48 replies to this topic

[Mattias]

I would not recommend getting rid of your oil/water matrix. Simply add more cooling to the oil circuit, but don't take stuff away. That thing will help reduce your oil temps (admittedly at the expense of your water system). Having over hot oil is more dangerous than over hot water.

 

 

 

I will of course add a temp sensor and sufficient air cooling capability. Water oil-cooler is more of a standard car optimal solution, it acts both as an oil warmer and cooler. Another aspect  to think about is that if engine temp is lowered then so is the the oil temperature. What I need to get an understanding of is how many kW the oem oil cooler is dissipating  to figure out how big the air cooler need to be to do at least the same job.

[Captain Vimes]

The water-oil cooler is effective in pulling heat out of the oil. The issue is that the CC rad is blocking the main rad, so the water isn't cooling, which is allowing the oil temps to climb. Rather than adding an oil-air rad, isn't the simpler solution to improve the water cooling? With the extra pump already added it could cope with an additional rad without issue.

[Mattias]

The water-oil cooler is effective in pulling heat out of the oil. The issue is that the CC rad is blocking the main rad, so the water isn't cooling, which is allowing the oil temps to climb. Rather than adding an oil-air rad, isn't the simpler solution to improve the water cooling? With the extra pump already added it could cope with an additional rad without issue.

 

As said before it doesn't seem to help that much to add a second water radiator of a size that can fit in the car:

 

Instead of adding an oil cooler, have you thought about adding an extra water rad to help bring water temps down and in turn oil temp?

 

Yes, that is why I removed the hose from the heater and tested a few laps with the heater on fully. It did help a little but not enough to keep the temps steady during several hot laps in a row.

 

 

The water-oil cooler is effective in pulling heat out of the oil. Yes, and all that heat is released back in to the engine cooling.

 

The question here isn't what cooling medium is more effective but rather how big the air to oil cooler need to be to do the same job and more.

Adding an oil cooler is easy, it's just two hoses and a cooler and possibly a fan if needed.

[Captain Vimes]

I'm sure swapping to an air cooler will help (with sufficient air flow and rad size) if the installation is easier. As for the water rad, I'm not sure turning the heater on is a good test of what could be achieved with a decent size additional rad in the cooling system. Acidpopstar is seeing water temps of 91 on hot track days without a pre rad up front, which gives a good indication of the impact it has on the efficiency of the main rad. I assume you've seen the Hoffman's thread where they got inventive in adding extra cooling for oil and charge coolers? http://www.hofmanns....ropa-build-blog

[Bargi]

 

 

which pump did you go for? Guessing the EWP150?

  EWP80 so I have to keep the belt driven pump also. But I wouldn't trust the davis craig pumps enough to remove it.   I will probably change to a Volvo oem cooling pump from Pierburg in the future that flows 150L/min and is well tested for durability.  

  can you put up a link to the pump you would use  

  It has recently hit the market in our 4-cyl VEA petrol engines, I will check the part number tomorrow.

Any chance you found out what the pump was?

[siztenboots]

easier to deal with water at 1bar, than oil pressure for all the hoses and fittings. also if debris was to damage a rad , the loss of water for that circuit is less harm than oil leak.

[Mattias]

 

 

 

 

which pump did you go for? Guessing the EWP150?  

  EWP80 so I have to keep the belt driven pump also. But I wouldn't trust the davis craig pumps enough to remove it.   I will probably change to a Volvo oem cooling pump from Pierburg in the future that flows 150L/min and is well tested for durability.  

 

  can you put up a link to the pump you would use  

 

  It has recently hit the market in our 4-cyl VEA petrol engines, I will check the part number tomorrow.

 

Any chance you found out what the pump was?

 

 

Yes, a used pump with almost no mileage cost 200gbp here in Sweden: http://en.bildelsbas...v/OEM/31368715/

 

P/N: 31368715

[Mattias]

I'm sure swapping to an air cooler will help (with sufficient air flow and rad size) if the installation is easier. As for the water rad, I'm not sure turning the heater on is a good test of what could be achieved with a decent size additional rad in the cooling system. Acidpopstar is seeing water temps of 91 on hot track days without a pre rad up front, which gives a good indication of the impact it has on the efficiency of the main rad. I assume you've seen the Hoffman's thread where they got inventive in adding extra cooling for oil and charge coolers? http://www.hofmanns....ropa-build-blog

 

Haven't seen that thread, thanks for the link. Interesting build.

 

One solution I was thinking of before going for the pro alloy was to have one radiator in each ear for the CC, would have been interesting to see someone try that.

 

I had a talk with the cooling expert at work today to get some general info to continue my investigation. The oem oil cooler probably transfers about 20-25kW and the front radiator on a standard car about 80kW. In general cooling the oil does 1/3 of the engine cooling. I will get on with calculating how big an air cooler need to be to remove 25kW to get an idea of if I will remove the oem cooler or not. 

 

One suggestion was to start with adding the air-oil cooler in parallel to start with. Adding it in series as it's usually done creates a pressure drop that affects the oil flow.

 

One interesting solution for adding cooling surface for both cc and engine coolant would be to get hold of finned pipes and run them front to rear and possibly adding some air flow. But probably hard to find a suitable alu-extrusion. Would be a nice stelth mod tough

[Mattias]

http://www.visokaa.c...inned_tubes.asp