Any body ditch the OEM cooling system on the diesels???

[53 willys]

You are a smart dude, probably know this, and if your brother in law has a rad shop he will tell you as well. That Al cools better than copper. Even if it is the same size dimmentionally if one rad has more fins, cores, it will cool better if made from the same material to another in comparison. So a newer style jeep rad that is the same size as a factory VW from the late 80 or early 90s will probably cool better.
I also have found to run 50/50 instead of 60/40 on my antifreeze setup. Seems like the more water the cooler they run. Water wetter absolutely rules as well. Every vehicle I have added it to has at LEAST a 20 degree F temp drop on the gauge.

I know aluminum cools better...but a copper core that is 2 row or 2 pass would work waaaay better then this thin fined, 1 row OEM rad..
when I posted 60-40 I was meaning 60% water 40% coolant...water dissipates heat WAAAAY better then straight coolant..I would run an even thinner ratio if it was not so darn cold here in the winters...























I got all my parts and o-rings rounded up for the volvo oil cooler..I'm gonna install it tomarrow and the super cool Tstat and see what diffreance JUST those two make....if thats not enough I'm probaly gonna go shopping in my bother in laws radiator books..if I still can find some thing I like I will go with the $275 Griffin...

[arb]

oh I was thinking you got a VW specific rad....but that looks like a van rad right?? just slightly bigger/thicker??
my brother in law owns a radiator shop....I was thinking I may just go look through his  books and find one with the specs I need.
I was thinking about picking up a new Jeep Cherokee rad...they are short and long and would probably fit the vw front end well.?

Yes, its the stock Caravan rad.... I'd do to his shop and browse too. I would not have used the caravan rad if it was not soooo cheep. Volume does a lot for price.  You're right that double rows cool better than single, in my case, this thicker single pass (double row of tubes) does more than enough cooling. Pulling that camper last summer proved it.

[regcheeseman]

Always had the exact problem you mention with my install as well. In the UK climate too.

I was running in a mk1 caddy with the caddy diesel rad (the biggest of all UK mk1 spec rads - yes, bigger than GTI)

My gas temps were fairly conservative.

I also had a IC in front of the rad which robbed a lot of flow.

I removed the stat which  DID IMPROVE the coolant temps but it would still heat soak badly when thrashed for 5 mins or more.

I took the flaps off the fan cowling which improved things further

I bought an Nissens performance ally core GTI rad which offered 25% better cooling, it was better, but not a solution. Opening up more holes in the front panel or a twin fan setup would have been the next step had I not sold the truck.


I'm now building another mk1 using the caddy rad with a top fill end from a scirocco 1.5 rad, a remote expansion tank housed under the wing - I believe this will have no benefits over the original system apart from cosmetic ones.

The Honda VFR800 coolant tank.


I will site the intercooler better, cut both holes out of the front panel and probably convert to twin fans if need be.

I also will have a remote oil cooler instead of the original emulsifier unit.

[theman53]

http://www.summitracing.com/parts/RED-80204/



It works as claimed in everything I have ran it in.

[lord_verminaard]

runs at 205* and if I stay on it for a long climb I could probably over heat it...although I'm really to scared to test the theory....3/4 up on the gauge is too warm for my liking..

so you tell me what else can be done???


I know some engines run warmer with headers and maybe that's a possibility with this as well??

205* isn't running all that hot- My Scirocco would run at least 3/4 up the gauge, it would go a bit higher on the highway- according to the VDO gauge that was in there, it would run at about 100* C, which is 212 F.  VR6 engines will commonly hit 220 under normal driving, the 3rd fan stage doesn't come on until 230*    Does your coolant temp warning light ever come on?  If not, then it's not overheating.

I would imagine that if you railed it up a hill the temp would climb to a certain point and stop.  Are you sure that the system is "burped" completely?  You also mentioned the possibility of a blown head gasket, I'd get that checked out too.

Brendan

[macka]

205* isn't running all that hot- My Scirocco would run at least 3/4 up the gauge, it would go a bit higher on the highway- according to the VDO gauge that was in there, it would run at about 100* C, which is 212 F.  VR6 engines will commonly hit 220 under normal driving, the 3rd fan stage doesn't come on until 230*    Does your coolant temp warning light ever come on?  If not, then it's not overheating.

I would imagine that if you railed it up a hill the temp would climb to a certain point and stop.  Are you sure that the system is "burped" completely?  You also mentioned the possibility of a blown head gasket, I'd get that checked out too.

Brendan

   railing it up the hill under load may be a lot more then the cooling system can handle if it is substandard, damaged or clogged. The other little trick is using a ford taurus fan and a manual bypass, or a lower temp switch. If you can get the air moving sooner, you have a smaller chance of getting up in temp, as long as you have a good cooling system.

[arb]

205* isn't running all that hot- My Scirocco would run at least 3/4 up the gauge, it would go a bit higher on the highway- according to the VDO gauge that was in there, it would run at about 100* C, which is 212 F.  VR6 engines will commonly hit 220 under normal driving, the 3rd fan stage doesn't come on until 230*    Does your coolant temp warning light ever come on?  If not, then it's not overheating.

I would imagine that if you railed it up a hill the temp would climb to a certain point and stop.  Are you sure that the system is "burped" completely?  You also mentioned the possibility of a blown head gasket, I'd get that checked out too.

Brendan

   railing it up the hill under load may be a lot more then the cooling system can handle if it is substandard, damaged or clogged. The other little trick is using a ford taurus fan and a manual bypass, or a lower temp switch. If you can get the air moving sooner, you have a smaller chance of getting up in temp, as long as you have a good cooling system.

Fans are good, but I have yet to connect my fan to a functing switch. Even pulling the camper last summer at 70 mph with no fan running at all - I did not over heat. 210 was the highest I got and 200 being the norm. I did not calibrate my gauge - wish I had, but its got to be close.

[zukgod1]

Mark,
Where did you get your water pump?

I'm tellin ya man, a rad like mine will take care of ya..

[LeonardoL]

Well.. I really can't say I had a "stock" OEM cooling system, but in some sort a way I had problems with high temperature, and I am about to replace the radiator/fan/intercooler for new ones, very different from the point-of-view of a standard/OEM VW cooling system.

The vehicle is not a VW, but a CJ-5 (see my signature), powered by a supercharged VW 1.9D 1Y engine (N/A). The radiator has the same used in Fiat Palio/Siena 1.7D (560mm x 322mm x 45mm), made from aluminium with plastic corners - apart from that, the system was the stock VW, plus an oil/water heat exchanger on the top of the oil filter.

As the car weight is a bit higher that stock VW vehicles (between 300 to 500kg heavier), the frontal air resistence is very big, and the tires are *huge* compared to any original VW car, the engine suffers a bit of heating when high throttle is needed, even if is just for a little while.

To solve the current limitations, I am changing the radiator for one made using the original 6cc Willys CJ-5 dimensions (421mm x 420mm x 64mm) made from copper alloy.

The new radiator has 1768,2 square centimeters or frontal area, and the older has 1803 square centimeters. It is a little smaller, but it covers front in a much better way. And besides being thicker, it has a better heat exchange - copper has TWICE the heat transfer of aluminium.

I am also changing the intercooler for one that has 2.5x the area of the older one, thus reducing a lot the temperature from intake when using full boost.

Last, but not least, I will replace the fan for one that covers all the back of the new radiator - which, for being more square-shaped, allows using a bigger and more powerful fan (between 40 to 42cm radius).

The oil exchanger (from a VW Santana 2.0 Mi) will be kept, as it makes a big difference in hot climates - 30oC is a bit common here, in the summer.

I had not tested the new system - actually, no intercooler is currently installed due to other modifications in course - but it probably will say goodbye to overheating.

This solution might not fit exactly in a stock VW car, but I think some ideas can be used to improve the cooling system in overboosted or very demanded engines - so here it is!

Cheers,
Leonardo

[lord_verminaard]

Not to threadjack, but Leonardo, I'd love to see more pictures of your build.  Any chance you could start a separate thread with some pictures of your rig?  I had a newer Jeep TJ, but sold it quickly before it rusted away.    I'd love to have a diesel-powered CJ-5 someday.

Thanks!

Brendan

[LeonardoL]

Not to threadjack, but Leonardo, I'd love to see more pictures of your build.  Any chance you could start a separate thread with some pictures of your rig?

Brendan,

No problem! I created this thread:

http://www.vwdiesel.net/forum/index.php?topic=21978.0

There are other places with additional info:

http://leonardol.fotopic.net (all pictures I had taken about the process until now)
http://www.4x4brasil.com.br/forum/showthread.php?t=44947 (original thread for the Jeep)

However, everything is written in brazilian portuguese in these two.

Cheers,
Leonardo

[TurboJ]

Just to bring up a point that hasn't yet emerged;
quite often high coolant temps on a tuned TD are caused by less-than-optimal injection pump settings.
If there's just a little bit too much fuel throughout the rev range, your engine can easily get hot.
I've known many examples of cars that have had this problem, and finding the perfect pump setup
has helped.

[smutts]

quite often high coolant temps on a tuned TD are caused by less-than-optimal injection pump settings.

If you have an 11mm pump, that is going to be 49% more plunger area. That is going to need more torque on the "wobble ramps" to drive it. That torque buries itself in the advance versus internal pressure mechanism of the pump. So, my guess is that there might be an effect on the dynamic timing of the pump. Higher injection pressures, or larger plunger diameters would in theory retard the injection timing, needing more internal pump pressure. Or not . If the engine doesn't sound at all naily, and the EGT's seem high, some subtle adjustments of the pressure regulator with the precision tools required, Hammer and drift  , might be where it is at.
What sort of MPG's are you getting at the moment?