Oil Thermostats| Grassroots Motorsports forum |

johnp2 New Reader
10/12/12 4:28 p.m.

Hey Guys,

Been doing some searching on this and cannot seem to find an answer. Perhaps the great minds at GRM can help me out.

I see several of these oil thermostats that have two inlets and two outlets. Is there a specific reason for this? Would it be much neater and more of a simple setup to have a single inlet and single outlet style? That way the thermostat is just located in the line heading to the oil cooler?

Perhaps I am missing something. Any help is greatly appreciated.

Thanks

Nashco UltraDork
10/12/12 5:02 p.m.

These are typically added to an engine externally. If you have a line coming from the oil pump high pressure side out to the thermostat, when the thermostat is closed, the oil immediately goes to the "return" side. Once the thermostat opens, the oil goes to the cooler, then returns through the loop. You can't just have a single in/out, otherwise when the thermostat was closed you'd have no oil flow back to the engine. If you run a parallel path (allowing flow to the engine when the thermostat is closed with a single line in/out), then when the thermostat opens you don't have any reason for the oil to flow through the cooler.

Of course, when these are built into an engine from the start, the pressure feed and return to engine are internal and you don't see so much going on externally while still accomplishing the same thing...however, that's quite rare to have a built in oil thermostat. These days, much easier to include a water to oil heat exchanger and let the radiator and coolant thermostat do the temperature management part.

Bryce