Keeping it Cooler
Oil Cooler Installation

By Adrian Teo, 08/05/2000

Heat Kills

Yes, heat kills. Oil is the lifeblood of your engine. Every moving part is protected from metal to metal contact  by a thin layer of oil no more than the thickness of a fingernail. As oil heats up, it becomes thinner (more so in mineral oils than in synthetic oils) and eventually the oil characteristics break down and you get metal to metal contact. Everything quickly grinds to a halt.

Living in Arizona presents several challenges when it comes to heat management. Of course cooler oil is better oil so why not install an oil cooler? Which oil cooler? Well an  oil cooler has to obviously keep the oil cool, but at the same time it should not impede the flow of oil and result in an oil deprevation situation.

I chose to put together a custom oil cooler kit so that I could get the features I wanted; 

  • Good cooling capacity
  • Good flow rates - large sized piping (1/2" dia)
  • Long term reliability
The parts purchased were:
  • 11" x 8" x 1.5"  48-row oil cooler core ($70) with 1/2"NPT inlets
  • 20x1.5mm spin-on adpater (Permacool #116 ~$12)
  • Remote filter mount (13/16" thread, about $25)
  • FRAM HP-1 or PH8 or equivalent oil filter
  • Three  -10AN to 1/2" NPT adapters (straight)
  • Two -10AN to 1/2"NPT adapters (90 degrees)
  • One -10AN to 1/2"NPT adaptor (45 degrees)
  • Six -10AN reuseable hose ends (straight)
  • 12 feet (min) of -10AN stainless steel braided hoses (0.56" internal diameter)


-10AN  to 12"NPT adaptors (Straight)

Stainless steel braided hose

-10AN reuseable hose end

Spin on adaptor, 20x1.5mm thread

Remote oil filter mount 
Note: this type proved to be the most flexible as it allows for multiple configurations


48-row oil cooler with adaptors attached

The majority of the cost went into the aircraft quality hoses, hose ends and adaptors. A cheaper option would be to get barbed conectors clamped down by hose clamps.

Putting it together

The first task was to determine where to install the remote reservoir. There is hardly any room in the engine bay of a Honda so something had to go.

It does not rain much in Arizona so I opted to remove the windshield washer bottle and install the remote reservoir there in its place.

The adaptor fittings were first installed on the remote mount and then the remote mount was bolted to the frame of the car. One 40 degree adaptor and one 90 degree adaptor was used. The adaptor fittings should be used with teflon tape to prevent galling and improve sealing. Do not overtighten the fittings as the die-cast aluminium mount may crack.

Fittings on the remote filter mount
NOTE: that is an electric oil pressure sensor on the left (optional)

Location of the remote oil filter mount


Spin-on adaptor installed on the oil filter position.
Next, remove the oil filter. The spin-on oil filter adaptor is then installed on the back of the engine block where the old oil filter used to be.

Again, remember to install the fittings 
(both straight fittings) before putting the adaptor on the block. Treat the adaptor like the remote mount and do not overtighten the fittings.

Another view of the spin-on adaptor

The next task is to assemble the hoses. Carefully measure the lengths of hoses required to connect each fitting together. Remember to leave some slack so the hoses do not get crimped by an overly tight turn. A schematic of the oil cooler circuit is seen below:

The hoses have to be cut cleanly. To do this properly, you will have to tape up the hose and cut down the middle of the taped portion with a hacksaw. This prevents the hoses from fraying.

The hose ends can now be fit on the cut end of the hoses, according to the manufacturer's instructions.

Install the adaptor fittings on the oil cooler. I used one 90 degree fitting and one straihgt fitting on the oil cooler Next, install the oil cooler in a suitable place. I installed mine in front of the A/C condensor coil. The A/C condensor coil had to be moved back about 1" to accomodate the oil cooler. 

Finally connect up all the hoses according to the circuit above, fill up with motor oil (you'll need a quart or two extra) and you are ready to roll.

Before you start the engine, be aware that there is no oil in the system. To fill the system with oil, I dosconnected the ECU fused and cranked about 6 times, each crank lasting about 10 seconds with a 15 second break in between. By the 6th crank the oil pressure light on the dash went out, indicating that there was oil in the system. The ECU fuse was replaced and the engine was started.

Walk around and check for any leaks. There should not be any leaks if you have done it properly.


Oil cooler mounted in front of A/C condensor.

The A/C consensor was moved back with longer holders.



The installation of the oil cooler system proved to be very efficient in the desert heat. General temperatures have been reduced by more than 5 deg F (water temperature) on a 110deg F day. The system was tested out on the Hybrid Track day and it kept temperatures below 210 degrees even when running at full tilt.

Engine bay after install was completed

The completed installation


Click here for more pictures


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