One other thing there to add to Marks comments is that not a lot of engines have such high oil pressures as the s2k, and it's not unknown for the cheap chinese copies to balloon if they're used with that kind of pressure, so be careful what you choose for a F20C. I will say I've had Setrab, Motul's and the current Claas unit up to 150psi with no issues though.

 

This is a good point, i have had alot of hassle with coolers on the S2000, especially niggly leaks which i dont like having. The main thing with the S2000 is its huge flow rate, a 13 row cooler at 60litres per minute will cause alot of restriction, if you really opt for a cooler then go with a few more rows so it gives the oil another path to flow through when its at peak oil flow. I know if i ever do a trackday only build in the future then i will go with the Laminova again, i know its expensive but its a top piece of kit, robust and tough.

RX7 and RX8's are well known for destroying oil coolers because of high pressure spikes.

I think when you fit an oil cooler you really have to keep on top of it, check the hose regularly for any damage or leaks

Buggy one question, do you struggle to get AN fittings to reseal again after dismantling? i have got some soft aluminum conical seals to fit to mine as it drips a tiny tiny amount of oil during operation. Not alot but its annoying as i want the engine clean. The conical seals seem to get a good write up and i know some people even use them on brand new fittings. I dare not tighten the fitting anymore as i know you can put them out of shape quite easily.

 

For a car without an oil cooler what makes you think, 'I know, I need an oil cooler'? Is it the addition of some equipment that demands it? or the hammer you expect to give the car on track?

Why would one fit an oil cooler?

 

In an S2000 you don't really need one (IMHO) as the cooling is generally very good indeed.

In a rear-mid-engined car like your Lotus, I imagine the cooling is not as good (especially seeing how complicated your radiator install was) so an oil cooler might be a good idea.

This video shows just how good an S2000 is in the heat, and also note how the rear-mid engined NSX suffers:
[media]http://www.youtube.com/watch?v=ZBGaqLQBnUM#t=362[/media]

 

Hard use, high engine bay temperatures, mods for more power, etc.
You have to remember that standard engine setups usually aren't designed to cope with the constant heat from long track/race use at high rpms, which is what tends to overheat oil.

For us, our racing all tends to be low average speeds - so poor cooling airflow - yet very high full throttle situations, and the tight packaging required means air temperatures around the engine block are high, so little heat rejection there, hence we end up fitting rather large oil coolers, the current oil cooler on the buggy isn't far off what most people would use for an intercooler

 

Oil temperatures is the main reason for an oil cooler, i regularly used to see 130c after about 15 minutes on track. If you can keep the edge off of the heat then your giving the engine and the oil an easier life. The S2000's oil system does get too hot after a few laps, the OEM cooler will only start to work if you back off for a lap and lower the revs so that the oil stays in the donut cooler long enough to have any effect. You would have to be an insanely fast driver to cook the S2000's oil on the road as it requires long pretty much constant vtec engagement to get lots of heat into the oil. On the track the temperatures rise very quickly.

I always think to myself that you want to limit how much abuse the engine gets and if you can cool it down via a decent radiator and an oil cooler then its not a bad thing. I find lifting off for an entire lap to get the temperatures down to 110c and then going hard on it again quite frustrating. I guess its really what you want out of the car. I would never fit one on a road car unless you were having high temperatures. The highest i ever saw on the road with my car was 109c which is well within what the oil can handle.

Fitting an oil cooler also has its downsides

- Oil pressure drop
- Increased risk of failure of hose or cooler
- Potential to overcool the oil if the cooler isnt controlled correctly via a thermostat.
- Cost

Its definitely not a fit and forget item thou, you need to keep an eye on it because 100psi will make a big mess if it finds a tiny leak and a hot engine bay and oil don't mix well. There has been lots of stories about S2000's catching fire due to loose oil filters.

I did think about trying one of these out

http://www.ebay.co.uk/itm/Subaru-Imp...item3f272d75da

Its larger than the OEM Honda unit but the cost is too much to justify trying it and then it not working.

 

An alternative to that which I've seen used before on some engines was to to put 2-3 OEM exchangers together and plumb them in parallel. But I'm pretty sure there's not enough room in the S2k to do that, as your oil filter ends up 4 inches further out.

 

Sounds wonderfully Heath Robinson!

The 'Lude's PAS cooler was a long, finned pipe in front of the radiator. Mild steel, so prone to corrosion, though.

I had an idea about putting a more convoluted (or finned) S/S pipe to the standard water manifold, just to lose a bit more heat.