Remote Oil Filter and Oil Cooler Setup
By Tom Moxey
I've spotted persons interested in my filter/cooler set-up, so here it is.
OK I admit it !! I did sorta steal this set-up from a SCCA GT-4 Sentra. Before I begin, let me tell you the results of my system set-up. The job is not real easy, but has proved to be beneficial. The use of 10AN hose and fittings were a perfect match to the system. As far as pressure loss none. As far as multiple points of failure, where ? If done right, this stuff is rated at 1000psi and is nuke-proof. I'm more than pleased with my results. Care should be taken to NOT over engineer an oil cooling system. The cooler specified here is not overkill, it's modest yet very effective. The cooler gets extremely hot which tells me it's working great !!
This is how it goes . Based on my aged memory, so bear with me on this.
Parts to buy:
The first thing we gotta do is loosen the PS pump, as loose as it can get, slip off the belt to get additional room. There is a bracket that supports the intake plenum which must be removed as well. All these bolts are a PITA to remove/loosen, so have patience. You can now remove the filter from the filter bracket. Loosen and remove the filter bracket ass'y. Remove the oil sender switch. Don't lose the two O-rings BT the bracket and the block. Clean off the surface on the block w/ acetone and a toothbrush until spotless.
Now the fun begins. Clean up the piece then put it in the vice. Fetch a hacksaw yes, a fine tooth hacksaw. Cut off the head. Do it in such a fashion as to leave the tubes as long as possible. The cut will be at an angle. You'll see what I mean once you scope it out. Yes, the internal oil bypass gets removed, not any problem unless you're one of these people that NEVER do an oil change. The bypass is there only to provide an oil route past the filter when it becomes COMPLETELY clogged with dirt. Most of us do mucho frequent changes, so this is a non-issue. The other piece excluded from my set-up is a thermostat. A thermostat would provide a cooler bypass route until operating temperature is reached. I opted not to use one because my '91 Classic isn't a daily driver. If it was I might consider one. So, the install of a thermostat is not covered here.
Once the head is cut off it will reveal the two tubes. Establish the flow direction at this time. LABEL THE TUBES. The return path is through the CENTER of the filter. With the finest file you have, clean the surface of the tubes. Also, remove the material BT the tubes down about a ½" or so and polish up the surfaces so you are looking at two distinct, clean tubes. The two 10AN weld fittings get attached to these points. What you have to do is attach a couple of straight 10AN fittings to these weld fittings to insure they have room to be spun on once the welding is done . Your screwed if this gets messed up, so triple check the set-up before the welding takes place. The alignment is perfect if the tubes were left at maximum length, thus the reason to cut off the head as close as possible. Now weld up the pieces, I found a great local speed shop with an expert TIG man. True artistry, that's what we're looking for here. DO NOT re-mount this piece yet.
Now you've got to locate the cooler and filter head. The filter head fits nicely behind the passenger side headlight BT the coolant reserve and the inside fenderwell. Hose route is straight forward, right under the PS reserve. Take that piece of aluminum and put a 90 degree 1" bend at one end. Layout and drill the piece as to mount the filter up, connectors down. Install the NPT adapters into the new head with thread seal and mount the ass'y to the chassis. There's a nice square, flat surface next to the coolant reserve you'll see. Set the height of the head with the filter on it to insure hood clearance.
Now we mount the cooler. There is an ideal spot right in front of the radiator on the passenger side. I made little 1" square standoffs for the cooler in order to raise it up a bit and provide a clean mounting platform. I also dumped those worthless fog lights. Mount it right in front of that entire opening. Heavy-duty ty-raps through the offsets and around the internal bumper frame does the job nicely. You might want to put a piece of screening material in front of the cooler to protect in from stones etc.
We've got to fabricate the hoses at this time. Use a scrap piece of garden hose to establish hose lengths. The send hose from the block goes to filter head input (NOT the CENTER). Cut the braided hose to length, wrap the cut zone with masking tape so it doesn't fray. On one end mount a 45 degree 10AN and the other end a 90 degree 10AN. Now measure the distance BT the exit port of the filter head (center) to the oil cooler (left side of it facing the front). Cut the hose, one end gets a 90 degree 10AN and the other a straight 10AN. You can install this hose at this time. It runs thru the uni-body below the headlight. OK last hose. Measure from the far side of the cooler and the return port on the re-fabbed filter bracket. Cut hose and connectorize with a straight 10AN and a 45 degree 10AN.
Now, take the filter bracket and attach the 10AN 45 degree to 90 degree hose to it. The 45 degree end goes to the bracket send port. Don't fully tighten it yet. Now attach the other hose with the 45 degree end on it. It goes to the return side of the bracket. Now to check it out for clearances. From the top, lower the filter bracket into place. Have a friend help with this part of the job. Have him/her hold the bracket in place to establish the angle the connectors need to be attached at to clear everything. Once you do that, go ahead and snug up the fittings on the bracket and reattach it to the block, don't forget the O-rings. Go ahead and put the PS pump back on and everything you may have had to remove to get this job started!
Now attach the remaining hose connections. You should fill the cooler with oil before starting the car. An easy way to do it is through the exit port on the new filter head. Quad-check ALL FITTINGS before starting your car. Put an oil filter on at this time. Fram HP-4 fits great and has an internal check like the Nissan OEM filter.
That's it . Simple wasn't it. It may take a few seconds for full oil pressure to come up as we've got to 'bleed' the system of any remaining air, so don't freak out too quick. Keep in mind if you haven't paid strict attention to the flow direction and have them backwards, NO OIL WILL FLOW because of the oil filter check valve. Don't overlook this major issue.
The average cost of a set-up like this is about $250
Best of Luck,