And because one good 'how I did it' post deserves another, here's how you put the 5S-FE cooler on an '05 Elise:
0. Why am I doing this? Because the Lotus solution for EU/UK/AUS cars is kind of expensive to add to a US car at this late date and I had the functionally equivalent 5S-FE part laying around. If you want to see the factory solution for 2ZZ-GE oil cooling, it looks like this:
. MWR sells the bits you need for the stock system, and not-a-number shows a variation of the install procedure above.
The procedure I followed is modeled on this one for a 7th generation Celica with 2ZZ-GE: How to: Oil cooler on a 7th gen
1. Get your cooler and center bolt (with relief valve) from a 5S-FE. The cooler I used is part 15700-88360 - COOLER ASSY, OIL, with center bolt 15690-88360 - VALVE ASSY, OIL COOLER RELIEF. from a '92 Celica GT. All 5S-FE engines sold in the US came with a variation of this cooler, because the engine was the largest iteration of the engine and needed the cooler. Where can you find a 5S-FE? Four cylinder Camrys built 1994-1999, Celica GTs built 1990-1999, and some RAV4s in the same year range. I recommend a tired, high-mileage engine from an auto trans car as a source so you know it probably didn't throw a rod.
Overview of the cooler and its associated plumbing (on a JDM SW20 MR2 in this case): ENGINE OIL COOLER / toyota | part list?JP-CarParts.com
2. Get two 90 degree 5/8" water hose elbows. The Toyota part is 16295-74010 (identified as a bypass hose in the Toyota diagrams), but there's nothing special about it, and you'll be cutting it shorter than supplied anyway. I'd recommend just getting two each of one of these from a vendor: DAYCO 80400, CONTINENTAL 63806 or GATES 28466. You'll also need hose clamps to fit. I use the spring clamps Toyota uses - they come free with the cooler and are an easier fitment in the tight Lotus engine bay than a screw clamp. You will need a total of six hose clamps - two come on your Lotus-supplied hose (holding the aluminum U-tube in, and four come with your cooler.
3. get two brass 5/8" double male barb water hose repair kits. Yes, you can go over the plumbing section and get the same thing branded differently for more money, but why? I used two of these: https://www.lowes.com/pd/Yardsmith-Y...ender/50328351
. These will be replacing your aluminum U-tube and connecting the 5/8 elbows to the existing Toyota supplied hoses on the engine. Throw the cheap hose clamps in the goodie drawer for some other project.
4. Order these: 90301-52006 Oil Cooler Seal, 15785-35010 Oil Cooler Gasket, 90201-22010 Relief Valve Seal. They're less than $5 ea.
5. Get a 3/4" x 16 TPI threading die and any tools you'll need to use it properly. You'll need this to extend the threads on the center bolt.
1. Clean up the cooler. It's all welded stainless sheet steel, so you can be pretty aggressive in your cleaning efforts. It'll have some baked on cruft on it because the filter mount on an S engine is below the header and beside the catalytic converter and down pipe. Clean up the center bolt, too, but this won't need much help.
2. Prepare for an oil change on the Lotus. Remove the filter sandwich block. Disconnect the cooler lines from the block. Drain cooler lines of oil. I used compressed air to blow oil out of the entire cooler circuit. Messy, but removed a pound or two from the car. During work, you might find it beneficial to have them dangling to give a bit more room for hands and tools. At completion, seal the ends of the lines or connect together. I zip-tied the lines to the front engine mount in one case and a radiator hose in the other case to keep them out of the way of things.
2. Scribe a line on the center bolt where the inner seal on the oil cooler touches it. You don't want any threads cut on the bolt beyond this line.
3. Thread the center bolt up to the scribed line. I found that the back of my threading die had a steeper pitch than the front (cutting face) and so I could get properly sized threads a little closer to the seal with that. Cut off about 1/2" of the threaded end of the bolt and chamfer the threads.
4. Wash the swarf off of everything. and test fit on the engine The cooler adapter bolt in the engine block has about 5mm of recess relative to the filter mount. It looks like it won't clamp up properly, but it will.
5. Drain the engine coolant from the block drain cock. You don't need to drain the radiator, particularly if you have the nose of the car pointed down a bit.
6. Undo the spring clamps on the aluminum U tube and push them up the hoses above the tube. Poke something pointy (I used a machinist's awl) in the tube-hose interface and wiggle around to break the seal between the U tube and the hoses. The small shower of coolant you'll get is the feeling of success. Wiggle the U tube out of the hoses.
7. Fit the hose barbs to the cooler hoses on the engine. Pick your cooler rotation angle for best hose fitment and cut the new hose elbows to fit between the cooler hoses and the cooler. Clamp the hoses to the barbs. Remove the cooler and wash it and the center bolt again. Once dried of solvent (cleaning solvents eat seals), replace the inner and outer cooler seals with the Toyota parts you bought. Bolt it all to the engine using the new center bolt washer. Torque to 58 ft-lb. (from: https://www.slideshare.net/IsaacTorr...gerepairmanual
, matches the cooler bolt torque on 5S-FE). Clamp hoses to cooler.
8. Refill cooling system and test run, checking for coolant and oil leaks.
Your pics below are:
1. test fitting cooler before cutting elbow hoses to fit
2. Threaded and shortened center bolt/bypass valve
3. Shortened bolt inserted in cooler. Threads originally stopped about 1/2" before the inner seal on the cooler.
4. view of cooler inner and outer seal as removed from donor engine
5. Lotus U tube, 5/8" brass hose barbs test fit into OE 5S-FE cooler hoses to validate fitting size