Dr.Jeff
True Classic
Lately I've been working on the nose area of my current X project, including the cooling system components that are located there. In two other threads [links below] I discussed the shape of the "box" area surrounding the radiator and electric fans. So in this thread I will give a description of the radiator I am using for this build. Let's be clear up front: I am not saying the X needs a different radiator, I am not saying one radiator is better than another, I am not suggesting there are inherent flaws in the X's stock original cooling system (although I believe there is), and the opinions stated in this post are just that...my opinions and no implication of fact.
My two other related threads:
Also see the cooling system thread by @Jonohhh:
I have a good condition stock radiator, but it really should be rodded out to be reliable. And for this build I'd like one with a bit more cooling capacity than the stock unit (mostly a function of the climate I'm currently living in). I also have one of the aftermarket "fabricated" aluminum radiators sold by a popular Fiat specialist vendor, but it is being used on another X. And frankly I'm not too impressed with it. So I opted to use a VW radiator, as has been discussed on Xweb before, mostly because I already had it (I also build VWs).
The concept of using a VW radiator in the X is certainly not new. This report dates back to 2008:
www.tapatalk.com
This was in 2009 (pic links are dead):
Pete did this nice installation in 2010:
And another one from the same year:
Plus other discussions about it in several threads. Therefore I am not reporting something new or novel. But I would like to add some info that was either missing, incorrect, or outdated in the references I found.
First, what is a VW radiator? In general it has a similar shape to the X rad; long (width) and short (height), with a tank on each end. The VW rad has a aluminum core and plastic tanks. One tank has a temp sensor hole that is the same size and thread as the X's, so you can use the stock temp switch. The other tank has both coolant hose connections (this is different to the X with one hose on each tank). The VW rad uses the same size hoses as the X, but with both being on one side you will have to reroute one hose (more on that later). At the top there is a small hose barb.... on a VW it connects to the overflow bottle but I used it as the air bleed (also more later). There are mounting bungs on both sides (front and back) of both tanks to install electric fans and a AC condenser (which I also have). The VW rad is significantly lighter than the X's, it is more efficient, and it is readily available and extremely affordable (especially compared to the X's).
Second, I'd like to clear up a common misconception. The VW radiator that is often used on the X is not a "Scirocco" radiator per se. Although some Sciroccos used it, there were many other models of VW that utilized the same unit. And in fact there is a different rad that is unique to some years of Scirocco which cannot be used here; it has a built in overflow tank with the fill cap as part of the rad. Additionally if you search for a "Scirocco" radiator you are severely limiting your options, as it was one of the lesser applications to use these units. For that reason it is also likely to be priced much higher despite being the same unit as one of the less costly listings.
The more common models of VWs to use these radiators were Mk1 and Mk2 Jetta, Golf, Rabbit, Caddy, Cabriolet, some Passats, a Vanagon, and others. Additionally there were several different sizes of rads used on those same VW models. Some were designated for AC cars, or for use in "tropical climates", or with diesel engines, or for various displacements of gas engines. And if that wasn't confusing enough, the VW part number system can be a bit tricky. Not to mention the aftermarket part suppliers often misuse the part numbers, giving incorrect numbers for some parts.
In order to sort all of this out it is best to NOT use a "year/make/model" approach. That will inevitably lead you in the wrong direction. To begin a search, start with a part number for one such application...keeping in mind there will be lots of variability. The VW part number system is grouped into three sections, each a three digit number; the first defines the model of car, the second the subsystem on the car, and the third the part within that subsystem. That is often followed by one or more letters; they designate differences that exist in the part, such as with updated designs, or in this case the size of the radiator.
Now let's talk about the size options for VW rads within this range. This pertains to the core dimensions only, not the overall size complete with tanks, etc, because that is how VW refers to them. The length (width) can be 480, 525, 570, or 675 mm. The height can be 300, 310, or 322 mm. And the thickness can be 30, 32, or 34 mm for two-row units. There is a three-row option for some but the ones we are most likely to use are commonly two-row. Also there are other lengths, heights, and thicknesses beyond these but let's keep it to ones we might consider most.
The core length primarily determines the unit's capacity. The 480mm unit is about the same capacity as the stock X rad. 525mm is a little larger capacity than the stock rad, and the longer ones more so. However ALL of them are much more efficient than the stock X rad. For one the core is aluminum, and second they are a "high efficiency" core design (which the original X rad was not). To put things in further perspective, I estimate the 525mm unit is approaching the performance of the custom aftermarket "fabricated" units made for the X, and the 570mm should out perform them. You can also get aftermarket "fabricated" aluminum units for VWs (similar to the ones offered for the X, but larger) with even greater performance.
As far as heights go, the shorter the better. All of the VW units are taller than the stock X rad. I used one with a 320mm height and overall it is about 30mm (roughly 1") taller than the stock rad. However that does not necessarily mean it will sit that much lower on the bottom; the method of installation will determine where the bottom is. First, the position of the top of the VW rad (fore and aft on the car) will affect the bottom height. That's because of two factors. One, the "box" area where the rad mounts has a bit of a peaked roof. By placing the top of the rad at the highest point of that peak you keep it as far up as possible. This means the top mounts will be located just behind (rearward) of the stock X top mount. And two, the angle of the rad changes, allowing more working room (it also makes the unit more vertical and perpendicular to the oncoming airflow from the front of the car). Doing that placed the bottom of my VW rad about 20mm lower than the stock unit. Additionally, if you use a modified stock X lower rad mount then you lose another 10 or so mm due to its stamped design. I fabricated a new lower mount and did not lose any additional clearance.
Here's the style of mounts used on VW radiators:
The bottom mounts came in two styles; earlier models had a flat pad that bolts-down, later ones have pins that drop into matching holes:
Early bolt-down (prone to breaking, not recommended)....
Later pin style (most commonly found today)....
The bottom pin mounts are easy to adapt. Just drill a pair of holes in whatever lower mount you use and place the VW rubber washers in between the rad and the mount...
The upper mounts consist of a slot in the top of each end tank. That's where "tabs" bolt onto the VW's rad support to hold the rad:
Upper mounting tabs...
To install it in the X the upper mounts will require the addition of a pair of tabs, similar to those shown in the above pic. You can bolt them in from above (through the frunk) by adding slots for them to pass through. Or, since the lower mount can be lifted up into position, the upper mounts can be 'fixed' by welding them onto the roof of the box from underneath (that's what I did). This way the rad is installed in a similar way as the stock X rad. Since the top is placed just behind the X's stock top mount (on the body) there is no need to remove or modify it.
As mentioned earlier I utilized the small overflow hose barb as a air bleed port. It is located at the top of the radiator, on one of the end tanks. I attached a hose to it, routed downward to the bottom, then mounted a small radiator "drain valve" on the other end. To bleed out any air simply crack open the valve. With it being at the bottom you will not get coolant leaking over the front like with the stock rad.
Getting back to what I said earlier about the coolant hose attachments. As mentioned the VW rad has both hose connections on the right tank. Prior threads have described approaches to attach the X's metal coolant pipes (under the car) to the VW unit (search for those threads). One of the hoses is easy, it is about the same as the stock X connection. The other side must cross over to the right side, typically accomplished by using a longer "S" shape hose. In my case I needed to replace the metal cooling pipes anyway, so I made them to fit the location of the VW connections.
Also some have said the X's hoses felt loose when connecting them to the VW rad. Mine did not. But I've found there are variances in X hose diameters depending who makes it. Regardless, a good hose clamp will make them secure.
Perhaps one of the greatest benefits to using a VW radiator is their wide availability and low cost. They start (delivered) as low as $40 USD, but decent ones run closer to $60. Some units are higher; for example the Passat application (675mm) is around $100. You can get the aftermarket "fabricated" aluminum units for VWs for less than one-third the price of those for the X.
So which VW radiator is the better choice? The longest one (675mm) is almost too long. Physically it will fit but the mounting locations are further apart (due to the tanks being further out), making it much more difficult to fab new mounts for it. And it is the most expensive; for just a little more you can buy one of the custom fabricated aluminum units - offering maximal performance. On the other end of the spectrum, the shortest one (480mm) also isn't the best choice. The capacity is only about the same as a stock rad, and it sells for the same price as larger VW ones. Although the one that is most commonly used in VWs is the 525mm, I feel the better choice for the X is the 570mm unit. Greater capacity for the same price as the 525mm and readily available. A typical VW part number for it is 171.121.253.CL (Nissens 65264). However you will also find it with several other model designations (the first three digits). But pay attention to the "CL" portion at the end. That should specify the length. Although as I said earlier, many vendors list them incorrectly. To be sure you are getting what you want look for a listing that gives the actual core dimensions. It is offered on eBay, Amazon, and from many VW suppliers for $60 USD delivered.
This X will not be on the road for quite some time as it continues with plenty of customization and modifications. So I cannot offer any actual measurements or hard data regarding the VW rad's performance. As I clearly stated in the beginning, this is merely my opinion and no statement of fact. For me it was a matter of preference, but I also regard it as a upgrade; MUCH lighter, more efficient, and extremely affordable.
[I'll try to get some pics to add later]
My two other related threads:
Observation for radiator airflow
I know the X's radiator has received a lot of discussion on Xweb, including the flow of air across it. However I don't recall mention of this particular facet that I've been observing as I make some modifications to the nose of my current build. You will recall talk about how the air hits a...
xwebforums.com
Radiator Electric Cooling Fans
In another (related) thread we've been talking about radiators. It reminded me of a great family company in SoCal (Mattson Custom Radiator in the City of Stanton) that has been building custom radiators, as well as all related aspects, for decades. It was started by the grandfather (Jack...
xwebforums.com
Cooling System Build Thread
Hi all. So, despite the list of things to do to my X1/9 being quite long, one has taken precedence over the last couple of months. I must admit, most of my motivation comes from not wanting to do a head gasket replacement due to an overheat. My old and Italian cooling system is barely holding...
xwebforums.com
I have a good condition stock radiator, but it really should be rodded out to be reliable. And for this build I'd like one with a bit more cooling capacity than the stock unit (mostly a function of the climate I'm currently living in). I also have one of the aftermarket "fabricated" aluminum radiators sold by a popular Fiat specialist vendor, but it is being used on another X. And frankly I'm not too impressed with it. So I opted to use a VW radiator, as has been discussed on Xweb before, mostly because I already had it (I also build VWs).
The concept of using a VW radiator in the X is certainly not new. This report dates back to 2008:
Xweb-Radiator...VW Scirocco install (dial up warning!!!)
I finished my own VW Scirocco radiator install today!!!! It took me a few weeks, mostly due to not having the right tools on hand and a few odd parts
www.tapatalk.com
Scirocco radiator and fan pics
Here's a few shots of my Schirocco conversion. It was more of a pain than I thought it would be, especially the air purge hose. It's pretty nice tough, keeps things cool. Fans are A LOT quieter than the stock ones. It doesn't really stick below the spoiler, except for the two plastic nubs that...
xwebforums.com
Yet another VW Scirocco radiator story
Hey all, Last weekend I completed my Scirocco radiator conversion on my 87 X. I wanted to drive it a bit before posting about it, so I could detail not only the install, but also the effects, positive or negative. I'll save you the wait and tell you now that I am greatly pleased. I sourced...
xwebforums.com
My Vdub radiator install
Hi everybody this is my version on the Volkswagen Scirocco Radiator replacement for the factory Fiat unit .When I first saw the discussion thread on it I thought wow that is so cool but when I noticed that it hung 2 inches lower than the factory radiator Oh that’s no good no disrespect to anyone...
xwebforums.com
First, what is a VW radiator? In general it has a similar shape to the X rad; long (width) and short (height), with a tank on each end. The VW rad has a aluminum core and plastic tanks. One tank has a temp sensor hole that is the same size and thread as the X's, so you can use the stock temp switch. The other tank has both coolant hose connections (this is different to the X with one hose on each tank). The VW rad uses the same size hoses as the X, but with both being on one side you will have to reroute one hose (more on that later). At the top there is a small hose barb.... on a VW it connects to the overflow bottle but I used it as the air bleed (also more later). There are mounting bungs on both sides (front and back) of both tanks to install electric fans and a AC condenser (which I also have). The VW rad is significantly lighter than the X's, it is more efficient, and it is readily available and extremely affordable (especially compared to the X's).
Second, I'd like to clear up a common misconception. The VW radiator that is often used on the X is not a "Scirocco" radiator per se. Although some Sciroccos used it, there were many other models of VW that utilized the same unit. And in fact there is a different rad that is unique to some years of Scirocco which cannot be used here; it has a built in overflow tank with the fill cap as part of the rad. Additionally if you search for a "Scirocco" radiator you are severely limiting your options, as it was one of the lesser applications to use these units. For that reason it is also likely to be priced much higher despite being the same unit as one of the less costly listings.
The more common models of VWs to use these radiators were Mk1 and Mk2 Jetta, Golf, Rabbit, Caddy, Cabriolet, some Passats, a Vanagon, and others. Additionally there were several different sizes of rads used on those same VW models. Some were designated for AC cars, or for use in "tropical climates", or with diesel engines, or for various displacements of gas engines. And if that wasn't confusing enough, the VW part number system can be a bit tricky. Not to mention the aftermarket part suppliers often misuse the part numbers, giving incorrect numbers for some parts.
In order to sort all of this out it is best to NOT use a "year/make/model" approach. That will inevitably lead you in the wrong direction. To begin a search, start with a part number for one such application...keeping in mind there will be lots of variability. The VW part number system is grouped into three sections, each a three digit number; the first defines the model of car, the second the subsystem on the car, and the third the part within that subsystem. That is often followed by one or more letters; they designate differences that exist in the part, such as with updated designs, or in this case the size of the radiator.
Now let's talk about the size options for VW rads within this range. This pertains to the core dimensions only, not the overall size complete with tanks, etc, because that is how VW refers to them. The length (width) can be 480, 525, 570, or 675 mm. The height can be 300, 310, or 322 mm. And the thickness can be 30, 32, or 34 mm for two-row units. There is a three-row option for some but the ones we are most likely to use are commonly two-row. Also there are other lengths, heights, and thicknesses beyond these but let's keep it to ones we might consider most.
The core length primarily determines the unit's capacity. The 480mm unit is about the same capacity as the stock X rad. 525mm is a little larger capacity than the stock rad, and the longer ones more so. However ALL of them are much more efficient than the stock X rad. For one the core is aluminum, and second they are a "high efficiency" core design (which the original X rad was not). To put things in further perspective, I estimate the 525mm unit is approaching the performance of the custom aftermarket "fabricated" units made for the X, and the 570mm should out perform them. You can also get aftermarket "fabricated" aluminum units for VWs (similar to the ones offered for the X, but larger) with even greater performance.
As far as heights go, the shorter the better. All of the VW units are taller than the stock X rad. I used one with a 320mm height and overall it is about 30mm (roughly 1") taller than the stock rad. However that does not necessarily mean it will sit that much lower on the bottom; the method of installation will determine where the bottom is. First, the position of the top of the VW rad (fore and aft on the car) will affect the bottom height. That's because of two factors. One, the "box" area where the rad mounts has a bit of a peaked roof. By placing the top of the rad at the highest point of that peak you keep it as far up as possible. This means the top mounts will be located just behind (rearward) of the stock X top mount. And two, the angle of the rad changes, allowing more working room (it also makes the unit more vertical and perpendicular to the oncoming airflow from the front of the car). Doing that placed the bottom of my VW rad about 20mm lower than the stock unit. Additionally, if you use a modified stock X lower rad mount then you lose another 10 or so mm due to its stamped design. I fabricated a new lower mount and did not lose any additional clearance.
Here's the style of mounts used on VW radiators:
The bottom mounts came in two styles; earlier models had a flat pad that bolts-down, later ones have pins that drop into matching holes:
Early bolt-down (prone to breaking, not recommended)....
Later pin style (most commonly found today)....
The bottom pin mounts are easy to adapt. Just drill a pair of holes in whatever lower mount you use and place the VW rubber washers in between the rad and the mount...
The upper mounts consist of a slot in the top of each end tank. That's where "tabs" bolt onto the VW's rad support to hold the rad:
Upper mounting tabs...
To install it in the X the upper mounts will require the addition of a pair of tabs, similar to those shown in the above pic. You can bolt them in from above (through the frunk) by adding slots for them to pass through. Or, since the lower mount can be lifted up into position, the upper mounts can be 'fixed' by welding them onto the roof of the box from underneath (that's what I did). This way the rad is installed in a similar way as the stock X rad. Since the top is placed just behind the X's stock top mount (on the body) there is no need to remove or modify it.
As mentioned earlier I utilized the small overflow hose barb as a air bleed port. It is located at the top of the radiator, on one of the end tanks. I attached a hose to it, routed downward to the bottom, then mounted a small radiator "drain valve" on the other end. To bleed out any air simply crack open the valve. With it being at the bottom you will not get coolant leaking over the front like with the stock rad.
Getting back to what I said earlier about the coolant hose attachments. As mentioned the VW rad has both hose connections on the right tank. Prior threads have described approaches to attach the X's metal coolant pipes (under the car) to the VW unit (search for those threads). One of the hoses is easy, it is about the same as the stock X connection. The other side must cross over to the right side, typically accomplished by using a longer "S" shape hose. In my case I needed to replace the metal cooling pipes anyway, so I made them to fit the location of the VW connections.
Also some have said the X's hoses felt loose when connecting them to the VW rad. Mine did not. But I've found there are variances in X hose diameters depending who makes it. Regardless, a good hose clamp will make them secure.
Perhaps one of the greatest benefits to using a VW radiator is their wide availability and low cost. They start (delivered) as low as $40 USD, but decent ones run closer to $60. Some units are higher; for example the Passat application (675mm) is around $100. You can get the aftermarket "fabricated" aluminum units for VWs for less than one-third the price of those for the X.
So which VW radiator is the better choice? The longest one (675mm) is almost too long. Physically it will fit but the mounting locations are further apart (due to the tanks being further out), making it much more difficult to fab new mounts for it. And it is the most expensive; for just a little more you can buy one of the custom fabricated aluminum units - offering maximal performance. On the other end of the spectrum, the shortest one (480mm) also isn't the best choice. The capacity is only about the same as a stock rad, and it sells for the same price as larger VW ones. Although the one that is most commonly used in VWs is the 525mm, I feel the better choice for the X is the 570mm unit. Greater capacity for the same price as the 525mm and readily available. A typical VW part number for it is 171.121.253.CL (Nissens 65264). However you will also find it with several other model designations (the first three digits). But pay attention to the "CL" portion at the end. That should specify the length. Although as I said earlier, many vendors list them incorrectly. To be sure you are getting what you want look for a listing that gives the actual core dimensions. It is offered on eBay, Amazon, and from many VW suppliers for $60 USD delivered.
This X will not be on the road for quite some time as it continues with plenty of customization and modifications. So I cannot offer any actual measurements or hard data regarding the VW rad's performance. As I clearly stated in the beginning, this is merely my opinion and no statement of fact. For me it was a matter of preference, but I also regard it as a upgrade; MUCH lighter, more efficient, and extremely affordable.
[I'll try to get some pics to add later]
Last edited:
