Monday, February 7, 2011

Upgrading the Lotus Esprit S1 Oil Cooler & Lines

The old oil cooler lines in my Esprit were upgraded with new ones. It took me a while to figure out the thread pattern of the oil cooler and oil inlet on the engine. They are not AN, rather 5/8 BSP (hopefully that helps someone doing the same thing!). I purchased a set of four 90 degree fittings, oetiker clamps and enough 5/8 ID hose for the job. In all it took about 30 minutes to measure, cut, and set everything up. I purchased the lines and fittings at Pegasus, which is a US based automotive racing supply Web store.

The old oil cooler assembly was fine but pretty badly deteriorated. Time to renew!

The new oil cooler hose, 5/8 ID and good for 250 PSI.

The new fittings weren't cheap but I was limited in options to replace the old ones.

My existing oil cooler was in excellent shape so I had it chemically cleaned and refinished.

After having assembled everything, the oil cooler and oil lines are looking like new again.

I'm opted for the Mann filter, part number W920/17.

The oil filter adapter after having bead blasted the aluminum casting and replaced the rubber gasket.


  1. Nice work - the cooler looks great, but Lotus Esprit experts agree that the stock cooler is practically useless because it is too small and located in the right rear of the (hot) engine bay. They tell me it is better to get a newer (larger) after-market oil cooler and relocate it to the front of the car in the cool air flow. But if your goal is to have the car as stock as possible the original oil cooler is the way to go.

  2. Thanks for the tip. I'm probably going to keep everything origninal as I live in a cool climate.