Skip to content
Aussieveedubbers

radiator in the back idea

0 likes
Share Share on Facebook Share on X Share on Reddit
Log in to reply

SHMO Casual Dubber

25 posts · joined Oct 2005 ·

#474594
Well,

I thought I would throw in a few pictures of my engine swap. I haven't done much to it in the last SEVERAL months, but I am back on board and hope to have it up and running in the near future. I'm crossing my fingers this rear radiator idea works out...haha

SHMO






gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#474838
Hey SHMO, that is looking very good! At first I thought that the ecotec engine would look too big in the back of a but, but it fits your bug excellent!

Did you drive it allready?
SHMO wrote:
Aren't you afraid of having a air-lock on that down left coolant hose? It has a high point in it which can't be bled. Would that cause a problem?
I'm asking this, because I got the same problem, I have to route my coolan hoses over the engine to the radiator. The coolant hoses will be a high point in the system (the reservoir will be higher though) from which air can't escape. So I'm thinking a bleeder valve must be fitted or a small tube from the high points to the reservoir.

boof2332 Custom Title Time!

1,210 posts · joined May 2004 ·

#474840
The thing that makes radiator setups work the best is the relationship between air pressure infront/behind the radiator. If set up correctly the air will be drawn through rather than actually pushed. My intercooler is in the back where it normally sits on a wrx. I scooped the air onto it through the rear gaurds....see pic. It works awesome, although similar to Jak, even with a tiny radiator, my temps hit 88 then the thermo fans come on. This only ever happens in traffic....usually 84-86.

http://www.thesamba.com/vw/forum/album_page.php?pic_id=249708

Matt

SHMO Casual Dubber

25 posts · joined Oct 2005 ·

#474963
gerrelt,
I am not too concerned with the lower rad hose. It doesn't make much of a dip, and I couldn't foresee it trapping much air, if any. But, only time will tell. I have not completed the Ecotec swap yet. There is still a long ways to go. It is just mocked up for the pics.

Boof,
are you running a subie motor in that car? Any pics showing where/how you mounted your radiator?

SHMO

SHMO Casual Dubber

25 posts · joined Oct 2005 ·

#479045
Here are a few udpate pics of my completed (well...almost completed) radiator setup. The back seat still fits in and covers up all of the ugly on the inside. I will insulate the parcel area really well in hopes of keeping the heat out of the interior of the car.










SHMO

SHMO Casual Dubber

25 posts · joined Oct 2005 ·

#479046
Here are a few pics of the (again...ALMOST completed 🤪) business end of the car. I'm getting close boys.










SHMO

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#479067
My radiator has a hose that dips in almost exactly the same shape and I don't have any air-lock problems.

You will definitely need to insulate that radiator cover as heat will just go straight through it. I used this stuff;
http://www.automotiveinteriors.com/HEAT_SHIELD.htm

I put it on the radiator side of the cover, so the shiny aluminium foil coating faces the radiator and reflects most of the heat. It made a HUGE difference.

I used the foil tape on the edges, it's great stuff. It sticks really well. It's been on for about a year now and hasn't peeled off or anything like that.
Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#479085
That's looking good SHMO.

I came up with a similar design:



I covered the outside with tarboard (stuff specially made for sheetmetal so it won't vibrate) and the inside with sound deadening stuff (the same stuff you can use under the engine lid of a car).



See some more pictures on:
http://home.tiscali.nl/~gmolhoek/alfa/radiator_box/index.htm

Owh, and I got an airscoop done, see this page:

http://home.tiscali.nl/~gmolhoek/alfa/air_scoops_channels/index.htm

Greetings,
Gerrelt.

[ Edited on 22/4/2006 by gerrelt ]

SHMO Casual Dubber

25 posts · joined Oct 2005 ·

#479361
Hey Gerrlet,

I was just looking on your website. (very cool by the way) When I really started looking at your rad mount, I wondered why you decided on a sealed airbox design? Was there a reason you didn't leave the face of the radiator open to natural airflow? Just curious on the theory there.

SHMO

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#479551
I wondered why you decided on a sealed airbox design? Was there a reason you didn't leave the face of the radiator open to natural airflow? Just curious on the theory there.
I did that because there will not be much natural airflow in that area with my bug. It's not a baja, so the rear is more closed.
That, plus, this way I am more certain that there will be airflow through the radiator. The air can't do anything else but go through the radiator.
And this way only fresh cool air is used to cool it. There is absolutely no way it can catch allready used warm air.

I think I got this idea from the aircooled-setup. In that setup only cool air can be sucked in by the fan, and all the airflow produced by the fan is used to cool the engine. The fresh "cold" air is strictly seperated from the used warm air (by the engine-seal). Only that setup is from top to bottem, and my setup is from bottom to top. Which, in a way, might be more logical because warm air wants to go up.

I hope it will all work out, the theory is nice but.......

SHMO Casual Dubber

25 posts · joined Oct 2005 ·

#520773
Well,

I have finally (for the most part) finished up my engine transplant and rear radiator. I thought I would put my two cents worth in regarding how it worked.

My setup consists of an aftermarket aluminum radiator and a single cooling fan, I think you aussies call them thermos. After completing my engine swap and dealing with some ECU issues, I have finally got a chance to do some actual drive time testing. At an idle my cooling fan will cycle about once every 10-minutes after the engine reaches its operating range. The fan actuates at 215 degrees (101 celcius) and pulls the temps down to 170 degrees (76.6 celcius) before shutting off. This is controlled through the engines ECU. Under a load during normal driving conditions the fan does cycle more often, but by no means does it continually run. I have taken the car up to roughly 100 mph (161 Kph, but in any measurement it's fast for an offroad car on the highway...hehe). I have also sustained speeds of well over 70 mph (113 kph) for extended periods of time. This was done with outside tempretures ranging bewteen 85-92 degrees (29-33 celcius). The engines temps have never climbed past that 215 (101 celcius) degree mark, and the coolant seems to drop almost immediately when the fan begins its cycle. All is good so far.

With that being said, I do have some future plans for the cooling system. I think I will install an additional low CFM fan actuated by a variable speed thermostat. I think this will help to maintain a more constant coolant temp.

Here are a few pics of my (semi) completed swap.

SHMO














1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 ·

#520790
Hi

That’s a nice setup. The temp drop your getting is huge and would most likely bring the temp below the thermostat opening temp. I had my temperature controlled by an aftermarket ECU and from memory had fans come on at 95 Celsius and cutout at 90 Celsius.

You might be better of with a non factory fan switch, Davies Craig make them, they are adjustable and only need to have a probe fitted into one of the hoses.

Steve

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#520837
sweet ride SHMO!

I agree, your thermo temp range seems really big.
Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

SHMO Casual Dubber

25 posts · joined Oct 2005 ·

#520858
Yep,

I totally agree that it ranges too much. That is the primary reason I am considering the second cooling fan.

SHMO

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#595240
I have my Alfa Romeo conversion running and I am driving it for about 2 months now (and enjoying it very much!!!!:bounce).



I do have cooling problems though. I am "debugging" it at the moment. I very soon discovered that the rear decklid wasn't venting enough and that the radiator fan couldn't suck in enough air through my air channels.
Once I fixed that, the car ran fine in city traffic, but now the challenge is to make it run cool on highway speeds. It still runs hot on higher speeds, probably because of not enough airflow to the radiator. Only the sides of the radiator get airflow. I am planning to create more air ducts.

Read my experiences on my page:
Link to my page, Gerrelt's Garage
Click on the picture, and then click on the link in the bottom of the screen named "Debugging the cooling system".

subaruboxer Officially Full-On Dubber

292 posts · joined Jan 2005 ·

#595973
Hello gerrelt,
nice to see that your beetle is on the road.
I think you have to get more air to the radiator and most important of all is to get the hot air out of the enginebay!
I would put it to a test with an open decklid, screw two little pieces of metall to the hinges at the top of the decklid. This will make a big difference, I am sure.
If you are satisfied with the open decklid, you could build something with a wiper motor to open it, if you don´t like it to be open all the time! But first you have to get more air the radiator. You need some serious shrouding!!

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#596636
Mine's been at the back for about 4 years now and is still ok...
Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#596667
ok, but can I ask you, if you were going to do the whole conversion again, from scratch, with everything you know, would you still put it in the back?
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#596845
pete wood wrote:[the ghost of ol'pete] "put the radiator up the fronnnnt..."

seriously.....
🙅 No, not yet. I only just began to fine tune it. And besides, putting it up front will bring up other problems. I will loose the place for the spare wheel, I'll have to find a place for the pipes, and, I don't think it will be good on the stock water pump, those long pipes. And bleeding the air out of the system will be more difficult.
The place where I put the radiator was space I wasn't using anyway.

But, if I really can't get it to work, It will go in the front, but I am a "little" hard headed....😁

I learned a lesson this weekend: don't use water pipes without an ridge to hold the hose in place:


I though I converted to a steam engine when that hose came off! 🙄

[ Edited on 13/6/2007 by gerrelt ]

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#597076
I'm pretty stubborn, so it'd probably go in the back again. 🙂

It has it's advantages. Safer from damage offroad, less water gives quicker heat up in winter (need that heater on a cold morning), mine doesn't need air bleeding at all (it does it itself after the initial fill), it doesn't heat up the fuel tank in summer.

Obviously from a cooling perspective the front is better, but the rear can be acceptable too.
Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 ·

#597090
Hi

I don't think that pumping the water to the front is an issue, the T3 Vanagon don't have anything special in the water pump area. The biggest problem that they have is bleeding, as their fill point is way below the top of the radiator. On my WBX bug I had no fill or bleed issues as the fill point was above the radiator top.

Steve

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#616969
OK, I've come to the conclusion that the rear mounted radiator doesn't completely work in a full body beetle. It works fine while driving around town and on country roads (80 km/h) with the assistant of fans, but at the highway it just doesn't work.
At 120 km/h for a long time the temperature rises over 100 degrees celsius.

But, it was worth a try.

Now, I am thinking about a "hybrid" setup: A small 40x40 cm radiator with fan in the back, and a longer but not higher one 60x20cm in the front connected in series.
The advantage of this setup is, I've allready got the room in the back for the small radiator plus fan, and the front radiator can (hopefully) be placed without cutting a lot in the nose. It will be place where normally the airconditioning condenser is in the american 1303 beetles.

I am thinking of the radiator from a Suzuki Alto in the back and the radiator of a Fiat cinqueciento in the front.

So, what do you guys think?

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#617033
IMHO, I think it's a bad compromise.
🙅
two identically placed rads, ala F1 car is ok, but 2 in odd places won't be nearly as efficient. It's like having a big radiator up front with 50% of it partially blocked. better to have big air intakes feeding 1 rear mount, or 1 front mounted altogether. Also, consider this. the more complex the pipe work, the harder it will be to bleed. all the extra pipework has to be routed and sealed as well.
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 ·

#617052
Hi

I didn't realize your car was a 1303. Maybe get a space saver spare and mount it on top of your fuel tank and then use the spare wheel area for your radiator.

Bugs@5speed do a low front mount profile radiator for 1302/1303s.

Also do a search on here for users called Jak Rizzo and 1303 and look how they did their front radiator set-up.

As for running hoses front to back, this what I did on my old 1302, the 1.5 inch stainless tubes followed the chassis bolts in the heater channel.

Steve



gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#617066
pete wood wrote:IMHO, I think it's a bad compromise.
🙅
two identically placed rads, ala F1 car is ok, but 2 in odd places won't be nearly as efficient.
It's like having a big radiator up front with 50% of it partially blocked. better to have big air
intakes feeding 1 rear mount, or 1 front mounted altogether.
Most cars on the road have the radiator covered by 50% or even more. If I look at my daily driver (2000 Peugeot 306 1.6 break), almost 75% of the radiator does not get airflow.
Wasn't there a rule mentioned somewhere that 30% of the radiator should get airflow?
pete wood wrote:Also, consider this. the more complex the pipe work, the harder it will be to bleed. all the extra pipework has to be routed and sealed as well.
Yeah, you are absolutely right. If I do this setup, I will have to strategically place some bleed-points.
That is the main problem with this setup, a lot of connections and bends.
1303Steve wrote:I didn't realize your car was a 1303. Maybe get a space saver spare and mount it on top of your fuel tank and then use the spare wheel area for your radiator.
Than I'd have to place the radiator at an steep angle. I am worried this will affect the effectiveness of the radiator. The airflow will come in at an angle too.
1303Steve wrote:Bugs@5speed do a low front mount profile radiator for 1302/1303s.
Yeah, I know, allthough it is probably rightfully priced, I can't spend that kind of cash on my beetle. I will have to do with some junk-yard radiators.
It is a nice multi core radiator, btw.
1303Steve wrote:Also do a search on here for users called Jak Rizzo and 1303 and look how they did their front radiator set-up.
I will!
1303Steve wrote:As for running hoses front to back, this what I did on my old 1302, the 1.5 inch stainless tubes followed the chassis bolts in the heater channel.
Thanks for posting your pictures.
I am thinking of running them under the tunnel. I allready have my fuel lines following the chassis bolts under the car. I guess that mounting hot coolant pipes directy next to the fuel lines is not a good idea?

Are there any thoughts on running flat square pipes? This might help in ground-clearance.

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#617076
gerrelt wrote:OK, I've come to the conclusion that the rear mounted radiator doesn't completely work in a full body beetle. It works fine while driving around town and on country roads (80 km/h) with the assistant of fans, but at the highway it just doesn't work.
At 120 km/h for a long time the temperature rises over 100 degrees celsius.
That's the problem mine had, it would get air up to about 100kph but around there and above the air wouldn't be able to turn up and pass through the radiator. The scoop on the trailing arm seems to have fixed my problem, but mine is a Baja so I get a lot of air flow under the car. I reckon some scoops through the side of the car in front of the rear fenders would help too. I just don't want to go cutting holes in my body.
Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#617182
Baja Wes wrote:I reckon some scoops through the side of the car in front of the rear fenders would help too. I just don't want to go cutting holes in my body.
Yeah, my thoughts exactly. Scoops in the side might work, a lot of sportcars use it also (the Ferrari Testarossa has big vents in the side to cool the radiators). But I don't like the way it looks AND I want to keep my rear seat.

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#679109
I have a bit of an interesting update to my rear radiator set-up. In the last year or so I noticed the temperature gauge start behaving a little odd. Ocassionally it would go up a bit higher than normal and then come back down. So I changed the thermostat first and it didn't fix it.

Then I thought maybe it was my waterpump, as far as I knew it was the original 1992 waterpump. So that convinced me to convert to a Davies Craig EWP (which also allowed me to remove a bunch of junk and unwanted belt off my engine).

After I install the Davies Craig it still had odd behaviour. Sometimes it would seem to cool too much, and other times it would say it was overheating (the Davies Craig water pump controller has a digital temperature readout in 5 degree C increments). Something was still odd.

So on the weekend I decided to have a good dig through my wiring harness. I checked all 6 relays for the 2 cooling fans (yes, 3 per fan). I found one of the relays had died. It had a water proof cover, but was sitting upside down, so it filled with water and corroded out. But even after replacing it I noticed that second fan still didn't come on at all. All the fuses were fine. So I decided to unplug both fans and test them. Well the working fans plug didn't want to come apart, and when it finally did one pin was really corroded. So I think that had been the recent problem. The corroded pin has been intermittently connecting, so sometimes it would work, sometimes it wouldn't.

But why didn't the other fan work. Well after more testing and chasing wires (I still don't have a wiring diagram) I found something. I found the earth wire for the second cooling fan, and I had never connected it to anything. So the whole time I have only ever had 1 of my 2 thermofans working 🙂 What an idiot...

So it cools a lot better now 🙂 I am going up the beach this weekend, so it will have a good test then.
Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#679122
thanx for filling us in on that mate. nice when people are honest about their mistakes. 👍

be interested to hear what your feedback from the weekend is.
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/