Earl's 501ERL Oil Thermostat

Earl’s oil coolers are known for the ability to cool and the quality of their product. Well, this oil thermostat bypass is no different. Quality machining and part design is top notch. You basically have two options here when deciding on this setup: One is from Derale (which I also have on another vehicle) and the Earls design. What I like most about Earls design, is the fact that the unit will start bypassing oil at 160 degrees F, with the unit going full open at 180 degrees F. With the Derale unit, any oil temps below 180 F causes the unit to route 90% of the oil back to the transmission (or engine), depending on what you are using it for. And just a side note, I have bypassed all my vehicles radiators (all have auto-trans) and opted for this setup. For those that live in a cold climate (like I do), all is required is to let the vehicle run for about 5 minutes or so on those extremely cold mornings before driving. I have gauges set up on my vehicles that tell me the temp of the oil leaving the transmission and the temp of it after running thru the cooler.

Seems like nice unit , you will have to buy some fittings to make it work, I'll repot back in few months.

Buyer Beware.Even with using Earl's "O"- Ring boss fittings I still didn't feel comfortable in using this product.The fittings felt loose,I called Holley/Earl's which was really of no help,all they told me was what fitting I should use,I told I was using the advised fittings they replied there was no other help they could offer.

I just got this oil thermostat, and I am having a devil of a time finding the correct connectors. It is listed as having -10AN O ring fittings, but all of the -10AN O ring fittings I have bought: Frangola 494002-BL and Russell 670710, have fit very loosely and the O ring does not seem to be large enough to form a tight seal. I am having to resort to massive amounts of teflon tape and I'm not feeling real good about running this in an endurance race.