DIY Oil Cooler on a NA 350z HR

[Lrn2Go]

I've seen a bunch of DIY's on how to fab up an oil cooler and place it on a Z with F/I and aftermarket bumpers... but what if you have an HR with the stock bumper? Hopefully this will help you out. First off... I want to give props "Ttschwing" and his fabrication of his oil cooler on his 370z. I used his information as a base guide, then made my own changes to make it work for the 350z HR motor and setup.

Also... since you're effectively tapping into the life-blood of your engine, I'm simply sharing my experience and in no way are at fault should your experience not be the same as mine.

Car: 2008 Nissan 350z with VQ35HR

Difficulty rating from 1(Stickers) - 10(Engine Rebuild): 6

Time: 2+ hours

What to expect: Not super "technical", but takes some ability to follow instructions and some base mechanical knowledge. I did not remove my front bumper, but some things may be easier if you chose to do so. A lift will keep you off the ground, but I did mine on some jack stands.

Reason: To save money from pre-made kits. To use 10AN lines instead of 8AN lines (what most kits come with). To allow for ultimate customization to fit my needs.

Tools you need:

Screw Driver (flat head and phillips)
Hack Saw w/ fine blade (or a cutting wheel works too)
10mm Socket
1" Socket
2x Crescent Wrenches
1/4" and 1/2" Ratchets
1.25" Hole Cut Drill bit
Drill
Teflon Thread Tape
Other Tape (Painters, Scotch, Whatever)


Optional:

Tabel-Top Vice
Zip Ties
Pry Bar
Pen-Magnet


Okay... now the parts you'll need. You'll be able to buy all the lines, fittings, cooler, and thermostatic sandwich plate from Racer Parts Wholesale (http://www.racerpartswholesale.com/). The rest can be had at your local hardware store.

Parts List:

1x Mocal 1/2" BSP x -10 fitting - MOC-2BM810A
1x Mocal Sandwich Plate- 20mm Thread - MOC-SP1FT
1x TRU-Cool 24 Row Racing Oil Cooler - TRU-L7B
2x Aeroquip 90 Degree Male Elbow, Alum. -10 to 1/2" Adapter - AER-FCM2039
1x -10 Aeroquip Stainless Steel Braided Hose, 10' section - AER-FBA1000-10
2x Mocal Reusable 90 deg Hose End -10AN Red/Blue - MOC-F90-10
2x Mocal Reusable Straight Hose End -10AN Red/Blue - MOC-FS-10
10"x2" Steel or Aluminum Plate
Bolts, Nuts, and Locking Washers
2' of 1.25" clear rubber tubing


Total Cost: About $315 ($300 cooler parts, $15 for bracket and tubing)

Okay! Let's get down to it...

http://img863.imageshack.us/img863/8770/oilcooler0312110000w.jpg

Remove your lower pan cover, drain your oil and remove your filter.

http://img684.imageshack.us/img684/5439/oilcooler0312110001w.jpg

Assemble your thermostatic plate and your fittings.

http://img217.imageshack.us/img217/1730/oilcooler0312110005w.jpg

http://img847.imageshack.us/img847/3217/oilcooler0312110007w.jpg

http://img141.imageshack.us/img141/7784/oilcooler0312110008w.jpg

Now we decide where we want to mount the oil cooler. I decided I wanted to mount it on the drivers side in front of the radiator. There was the most room here and, while I played around with the idea of mounting it to the actual aluminum bumper, I didn't like how it looked and how I'd have to run my lines. I ended up choosing this location because of the pre-existing holes that we could use for mounting.

http://img508.imageshack.us/img508/5306/oilcooler0312110010w.jpg

Next... wrap your 90 degree elbows with your teflon thread tape (only on the cooler side! I did NOT use the tape ANYWHERE ELSE!!!) and screw them in. Use your cresent wrench to tighten them down but don't tighten it down too hard to where you may damage the threads. I kept the inlets pointing to the "right", where I eventually decided I would run my lines. Now, let's see how our cooler is going to look mounted up here and take some measurements.

http://img837.imageshack.us/img837/8008/oilcooler0312110012w.jpg

As it turns out, a 10" by 2" piece of metal would work perfectly. Now we grab our metal we're going to use for our bracket. I chose an aluminum strip that came in a 2" wide version that I got from an Ace Hardware and measured 10" out.

http://img835.imageshack.us/img835/8010/oilcooler0312110009w.jpg

You mock it up and mark the original holes where you'll put your screws in the cooler. You'll drill these spots out with a drill and whatever size bit that matches your bolt size (I used 5/32nds for mine).

http://img97.imageshack.us/img97/7439/oilcooler0312110013w.jpg

Now mock it up the same way to the holes in the lower radiator housing and drill them out. I unhooked the top-locks for the radiator to give it a little more freedom of movement. They just twist... so turn them in the direction indicated as "unlock".

http://img862.imageshack.us/img862/6008/oilcooler0312110018w.jpg

After that I used a pry bar to slightly lift the radiator (held in place by the sway bar) and a pen magnet to guide my bolts through the holes and bolt the cooler up to see if I liked how it's looking.

http://img339.imageshack.us/img339/2185/oilcooler0312110019w.jpg

http://img25.imageshack.us/img25/9897/oilcooler0312110020w.jpg

Next, I took it back apart and then hit the bracket with some flat black paint. I didn't use anything special... just regular flat black. I figure it won't get very hot or anything, so it shouldn't need anything special.

http://img707.imageshack.us/img707/6358/oilcooler0312110015w.jpg

After that dried, I mounted it all back up one last time, using lock-nut washers and tightened them all up.

http://img62.imageshack.us/img62/924/oilcooler0312110021w.jpg

At this point you should use your 1" socket (should be thin-walled) to tighten down your thermostatic plate (follow the instructions included with it where you tighten till it the plate seals, then 3/4 a turn more). Once it's in place you can get an idea for how you want your lines to run. You can simply mock up how they will route by running the lines along the approximate path you were planning on using, then mark the line where it needs to be cut. I ran my lines from the plate, along the front of the engine, around the side (in the fender well), then back to the front cooler (scroll to the end to see a picture of the routing I used). You're going to have to cut your single 10' section to create your 2 lines. Here are the proper instructions for line creation, which I followed. I used my 2 crescent wrenches to tighten and assemble my hoses.

http://images18.fotki.com/v457/filem1cR/f0613/5/7305/7542048/anfitting.jpg

http://img6.imageshack.us/img6/6549/oilcooler0312110023w.jpg

http://img215.imageshack.us/img215/823/oilcooler0312110024w.jpg

http://img5.imageshack.us/img5/9438/oilcooler0312110025w.jpg

http://img821.imageshack.us/img821/1888/oilcooler0312110026w.jpg

Next, unhook the plastic pins under your car's drivers side wheel-well where it connects to the front bumper. You don't have to remove the whole wheel well housing, just enough to get it out of your way. Once it's out of the way, there's a small plastic piece that it connects to up near the side of the engine. I didn't take a real good picture of it (I was starting to get tired at this point), but this is what the panel looks like after you've drilled holes in it with your 1.25" hole drilling bit. You'll use this for your lines for routing and support.

http://img59.imageshack.us/img59/1006/oilcooler0312110027w.jpg

Now... I re-mounted that plastic piece and used my drill and bit to drill through this reinforced plastic piece in the front (make sure the hole is pretty low for the closest line), then routed the first line.

http://img291.imageshack.us/img291/6417/oilcooler0312110028w.jpg

Because stainless steel will (with the movement of the motor) saw it's way through just about anything... any place the lines may come in contact with one another, metal, or plastic... I took my clear rubber tube and covered that area with it, then used zip-ties to keep it in place. When it was all said and done... my line routing ended up looking like this...

http://img839.imageshack.us/img839/4215/oilcooler0312110030w.jpg

After this... put your filter and plug back in and add your oil. I put in about 5 quarts and started the car for just a second, then shut it off (we don't want to starve the motor from oil if there's a problem). It's going to make some "squish" fluid noises as the air clears out of the cooler, so that's normal. Check to make sure you have no leaks. If everything's clear... make sure oil is showing up on the dip stick (won't necessarily be up full yet, but I hadn't set the car back flat yet so I knew my readings weren't going to be right yet).

Now... start the car again. This time we're going to let it run (at idle) and warm up. Keep watching your lines. After it's warm... if you still have no leaks, turn the car off, bolt all your plastic under-tray and fender well bolts back up and lower the car. Check the oil again and top it off. My car took about 6.5qts of oil after the addition of the cooler, but yours may vary.

Take your car for a test drive! Be easy and stick close to your house/shop and keep your eye on that oil pressure. If everything looks good after a while, check the fittings one more time. If they still look dry... then you should be good to go! Take it out, give it hell, and enjoy your added cooling!
:trogdor:

[C-unit]

how much is the mocal sandwitch plate?

[Lrn2Go]

how much is the mocal sandwitch plate?

I gave you everything you needed to find it on the website (for the most current price)... but when I ordered it, it was $86.95 plus shipping.

[DeleriousZ]

Great writeup man, props!

[C-unit]

I gave you everything you needed to find it on the website (for the most current price)... but when I ordered it, it was $86.95 plus shipping.

thanks..i must be blind...:picardfp:

[Lrn2Go]

thanks..i must be blind...:picardfp:

It's all good. There's a lot of text and pictures to scroll through there. :D All the info (web site, parts, and part numbers to look up on the site) are all in this section here...


Okay... now the parts you'll need. You'll be able to buy all the lines, fittings, cooler, and thermostatic sandwich plate from Racer Parts Wholesale (http://www.racerpartswholesale.com/). The rest can be had at your local hardware store.

Parts List:

1x Mocal 1/2" BSP x -10 fitting - MOC-2BM810A
1x Mocal Sandwich Plate- 20mm Thread - MOC-SP1FT
1x TRU-Cool 24 Row Racing Oil Cooler - TRU-L7B
2x Aeroquip 90 Degree Male Elbow, Alum. -10 to 1/2" Adapter - AER-FCM2039
1x -10 Aeroquip Stainless Steel Braided Hose, 10' section - AER-FBA1000-10
2x Mocal Reusable 90 deg Hose End -10AN Red/Blue - MOC-F90-10
2x Mocal Reusable Straight Hose End -10AN Red/Blue - MOC-FS-10
10"x2" Steel or Aluminum Plate
Bolts, Nuts, and Locking Washers
2' of 1.25" clear rubber tubing


Total Cost: About $315 ($300 cooler parts, $15 for bracket and tubing)


Let me know if you have any other questions!

[slamn240]

do you notice a difference on the response of your motor with the added cooler? for example since your oil is cooler, the oil pressure shouldn't drop that low as before and should feel like its more responsive like it does in the cold mornings right when you get on the freeway. Its that stronger pulls you get merging on to the freeway. i hope you can understand what im saying because i suck at explaining myself. example that im thinking about...... its like the extra boost that vtec gives a honda, pressurized oil level makes it faster....

[Cookie08z]

I know this is bringing up an old thread, but I thought that this deserved a response to clarify what Slamn240 posted.

First of all, fantastic write up and a worthwhile mod especially for tracking.

I tuned Honda's for about 10 years and am a mechanical engineer, so I felt I should clarify the VTEC and oil pressure / temperature statement. This is just for informational / education purposes.

First off VTEC = Variable Valve Timing and Lift Electronic Control. It was the first Variable Valve Timing system and was released on the CBR400 in 1983 (wiki). Because of the differences in fluid and combustion behavior at low RPM and high RPM a low(small) lobe is used for the lower RPM and a high (large) lobe is used for high RPM.

This is the best picture I could find to show the 3 lobes, the largest being in the middle.
http://www.theoldone.com/articles/badtothebone/vtec_dowel.jpg

Oil pressure IS a factor in VTEC, but only because the increase in oil pressure actually activates the large lobe on the cam. The oil pressure alone cannot increase response. A sharp spike in oil pressure forces a pin into position and locks both intake valves together with the large lobe, and the same happens with the exhaust.

This link is by far the best video demonstration I have come across, it is using the s2000 as an example, but all VTEC works in basically the same way.
http://www.youtube.com/watch?v=SONyajrvWOMhttp://

With all that, by cooling the oil a bit will increase the fluid density because as things get hotter the molecules separate more, which decreases density, when coupled with viscosity of oils this will "thin" the oil at higher temperatures, and "thicken" the oil at lower temperatures. If we cool the fluid then we thicken up the oil when compared to not cooling it. This will actually increase drag on the crank and connecting rods and actually would effectively decrease response, but the difference in this case is so small that it will not be noticable to the butt dyno, and not really even worth mentioning when on a real dyno.

Going back to the greater response on a cold morning, this is due to the air being cooler, which we just covered will decrease the spacing of the molecules in the air, which means we can get more oxygen molecules in the same volume of air. In order to ignite the fuel we need oxygen, so the more oxygen we have available the more fuel we can ignite. The ECU here will compensate for us and inject a bit more fuel, because it is attempting to maintain the Air/Fuel target that is input into the ECU. Also, there usually is a bit of unburned fuel in a combustion cycle, especially when they are tuned after the factory, so this increase in oxygen increases the combustion of this normally unburnt fuel. This increase in fuel combustion creates a larger explosion, and therefore more force is transferred through the pistons to the crank.

I'm relatively new to this site, but I'm sure some of this is covered somewhere in the tech sections as well. Again, I thought it would be a good piece of info to have.