Small 575mm vs 675mm radiator in Golf 2

[shwah]

Just wondering if anyone has experience running the smaller radiator in an 8v Golf 2 ITB car.

I am running the big radiator now, and have zero water temperatur issues. Ran on a very hot (mid 90s, 100 heat index) July weekend at Blackhawk and saw consistent 190 water temps. Runing a normaly hot (high 80s) June weekend at Road America ran right at the t-stat temperature of 180 (since changed to 160).

The issue is that I am just not satisfied with the location that I have my oil cooler mounted. The hose routing is more convoluted than I prefer, the clear view of airflow is not what I prefer and it is sitting in front of the radiator which will impede flow through both units. I have been running very high oil temps due to a shipping error on the oil cooler parts when we put the motor in prior to RA, and we did not get everythig sorted out until after BHF. Oil temps were in the 280-300 range with no cooler, and I obviously cannot continue to race like this - Soooo.

My thought is, if the water side is in really good shape, maybe going to the smaller core will work. I will gain space to install the cooler beside the radiator, both getting clean flow, and with proper shrouding, should be able to assure even better flow over both cores.

Is this a bad idea in your collective opinions? Anyone else been down this road, and has the scars to keep me from making a mistake?

thanks in advance

[JamesB]

The smaller radiator might work. When I got my car the previous owner was running a small radiator and blew up 3 motors. I went to the larger one and installed a 23 row cooler in front of the fan section of the radiotor. I did remove the flaps from the rad shroud to allow more air volume through. In 90ish degree temps in the mid atlantic area I only see 215-230 oil temps, 190-205 water temps during the race. I dont get the annoying overheating issues that matt gets with his 16v if I am in a draft for too long either.

The real nice part I like about my setup is I can turn on the fan (I run an override switch.) during my cool down laps and it will bring the oil temp back down to 190 in no time. I dont plan to change a thing.

[shwah]

I forgot to note that I do not run a fan or shroud on the back side, to promote better flow through the radiator core.

I find the heater enough (just) when I need to cool in the paddock.

[Sandro]

I am also interested as I will be buying a radiator in the next week for my car.

I would think it should work. If your oil is at the near 300 range and your going to install an oil cooler, that will lower your oil temps and in theory should lower the water temp. Right?? So then if your water temps are going to be a little lower the smaller radiator should be able to maintain the same temps.

[shwah]

After giving it some thought, I think this is something I will try in October, when the risk of getting it wrong is lower. Until then I will mount the cooler in front of the big radiator.

[Sandro]

You could also try blocking off one side to replicate the size of the smaller radiator and see if their is any change.

[pfcs49]

I used the small radiator with the factory oil/water intercooler.
I moved the radiator fully to the right for weight distribution and saved several "nosey" pounds by not running an oil radiator.
Oil and water temps were always good and stable w/190*F themostat (hotter is better-believe it or not) .
phil

[shwah]

Thanks Phil. I will definitley try this later in the year. I will just be sure to have brackets and hoses for both setups on hand in case it doesn't work well.

On the water temp, I guess different engine builders have different ideas. Mine wants the water colder...

[msogren]

Hot but controlled cyl temps make more power . The cyl pressure is higher.
I use the big rad tho as I dont like to be close on cooling. It can ruin your weekend and engine. I also live in FL.
I also run the stock oil/water cooler, along with Mobil one or castrol Syntec. Syns dont care about oil temp. and the Vw , with the windage tray, keeps the oil under 300, I think. I disconected the oil temp gauge and hook it to the water temp sender, . Oil temp is a non issue with the syn oils, dont waste your time, money and add weight to the nose, along with the additional leak potential spots , IMHO
FWIW the Golf /w air rad, fits the A1 and cost less. Stu, (Imparts)in NY has a few for a good price.
MM

[shwah]

I'm not very worried about the oil handling the temps. It is the bearings and other parts that have me concerned.

I don't know I may go back to the water/oil cooler. Ran consistently 240 oil temps with that.

[T Broring]

We have run the shorter rad and oil cooler in the open space next to the rad on an A1 Scirocco. Zero problems with water or oil temp. The important thing is to start with a new radiator that has no buildup inside.