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radiator in the back idea

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1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 ·

#679182
gerrelt wrote: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.
Hi

Jak Rizzo is running his radiator at pretty steep angle, the angle does aid with cooling as it forces the incoming air around a corner which wipes of more heat, you must have it all boxed in to make the air get forced through and do its work.

Steve

Jaks radiator

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#679295
This is an old thread! Good to hear about your discovery Wes. Have fun at the beach!

I just realised I never updated this thread anymore.

I didn't do the dual rad setup because I couldn't find a suitable small rad for the front, and all the bends and connections would be too complex.

So, I just cut a bigger hole in the front, and placed the original radiator there:



With rad and fans installed:


With the cover on it:

As you can see, I now put my spacesaver spare wheel upright. I only loose a little luggage space this way.

Put some holes in the front:

I am quite sattisfied with the looks:


Made some coolant pipes out of exhaust pipe, used a bender, but welded the tight bends:


Painted and installed:

In engine room:


After a leak I replace a piece of it with flexible hose to make room for engine movement:

This solved a "hose walking off" problem in the right rear.

Some diagrams illustrating bleed points and reservoir position:



The hole system now takes more then 10 litres of coolant... 🤪
A long piece of small diameter coolant line is used to bleed the air out of the radiator. I hang it high, taped to the front decklid, so it will be higher than the fill reservoir. Then I start filling the system through the reservoir. When it's totally full I plug the before mentioned small diamter coolant line and hide it rolled up somewhere near the radiator. This works very good and simple.

It cools great now! The (dual) fans only came on briefly when standing still for a long time on a hot summer day. That happened two times during the summer season. They haven't been on since!
The temps stay on 90 degrees.
I've done some long trips now, on which I drive at 130 km/h for longer periods of time (1 hour or longer) and the water temp then sometimes rises over 100 degrees. But, I don't trust the sender, because the oil temp stays at 90 degrees. And (with the rear radiator setup) the fan sometimes switched off while the water temp gauge read 110 degrees. The temp switches of at 92 degrees... I think the sender is influenced by external heat sources.

It sure is fun passing all those modern cars (and some beetles) at 130 km/h in the left lane! Most people don't believe it.. 😏

All I want to do now is replace the distribution belts and tensioners and place the airfilter in a different spot or shield it from hot air.
Here in the Netherlands it is getting colder (fall) and I noticed the engine is starting to run better. I think it picks up hot air from the engine.

I surely enjoy the proper heater now. 😵‍💫

Future plans:
- rear disc brakes (no more adjusting drum brakes)
- LED daylight running lights (hidden in fog-lights)
- create some rain gutter fillers to reduce windnoise at higher speeds (see: www.vwkd.co.uk topic)

See my page for more detailed stories and pictures of the conversion.

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#679330
I can't even remember why I didn't realise only 1 fan was working when I first did my conversion, but I think I thought it just wasn't coming on because I hadn't hooked up the air con yet (I figured it was the condensor fan at low speed, and then a cooling fan at high speed).

I've never known what temperature it runs at, because I just use the factor Mazda gauges with the C to H gauge. It normally ran around the middle mark, which is where the thermo turned on and off of it's low speed setting.

The Davies Craig water pump controller essential shows 95 via the LEDs.


So for the last month or so it had been going all the way up to >95oC on the controller. The Mazda temp gauge was still roughly in the middle, and the thermo was coming on and off. I think now that it was the high speed circuit of the fan turning on and off, and that the low speed circuit had the dodgy connector and wasn't working too often.

Since fixing the dodgy connection and connecting the earth to the second fan, I have found both fans turn on low speed whenever the air con compressor is engaged. So they are both condensor fans as well as cooling fans. The only problem is that I put the condensor at the front, and it has it's on fan.

So on Saturday I drove to the buggyfest. My air temperature guage said it was 31-33oC most of the drive. Naturally I had the climate control set to a lovely 22oC so the air con compressor was engaging frequently. This mean the radiator thermo's were turning on and off of low speed frequently. I found that in this condition the Davies Craig controller was reading 75oC (I had it set to aim for 85oC). So basically it was over cooling. The Davies Craig controller is supposed to slow the pump in order to reach the correct operating temperature, but with both radiator fans switching on and off of low speed it wasn't able to do so. I have the controllers temperature sensor in the cold side of the radiator.

So I figured I was going to have to turn the air con off and see if it warms up (I didn't want to, it was hot outside). Once it was off the water temp came up to the 85oC, occasionally up to 90 and back to 85. Then I switched the air con back on and it went to 75 again.

I think this is ok. It would be nice if it got a little warmer. My thermostat used to be in the cold side and it was supposed to be 82oC, so it's obviously only a little colder than what the factor wanted. The Mazda temperature guage is still reading basically in the middle, but just a little to the left (the cold end).

This weekend will be interesting. First there will be a highway drive section, this is where it used to get a little warm. Then in the soft sand it will get a good test. Full throttle in third gear through the soft back part of the beach would see the temp guage climb. I guess trying to cool 200HP (well less at those revs I guess) continuously does that.

Gerralt, I know what you mean about wind noise being the next problem. The beetle has a few issues. Yes there are the rain gutters, but the recessed windows are also quite a problem. Modern cars have the glass almost flush with the steel body. On the beetle you get little eddies in front of the rain gutters, behind them, behind the steel door frame where the glass starts, and in front of the steel door frame where the glass finishes. I used some stick on foam strips to try to make my quarter windows seal better to reduce the noise a little (foam strips made to seal house door frames).
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 ·

#679344
Hi gerrelt

That is a very neat set-up, I really like the way you have been able to keep some usable boot space.

On my WBX powered 1302 I could fill the coolant from a dry fill at the header tank in the back and then overfill the overflow tank and after a few warm up and cool down cycles any air would be expelled from the header tank and be replaced by the extra coolant in the overflow tank.

Wes, I have one of those water EWP systems that I was going to fit it to my WBX, I will be interested to see how it goes long term on your car, and where you live and drive should give it a good test, I may fit it to my STI motor.

Steve

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 ·

#679442
@ Wes:

Be careful fella as a lot of modern factory fit gauges are "dead" between 70-100° apparently. This is so that the driver doesn't panic about fluctuations/overheating!

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#679447
Yeah, I think that's the case with mine. The EWP controller can go up and down a lot and the factory gauge doesn't move. The thermofan hi and low switching points should be pretty accurate and consistent though.
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.

ian.mezz I never said, I could write or spell

3,913 posts · joined Sep 2004 ·

#679602
just remember the old Leyland mini in the front on the side guard.

the old speed way cars 20 odd years ago i remember them being in the back of the car where the back seat use to be.

and this one.

😂🤪😂🤪😂
car forums. where a lot of peoples good intentions end up taking a good old car off the road forever never ever to see the road again. 🥲

pete wood 23 Windows of Awesome

6,828 posts · joined Jan 2004 ·

#679624
ElusiveStranger wrote:@ Wes:

Be careful fella as a lot of modern factory fit gauges are "dead" between 70-100° apparently. This is so that the driver doesn't panic about fluctuations/overheating!
mmm, that would explain why my parents subaru never moves from "normal" even on a hot day, while I watch my buggy's gauge go up and down according to the conditions. I guess it makes sense...also gives me a little more faith in my setup.

Gerrelt, I'm not surprised you went with that in the end (sorry if I sound like I'm gloating, I'm not). For a street car, the front makes the most sense. And congrats on your nice clean installation too. No one would be any the wiser until you carved them up. 😂

BTW, can't get over how much the alfa looks like a subaru..or the other way round maybe, but you see what I mean.
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/

gerrelt Slammed & Awesome Dubber

88 posts · joined May 2005 ·

#679726
Thanks guys, for the compliments! 🙂

Yeah, it looks a like a subaru engine, especially the intake manifold. But it has quite a few differences. The oil filter is in a totally different position, the sump is a lot shorter (no shortening needed), and the thermostat is on the hot side.
The waterpump inlet is a bit in a awkard position, though.

Those standard temp gauges can't be trusted. The temp gauge that belongs to the Alfa 33 my engine came from has 70 degrees in the middle, see:

When the car is at operating temperature, the needle is in the middle, so everybody thinks, that this engine runs really cool. Wrong... the thermostat is open at 89 degrees, the fans switch on at 92 degrees... So, like all other cars, the operating temperature is around 90 degrees.
Another example of original temp gauges that are made to give the driver a good feeling instead of telling the truth 😂...

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 ·

#679968


I made it back from the beach yesterday, but couldn't post on the forum as the electrons in my house were broken (due to the massive storm that hit us).

So I tried the following; up the highway with my little scoop on, up the beach with no scoop, back down the highway with no scoop. All of this was with the water pump controller set to aim for 85 degrees C.

Highway with Scoop
Temp: 30-31 deg C (87oF)
Air-con On - Cruising it sat around 80oC in either 100 or 110kph zones. Within 1km of exiting the highway it was back to reading 75oC.
Air con Off - I only did this for a short period in a 110 zone, and it went from the 80 to 90oC and stayed there. I figured that 90 deg C was when the radiator cooling fans must turn on to low speed.

Beach with NO Scoop
Temp: 30-31 deg C (87oF)
Air-con On - It normally hovered between 75 and 85oC. Depending on how fast I was going and whether I was driving on the soft or hard sand. Most of the beach is 50kph now, with only a small 80kph section.

Highway with NO Scoop
Temp: 33-34 deg C (93oF)
Air-con On - It normally ran around 90oC, but if I went over 110kph (particular overtaking on the very long hill sections) it would go above 95 deg C. Off the highway (60-70kph) it ran around 80oC, except for when I had to out accelerate a Supra from the lights before the form 1 lane section forced him to take his rightful place behind me, at which point it went to 85oC.

So the first two situations I was happy with. It was nice and stable, perhaps a little on the cold side at times, although the Mazda gauge always read a normal temperature in the center of it's travel. Even when it went over 95oC on the controller the Mazda gauge barely moved. I remove my scoop on the beach because all it does is scoop sand onto the radiator and engine, which isn't very good. I left the scoop off on the way home just to see how much of a difference it made. I was surprised how much hotter it was running, even when the air con fans were on. I think it has confirmed my thoughts that I get a dead pocket at high speeds, but also that I get a lot of recirculation within that dead pocket. Air must come out of the radiator and goes underneath, to recirculate. The scoop must probably push this recirculating air away more than anything else. It's kind of surprising because the scoop is so small and simple.





My radiator sits above the gearbox. I have it seal to the cover plate which is at the front/top of the radiator. I also have the sides sealed to the body. I just don't have anything going from the back/bottom of the radiator to the bottom of the car. Mainly because this would be difficult to do with all the other parts in the way (starter, exhaust, gearbox, fuel lines, engine cradle bracing, etc). The two thermo's are fully shrouded so there is no area of the radiator that is not under the suction of the fans.







If I get bored enough over xmas, then maybe I will try making some sort of panel that goes from the back/bottom of the radiator down to the bottom of the car, to stop recirculation.
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.