real stumbling block originally, I used a plain cable, like you'd see on a bicycle brake but because there was a severe 90 degree bend in the run from pedal to injector pump, the cable was binding and the pedal was very stiff and stuck in position. I ordered a new cable in "low friction" sheathing and it solved the problem instantly. The sheath has a nylon liner inside. Job done. I also had to make an extension to the stock pedal lever as the diesel throttle lever has a longer throw than the pedal allowed. I made it with plenty of options to enable fine-tuning but ended up using the last of the holes!

The intention from the start was to preserve the integrity of the bus. It's in such good original shape I didn't want to modify it at all. Except for the nose, all the paint is original '74 German paint and the only rust in the bus was a 3cm hole in the battery tray, a small hole in the rear valance and a couple of pin holes in the windscreen frame, all of which have been repaired now. That hole above is the ONLY modification I've made to the body of the van. Sure, I had to drill a few holes in the chassis rails to mount the radiator but unlike some engine conversions, I haven't cut anything off the van or welded anything to it to complete the conversion. It could be returned to air-cooled power and there would be no trace it was ever converted. Same goes for the wiring loom.

Incidentally, I currently have no heating system in the van. The engine comes so close to the firewall, I had to blank off the coolant take-off port. Once I'm happy that everything is sorted and working well, I'll tackle the heating system. I'm tempted to seek out a diesel Eberspacher and fit that. We'll see...

So it's running and driving now, what's left to do? I just bought a sheet of steel today to build a shallow duct ahead of the radiator to allow it to draw air from between the front wheels, not behind them. I want to protect it from debris kicked up by the wheels. It will also close off the sides of the radiator, ensuring any air above it can only pass through it, not around it. There's a small weep of oil from the cam cover but that's hopefully an easy fix. I have a few miles up on it by now and it's cooling itself nicely even without the sides of the radiator closed off. The fan hasn't cut in yet.

Let me know what you think, I know the stock nazis will freak out but bear in mind the fabric of the van itself hasn't been modified. All changes are reversible with minimal work. I'm very happy with how it has turned out. I'm curious to see what MPG it's going to get but it'll be a while before I put up enough miles to find out. Incidentally, all the work, from mechanical, electrical, bodywork, upholstery, machining etc is all from my own fair hands. I'm a DIY kinda guy

[busdaddy]

[Krautski]

[trevorbrady]

[Sloride]

Well done Trevor. I remember watching your build on vwkd. With all the conversions threads I guess I better get mine on here too.

Craig
_________________
1972 Westfalia - 1.8 VW in-line h2o conversion
Ottawa, Ontario, Canada

Link to the engine swap:
http://www.thesamba.com/vw/forum/viewtopic.php?t=565304&highlight=

1964 Ruby Red Beetle

https://www.thesamba.com/vw/forum/viewtopic.php?t=705757&highlight=ruby+red

[CoastalAirCooledVW]

Nice install, diesels are badass. I would be a little dissapointed with the performance though if I just spend all that time on it and you are cruising slower than if you had the original engine I would throw the biggest set of tires on it that you can find. Do you have a tachometer?
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1966 Velvet Green Standard

[trevorbrady]

yeah, if I can get the cruising speed up a little I'll be much happier. TBH, if I can get better than 18MPG the conversion will be a success. I know it's kinda stupid putting in months of work and a ton of cash into project that aims to save a few pennies on fuel but it's something that I always wanted to do, it's amazing VW never put a diesel engine in the bay window bus, the Golf and Passat diesel engine was available from the mid- '70s onwards.

[CoastalAirCooledVW]

Is diesel cheaper or more expensive than gas (petrol?) in Ireland?
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1966 Velvet Green Standard

[webwalker]

Since the diesel is going to have a considerably different torque curve than the Type4, not to mention top out for RPMs at a different rate, it was almost a given that you would need a different set of gears in the 091, regardless.

If you're topped out at 50-60mph, you've probably got lots of torque that is going unused because of the ratios.

I love the idea of dropping a diesel in, chiefly because a Bulli could you the extra grunt at the bottom end, and would make a lot better use of the extremes of mileage that a diesel is capable of. Most of all, a bulli driver is already used to a dead slow acceleration, as long as he gets to his cruising speed.
_________________
"Consistent maintenance with quality products is the cheapest warranty you'll ever need."
1977 CE1 Transporter Deluxe, Subaru EJ22, Skills Cooling, Steedle HD 091 w/ GuardT .82 4th
Click to view image

[trevorbrady]

@CoastalAirCooledVW:

diesel is about 8-9% cheaper than petrol here at the moment but the gap is closing all the time. In the UK, I believe diesel is more expensive than petrol.

@webwalker:

I upgraded from the 1800 3-rib "pyramid" transmission that was in the bus to the 091 2-litre 6-rib trans for the improved ratios. If after a while I decide that it really needs a 5-speed to release the potential (highly likely TBH) I'll be going with the flipped Passat transmission.

[markd89]

Looks cool

I have a TDI in mine. If you get a 0.70 4th gear you'll drop your RPMs at cruise and be able to go faster than 50.

You'll have to do the math on what's optimal and make sure you have enough power to turn the gears at whatever RPM you like.

My TDI gets buzzy at 3500 RPM. I'm usually driving 3000 RPMs +/- 500 on the highway. I can do 80+ MPH but don't do that much

Mark

[trevorbrady]

well I'm glad to report my cigarette-packet fluid dynamics experiment is a success!! I finished the ducting tonight and took it for a "spirited" 20 mile jaunt including up and down that big hill near me in both directions. The temperature needle sits just below the halfway mark for flat driving at 90kph and rose to just over halfway towards the top of the hill while maintaining the same speed. Result!!

There is a small bit of fluttering noise from the leading edge of the duct but a fold along the edge will stiffen it up and remove the flutter. A small modification thankfully. I'm really thrilled it's working as it was all very "seat of the pants" engineering.

here are some pics for reference:

the lowest point on the duct is the lip on the rearmost section, it's 5.5" off the ground. The main part of the duct is 7.5" clear. Part of my drive was over a set of speedhumps. No scraping!

one thing I did notice due to my "spirited" drive was that the clutch will slip between 2nd and 3rd or 3rd and 4th if I get on the throttle too soon. The clutch kit is the standard 1800 air-cooled type and is no more than 2000 miles old. Evidently it's too small for the torque of the diesel engine. I'll have to research a solution and just take it easy in the meantime.

[Stuartzickefoose]

Updates ?

Mpg?


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Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[vwwestyman]

LOL Stewart! I'm surprised I never saw this thread initially, but somehow I knew you'd post asking about MPGs!

If I was brave enough to add up all the costs I put into my conversion, I'm sure it would take driving a zillion miles to justify the cost in fuel savings.

For me, it is the extra power, the fun of having build something different, and being able to hit the cruise control button and just go.

For the OP, if you're still around, I'm curious what you ended up doing with the transmission? Regear? flipped Passat?

Also, I really like that carrier bar you build.

I think one is wise to incorporate the costs of a rebuild/regear when calculating/saving for such a conversion.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[Stuartzickefoose]

I found it looking for ambulance fan stuff and was surprised I missed it too!

I told you it's about range not cost....driving between towns world wid it can be a big difference...hell Alaska is a great example too. 200 miles a tank doesn't cut it!
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Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[vwwestyman]

[Stuartzickefoose]

But if I increase range AND have jerry cans I'll go that much further
_________________
Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

206-841-7324
[email protected]

[tristessa]

[trevorbrady]

thanks for your interest guys. I haven't been back on thesamba much lately.

regarding MPG, I'm a bit of a geek when it comes to keeping track of the fuel economy. I've found fuelly.com to be really useful. See the stats for my diesel conversion here. Bear in mind, I have it set to measure in UK gallons, not US gallons:

http://www.fuelly.com/car/volkswagen/kombi/1974/trevorbrady/218403

the average MPG (UK) is 34.5 with a best tank MPG of 41.3MPG. I use the van a lot for towing my mk1 Jetta TDI race car so the MPG has been hurting of late!

Incidentally, I now have almost 10,000 miles done on the diesel conversion and I'm happy to say, there has been almost no maintenance required. I replaced the water pump after about 2000 miles as it had started to drip a little and that's the warning sign of impending doom. I should have changed it before I put the engine in, really. It's coming up to its first service now too. Other than that, all I've done is drive it!

re the heating, I never did anything about it!! I just lived without on the couple of winter drives I had to do. It's a 95% fair-weather van so it wasn't a major issue.

re gearing, I've been collecting up all the bits I need to do a TDI and flipped Passat/A4 transmission conversion. I have the gearbox already converted to run upside-down and the engine has been sourced: I picked up two AFN 110BHP engines a couple of months back. I've replaced the timing belt kit, water pump, filters etc on the freshest of the pair and it'll be going into the van as soon as I get a few more jobs on the Jetta out of the way. I plan on gutting all of the current conversion and basically starting again. None of the engine subframe, exhaust etc will be useful as the engine will be mounted a bit lower than it is at the moment. This is necessitated by the flipped transmission. Watch this space for details on the TDI upgrade.

[vwwestyman]

I'm interested to hear of your thoughts on the flipped Passat transmission. I know one guy working on it in a Bay and he said he has had more work to convert than he was originally expecting.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing