Oil Cooler Cap

Race tested an proven oil cooler system for the M50, S50, S52 series engines.

Design features include:

• -8AN o-ring ports to provide a leak free fitting without the use of Teflon tape or sealant used by other oil cooler caps.

• Viton o-rings are used throughout to maintain function and sealing in a high temperature oil environment.

• Use of the stock filter cap bolt to reduce cost and simplify installation.

• An internal sealing mechanism to direct oil flow through the oil cooler and through the filter.

• 1/8" NPT side port for external oil pressure gauge.

The cap is machined from 6061-T6 billet aluminum and hard coat anodized for scratch resistance and to keep the oil cooler cap looking good for years.

To the best of our knowledge, this is the only oil cooler cap available with an actual sealing mechanism to direct the oil flow through the cooler lines and then through the oil filter.  Other cooler caps do not provide this seal and therefore the external oil coolers and lines act as a "balloon".  The lines and cooler are pressurized, but oil does not flow through them.  Flowing oil means it is being cooled and not just acting as an external reservoir.

We have run an oil cooler cap flow comparison testing with a Hedland 0-5.5 GPM flow meter.  The difference in FLOW between our oil cooler cap, the euro M3 oil filter housing, and the competition was astounding!

Recent flow testing shows that the oil cooler cap will outflow the Euro M3 Oil Filter Housing by more than 80% at the same, pressure, RPM, and oil temperature.  That is a huge difference in flow.  In the upper RPM range, there is nearly a 100% improvement in flow from the RallyRoad oil cooler cap when compared to the Euro M3 oil filter housing.  This is a worthwhile and cost effective upgrade.

Each oil cooler cap assembly also comes with a lower filter sealing ring and a new BMW MANN Oil Filter Kit.

Please choose black or blue -8 AN fittings.  -10 fittings are also available.