External oil cooler kit? Options

[neilbardsley]

https://www.ebay.co.uk/itm/165865762191?mkc...&media=COPY

Is this kit compatible with the type 4 filter? Seems like pretty easy add on?

I would prefer a coupling that didn't use the external filter until 180f but can't find a complete kit.

[ChrisFoley]

In my experience on the race track, continuous operating at oil temps much above 225F was detrimental to oil pressure. Not sure if it was change in viscosity or larger bearing clearances or some combination of the two.

[Superhawk996]

In my experience on the race track, continuous operating at oil temps much above 225F was detrimental to oil pressure. Not sure if it was change in viscosity or larger bearing clearances or some combination of the two.

Within limits viscosity can be addressed. When I used to crew, it was common to run thicker oil to account for the viscosity loss. The problem was on cool mornings that meant heating the oil sump and the engine block before starting to keep from starving the bearings when oil was cold. It’s all just trade-offs.

Regarding gauge pressure - it isn’t the be all end all. As long as there is sufficient oil being supplied to the bearing, the hydrodynamic oil wedge will be maintained and the bearing and crank will be protected.

To put some numbers to this, if oil pressure is nominally 60 psi at 5000 rpm with 210F oil, and things get hot, oil viscosity decreases and oil pressure (gauge) drops to 50 psi, there will still be plenty of hydrodynamic pressure within the bearing to support the crank loads.

If on the other hand the supply pressure (gauge) drops to 25 psi at 5500 RPM, sure there is going to be a loss of the oil wedge and increased bearing and/or crank wear.

This is getting pretty far off topic into the realm of racing, high engine loads, and RPMs that most engines only see momentarily. I don’t mean to discount your observation on track.

However, track use shouldn’t be taken to be the same as street use of extend high speed driving at legal posted limits plus some long arm of the law fudge factor.

Anecdotally my 1st 914 was a 1911cc and I used to cruise at 80-85. Midwest summer temps into 90s and low triple digit are the norm. Stock oil cooler. That engine ran 100k miles. Was it down on power at the end? Sure, but what engine isn’t by then.