Radiator Placement on a 1971 Conversion to 1.6 TD Engine

[avocado_tom]

I know it's been done before - converting Bays to water-cooled engines - but I was reading some of the other posts on radiator placement and I wanted to share some thoughts and hear other people's ideas.

I am about 80-90% done in converting my 1971 bus to a turbo diesel engine. The big thing about moving to water-cooled (obviously) is the radiator placement.

My biggest criteria for the conversion has been: I still want to be able to off-road and not risk loosing a radiator or a hose. This means I want my water lines protected and I don't want to loose ground clearance.

The problem with the '71 (as opposed to late bays) is that there are no holes in the frame rails to route 1.25" water hoses through. This means hoses going forward have to hang below the rails somehow. This may not be an issue - use strong pipes, make a cage around them, whatever - and you can feel good that they're going to be ok, and you're probably not losing much ground clearance.

But I wanted to avoid this - at least at first - so I put my radiator in my engine compartment. It may move later, but what I've found is that the rad from the '84 jetta I pulled the engine from just barely fits in the engine compartment. I have to see how much the fan is cycling - I'm going to install an indicator light - but for the time being it runs around town. If I get into any kind of spirited driving or prolonged hill climbing, however, it overheats.

Engine and Radiator, Installed

My temporary solution to this was to:

1. put a shroud on the back of the radiator to direct air downwards out of the engine compartment (probably doesn't help on the overheating but a good idea regardless) (you can see this in the picture above)

2. install an aux radiator in the belly, fitted with a scoop.

Why an "aux radiator"? Well, it's actually a Ford heater core and it uses the same diameter hose as my heater which is mounted in the belly (I lose about 1 1/2" to 2" of ground clearance at one point of the belly). And, the bonus is that the heater lines are only 5/8" Diameter and fit in the old heater ducting, so they're protected.

Aux Radiator Shroud/Belly Pan/Scoop 1

Aux Radiator Shroud/Belly Pan/Scoop 2

Heater in the Belly with protected lines

Belly Heater and Aux Radiator in situ

This "aux radiator" mounted downstream of the heater has seemed to take the edge off my water temperatures enough to allow me to drive in a more spirited fashion, although further testing is going to have to wait until I solve a low oil pressure problem with the engine that has cropped up again (a problem which I knew existed before I started the conversion).

I may move the radiator at some point, but I'm not quite there yet.

One other point of concern in doing that is keeping the head cool. Some info here posits that you want to have some sort of drum above the head height to keep the water flood high enough:
http://translate.google.com/translate?hl=en&sl...agina1.htm

This makes sense to me, but could be accomplished with a large (3 liter is suggested) coolant overflow drum. This could be mounted where I already have my coolant overflow or just bolted somewhere in the engine compartment.

Coolant overflow bottle

Thoughts? I liked what leadvillerpm did here: http://www.thesamba.com/vw/forum/viewtopic.php?t=4...p;start=80 and I know bluto has had good luck with his belly mounted rads (http://motorheads.net/vw/turbobus/page7.html) but as I said, I'm leery of losing ground clearance.

Some more tidbits on my conversion are here: http://www.vwdieselparts.com/forum/viewtopic.php?f=20&t=10174
And not enough pics are here:
http://www.flickr.com/photos/avocado_tom/sets/72157624446779933/with/5916472127/

[Steve46038]

I dont really know, but I think I saw a bus with a Pontiac Fiero radiator mounted on the roof in VW Bus Custom Handbook (Motorbooks Workshop) [Paperback] by Laurence Meredith.

Your list of requirements almost corners you into roof-mounted cooling.

However...I remember a Lexus concept car that ran rear radiators...I wonder if a rear-engine-hatch mounted radiator sucking air from the D-pillars with the assistance from some electric bigassfans could cool the beast???

If you wanna offroad, may I suggest a Cherokee like mine? Its damn near unstoppable...
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1978 Westy
1997 Jeep Cherokee 4x4
2008 Infiniti G37S 6MT

[SGKent]

if you are going to off road, on the roof mounted in a cage for protection against low branches or on the front with bars built around it. Underneath would look prettier but getting high centered on a rock will leave you with more problems than just a high center. Less mud on it too.
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"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[78Kombi]

Im with Steve. Pat Cook (cooknbus) cut out the center of the rear engine lid and mounted the radiator there.. Clean and close to the engine. You are over engineering if you are trying to get the radiator in the front.
Joe
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78 hightop 2.0 FI

[chazz79]

My bus will eventually end up baja styled like fastmc's. I built my radiator set up with this in mind and feel it's well protected in the belly of my bus. I'll get it 2 inches higher and toss some 235/75/15's under it and have all the clearance in the world for the log/fire roads I plan on hitting.

I have tried the side mount radiators, the airflow just isn't there. You're pulling heat off the engine via water transfer then re-bathing the engine in the heat you just removed. It's counter productive. They never designed that box back there to flow air without a fan spinning. It's just an oven you get to engineer around.
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One day as a lion, or a lifetime as lamb

The green monster in bits and peices: http://www.thesamba.com/vw/forum/viewtopic.php?t=332556&highlight=green+monster

[RatCamper]

OP, let me ask you this. How hard are you trying to avoid doing any alterations to your bus? Depending on local laws and regulations you might be able to drill holes through the rear crossmember for your radiator pipes / hoses. Where I am which is unbelievably strict, I can but may have to weld on a reinforcement plate. If you find it is legal and choose to do so at some point get yourself a good holesaw and arbor, and plenty of lube. Just the holesaw and arbor set me back about $50 but it was a worthwhile investment for a clean, round hole through thick-ish steel.

My radiator hoses still run under the rear beam anyway so not much is gained there.
Really if you are worried about both airflow and ground clearance one of the most passable configurations without carving the front up is a roo bar mounted rad. Preferably mounted behind the bar and shielded with some kind of grille. The trouble with that setup is air bleeding unless you get creative and do something like get a radiator with a rad cap hole and get a blanking cap for it, and remove to bleed. There is one other drawback to that setup unless you shield the vent flap you'll have a nice hot airflow into the cabin.
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Vehicle: 1975 Special order delivery walkthrough panel based pop-top camper (LCA / Sunliner). Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.

[Bajatacoma]

I remember seeing one conversion where the person had mounted the radiator on the front and had fabricated it to look like a spare tire. IIRC he built a hoop around it and put one of those chrome cover things on the outside while the front was made of black painted expanded metal. From a distance you really couldn't tell it wasn't a spare and up close it was a clean install. Just a thought...
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'78 Westy

Who is the happier man, he who has braved the storm of life and lived or he who has stayed securely on shore and merely existed?
Hunter S Thompson

[El_Güero]

my best friends bus has a similar conversion (1.8 jetta ) shown in the first picture with the expansion tank in the spare tire compartment, he bought the bus from someone who had boght it from a mechanic who did it, his experience so far sugest that the engine doesn´t overheat neither on highway or traffic driving, the only disturbing matter for some folks is the fact that he has a second set of air scoops rivetted right beneath the original ones, (both sides) that makes the radiator get sufficient air from outside so it can cool off, and the fan only comes in when the bus comes to a stop. Hes not to worried about looks and so far so good.
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"Sé que en algún lugar sus dedos pelean con un tornillo" (Remembering Carlos Amat)

"Si quiero estar encabronado
hazte a un lado...cabrón!"

[greenbus pilot]

[avocado_tom]

[avocado_tom]

[RatCamper]

I haven't measured but I've probably lost at least 4" with the belly mount, and where I need it most too, between the front and back wheels.

Sorry, I don't remember what year your bus is. Drilling the hole for the rad hose kind of bothered me but the fact that my rear crossmember is full of holes for things that it never had helped my decision.
Also dependent on year model, fitting a fan may be interesting. My conversion was pulled from an earlier 1600 bay. The only thing I haven't had to modify so far would probably be the moustache bar. One of the more infuriating differences I found was the routing for the various conduits underneath. Where an earlier bay could accommodate the radiator and thermo fans without issue, mine couldn't. I could only fit one thermo fan in there because of the steel tubes. This will be revisited shortly as I plan on doing one more radiator pull to finish the thermo fans. I have to drain the coolant to do a hose reroute anyway so I'll get it all at once.

I'm currently blocking off the frame rail to floor gap and the extra holes in the rear crossmember with pool noodles which jam fit quite well, and will be making a bridging plate to stop airflow between the back of the rad and the rear crossmember. I know I've said it before but the devil is in the detail. things look done until I give them a good think over. By now I have completely changed the entire conversion making the "complete" setup pointless.
One good thing I've noticed is I can use it as a tug of sorts for dragging things around in the yard, including a ~1150kg caravan, heavy trailer and even dragged a pallet with a motor on it and it barely ever even turned on the thermo fan. So that's still air + lugging + load + small fan.

Back over to your issue. It's very sad that you can't get it done in time. I get that. Said I'd have my bay back on the road for Valla something like 7 years running and failed But I think you'll have it all sorted by Christmas as long as you are methodical, and don't let it get to you.
Keep up the good work. You have made excellent progress so far.
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Vehicle: 1975 Special order delivery walkthrough panel based pop-top camper (LCA / Sunliner). Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.

[greenbus pilot]

Quote:OOC, how are you pulling hot air off the engine? Shouldn't the air be drawn in from the scoop area? Or is this if you mounted it where the rear engine hatch is?


The worst overheating was before I ducted around the radiator, and it was just mounted in the engine door opening, pulling out through the back with the fan. It ran pretty hot all the time. The fan ran constantly on the highway because the exhaust is directly in front of it. It simply boils the coolant after a few hours. Been there. Done that. Almost rented a tow truck to get home about 1000 miles away, so I cut a flap in the drivers side, where the marker light is. Running the heater all day I was able to just keep it from boiling. When I got home I designed ducting to shield the radiator from the engine heat and pull from that flap I cut and the vents above. This was better but not perfect. I went to the belly mount later; those Aussies have it figured out pretty well....!
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Sent from a white van down the street.

[RatCamper]

[avocado_tom]

There are more details here, but suffice to say I took my first extended run in my bus without any major overheating issues.

Here's my setup:
- stock radiator and fan in the engine compartment
- 96 plate mesa-cooler from thermostatically oil filter sandwich adaptor
- small Ford heater core inline with the heater coolant flow and mounted under the bus with a scoop*

What changed and is helping me:
- mesa cooler is new
- ambient temps are low (50-60 degF)
- sealed the area around the radiator so no air could bypass it

Other notes:
- not sure how often the fan is coming on yet
- H2O temps stayed at or below 180degF for majority of trip
- kept my foot out of it: cruised mostly at 55 to 57 mph
- don't think the Ford heater core gets much flow after the t-stat opens[/url]

[avocado_tom]

All,

I'm giving up on my 1.6 VW Turbo-Diesel conversion project.

Anyone need parts for converting an early bay (or any ACVW) to a water-cooled VW - diesel or otherwise?

I have lots, including an mustache bar engine mount that has been modified for the water cooled engine.

[skills@eurocarsplus]

wow, 6 years later and throwing in the towel? may I ask why?
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[avocado_tom]

[greenbus pilot]

[avocado_tom]

Thanks Greenbus Pilot! You too!