E30 / M20 oil cooler size?

[Patrick]

What size oil cooler have you fitted with an M20 2.5ltr engine? The one from the donor (325i Touring) is too wide to install properly and it?s getting on a bit.

Thank you,

Patrick
www.msportster.co.uk

[Patrick]

Re: E30 / M20 oil cooler size?

After some research it would seem that oil has improved in the last 20 years to the point where the engine may no longer need to an oil cooler. The solution is to use parts from a 2.0ltr M20 engine that didn't run an oil cooler. These fit right on and are a direct replacements for the parts that the oil pipes attach to on the 2.5.

I am going to try running without a cool to start with and see how it runs.

[r.norman227]

Re: E30 / M20 oil cooler size?

Hi Patrick - Myself - I would be worried about ditching anything that cools the engine. There's not a lot of space under the Marlin bonnet for air to circulate and anything that helps keep things cool has gotta be good!

[Patrick]

Re: E30 / M20 oil cooler size?

Hmmm, not such a good idea then... I have left loads of space in front of the radiator so I have room for a cooler.

The other option I've read about was an oil/water intercooler but Ive not been able to find out much specific information on how to do this and what parts would be needed.

[h_m_cumming]

Re: E30 / M20 oil cooler size?

The general reccommendation is that the oil temp. should not exceed 80deg.C, although I suspect most modern oils and engines exceed this. Oil cooler thermostats are set to open at 80deg so the biggest cooler you can afford and fit makes sense with a thermostat as the oil will never exceed the thermostat temp. I know from the system on my Roadster that the oil temp. gauge never shows more than 80deg. and the oil pressure is always well up even after some long hard runs, this with a 10 row cooler, 2l Fiat, 150bhp.
Hope this helps, Hugh.

[Patrick]

Re: E30 / M20 oil cooler size?

Yes that's good, gives me something to aim for thank you.

I've been eyeing up the ones that Europa Spares sell.

Thanks,
Patrick

[h_m_cumming]

Re: E30 / M20 oil cooler size?

One thing to watch if you fit an oil cooler is to make sure the connections are at the TOP. This stops any airlocks forming in the unit and ensures an efficient transfer of heat.