Here is what they did at the Volkwagen factory in 1980.
A bug with a half kombi engine, yes two cylinder and 950 cc.
It was a prototyp with 33 HP.

To get to work on the engine, the radiator was hinged.

Holy moley! Thats certainly a new thing for me. Never seen it like that before. Not bad hp from a 2 cyclinder engine. lol

How did u come across that mate?

wow!!

Why ??

Maybe rather then the radiator swinging out like that, it should go up with the deck lid. Just an idea I spose.

Be interesting to be the vw guy trying out all that stuff.

I wonder if the radiator cooled down much at the pose. Probably had a few vents somewhere to direct cool air onto it or something.

[Edited on 17/6/2005 by mynameischris88]

I'm with brad, why? :duh

Hehehe

I wanna see the engine lid close!

If it was a VW deveoplment thing then I guess it maybe a hint to what goes on with the air flow back there.

Thanks subaruboxer for those pictures!

I am planning something like this set-up for my Alfa Romeo conversion. The thought that Volkswagen also tried this gives me comfort! I want to put the radiator at a slight angle on top of the engine. And then put scoops under the car to pick up cool air, and the hot air has to escape through the air vents in the rear decklid and above the rear decklid.
At least...that's the plan...

dude, just put it at the front, it works much better there. Trust me, my rads at the back and if I did it again it would be up front. Much more simple.

33hp for a twin cylinder? Better off chucking in a Harley Davidson V twin 80hp motor.

I'm running a rear mount radiator from the subaru L series behind my Ea82 engine with twin thermos its fine, and the thermos don;t run all the time. I don't eun an deck lid but hte car it came out of did. I will try to post pics if i can find them on my computer.

BJ

For those that really want to run a rear radiator how about some alternative thinking?

The sakar mid engine race cars http://www.saker.co.nz/  run 2 radiators just behind those scoops on the side of the car. Addmitedly the scoops are huge but the engine is pretty big to, and I'm sure someone mentioned a couple of mini radiators!!!!

How about a couple of radiators fitted under the rear seat- with scoops directing air in from under the car? Lots to sort out obviously like shifting the battery, opening the floor pan and then enclosing the passenger compartment.

But it gets the wieght forward of the rear wheels, but less wieght (less coolant, pipes etc), and away from the heat of the engine. Air should be easy duct in and out.

Any other ideas?

The one above looks painful to work around and just like the sort of thing that was done when the tech's were given an impossible deadline and / or budget!

Cheers
Jeremy

[Edited on 20/6/2005 by Jeza]

There is a heap of hot air generated by the box and the motor...any air passing across them prior to entering a radiator would be warm to say the least. The bonus of the front set up means you can run alot smaller radiator than normal because of the distance the water travels and the larger volume because of it. My radiator is tiny...10inches high x 20 inches. It fits snugly in the wheel well and is lower than the top of the water bottle.

The fact that VW tried it and we never saw it, may also say something!

Nice find though boxer..how is your car??

Matt

The best rear mounted radiator I have seen was a (Dutch or Belgian I think) bug done up in orange Benneton colours with design 90s.
It was running a wasserboxer with the radiator on the firewall, it had Remmelle style side scoops in the rear quarters that went back to the radiator which was fully ducted. It was features in Volksworld a while back.
Rich

what the?

I'm guessing (based on the 1980 date) that this was an experiment in low fuel consumption and / or low emissions ? 33hp would be enough to make a beetle move, though not real quick, and a 950cc FI halfa - wasserboxer engine would drink too heavily either ?

I'm sure you could mount the radiator under the parcel tray (ie above the gearbox) with some serious thought. Although I cant see the point - Boof has some very valid points with regards radiator size and coolant volume witht he rad up front.

I think about airflow too much!!!!

Ducting air to the back from the front or near the torsion bars is a good idea, although with the turbo I have other needs for the cool air at the back. These are intercooler, ram pod air filter and turbo.

At present I have 4x100mm pipes ducting from under the back window to my intercooler which has 2x9inch thermos in a box, I then will be using ducting from one side to feed the filter box, and the other side ducting will be ducted onto the turbo for extra cooling and heat dispersion. If you didnt have a turbo then the placing it behind the back seat like my cooler would work, although if your going to chop stuff up then just put it at the front...I am also making some 996 turbo style side ducts which I will use for my intercooler as there is not much unassisted air flow under the back window. I will try and get one moulded this week(along with all the other silly things I do not have time for.

matt

The theory that boof2332 has used with water travelling from front to back is correct. I run a Indy Car Alloy Rad. at the front without using a thermo fan while Racing with a temperture running 65degress.The only time i use thermo is when at idle with no air circulating.(RACE CAR use only)........This theory can be adapted to road use as well. Boys any sort of rad. must be force fed with direct COLD AIR... and must not have heat from engines,turbos etc near them.To much heat running around,over and in of motor which causes.......fans ,alternators,internals are over working.This causes a loss of hp.Please keep Rads up front!!!!!!!!!JVLRacing:thumbnn[ Edited on 4/7/2005 by jvl054 ]

Hi

In 1988 when I first fitted the WBX in my bug with radiator at the front, I travelled up to Nambucca for the VW Spectacular, this was its 1st long trip and I watched the gauges like a hawk, what I found was that at sustained 100 - 120 kph speeds the water temp would actually drop making me pull over a few times to make sure that there were no leaks etc, my thinking was that coolant level had dropped and that there was nothing activate the sender.

In short front mount is best.

PS if you wanted to look at efficient 2 cylinders motors, a Harley motor is a pretty poor example.

Steve

hw bout porsche style vents just im front of the rear guards and have a box behind the rear seat with the radiator in it??/

Why are you all so opposed to a rear mounted radiator? Don't you see the advantages of one?

The main problem for doing a conversion for a lot of people is cutting up the nose of their beetle.
This plus the fact that a rear mounted one is almost invisible is a reason for me to give it a try.
And I could go back to aircooled without leaving too much of a trace of the watercooled "experiment".

I must add that I am not after the maximum horsepower. I just want a factory spec engine that will cruise at 120 km/h on the freeway without a problem and without the feeling I'm sitting in a jet-figther.
Plus I want to get along with stop an go traffic running around town (Yes, my current 50 hp 1600 beetle engine can do this too, but....it doesn't like it...).
I don't care that I will loose some hp because of the fans coming on a little more than normal. As long as the sound of them don't drive me crazy...it's OK with me.
The engine I've choosen is a 1.4 Alfa Romeo boxer engine with 90 (european) hp . Yes, a small engine by displacement, and I hope this will generate less heat.

Picture:

I am not against them, I just have no room at all for one!
With the Australian summer and the uncertainty of how well any custom set up will work, the idea of having it up front with extra water/coolant for a helping hand, and the gauranteed cool air .....its one less headache to worry about working properly.

No one I know had issues cutting the nose cone. Jak has his where the spare wheel sits in a super and it is hidden. You can see mine because I chose that look(no bumpers doesnt help) Steve's yellow bug was pretty much hidden.

If I did an oval I would run two small radiators behind each headlight with a little hidden scoop helping air up..like the 996 has.

Matt

Hi

When I sold my yellow bug I converted it back to air cooled, just needed to buy a new spare wheel well, if I had kept the old one that could have been welded back in. Another advantage of the front mounted cooler is that there is more weight in the front for better distribution.

Steve

Hillman Imps also ran a rear engined, water cooled motor, with a very small rad in the rear engine bay.but iam pretty sure it has ducting, will go and have a look tonite.

Yep! Found a picture:


[img]http://www.theimpclub.co.uk/modules/mx_smartor/album.php?smartor_mode=album_pic&pic_id=175[/img]

well I guess someone who has tried it should chime in.

I run a rear, or should that be mid, radiator. It is above the gearbox. The main reason was because I could, I had to cut the firewall for the air intake anyway so what's a bit more metal.

The second reason is I thought that would be the safest location for it while offroading.





I made a removeable aluminium panel to cover everything and seal the interior. The back seat and my subwoofer / speakers all still fit (see pic below).

So far I have found that it works fine within reason. On the hottest february day on record when the temperature was 42 degrees and I was driving up a mountain range with a car full of camping gear, it got hot. I pulled over for 3mins with it idling and it cooled back down so I continued.

Around town there is no problems.

On the highway it's fine up to 100kph, but 110 and over it starts getting hot. This is because I am getting the air from underneath. At slower speeds the air turns and goes up to the radiator just fine. At higher speeds the air is going so fast it doesn't turn. It seperates at the torsion bars and creates a low pressure air pocket at the gearbox, just below the radiator. This causing the problem.

The solution is to simply add a couple of small air deflectors under my torsion housing or trailing arms to deflect a little air up towards the radiator at high speeds. Because it's ok at legal speeds I haven't bothered with the deflectors just yet.

The other problem I had was the shear heat off the radiator was cooking the interior of the car and making sitting on the back seat unbearable. I have since fixed that problem by lining the radiator side of the aluminium with that aluminium foil / sound deadening material thermal insulation sheeting. It works fantastically well and really keeps the heat out.

If I didn't have the offroader and wasn't worried about a front radiator hitting the ground, then I would go with a front radiator.