The TYPE I oil pressure and temperature adapter block allows for the easy installation of aftermarket gauges in your RX-7.

The stock engine oiling systems found on both the non-turbo and turbo rotary engines are exceptionally good and entirely adequate for even mildly modified engines.

Oil pressure in a stock engine ranges from 20 to 40 psi at idle RPM. Above 3,000 RPM oil pressure is approximately 70 PSI (1993-95 - 110 PSI max, RX-8 80 PSI Max), but may drop about 10 PSI above 4,000 RPM due to oil foaming. Oil foaming results when oil, as it is cooling the rotors, thrashes inside the rotors and traps air.

As a general rule, oil pressure should be increased as the horsepower output and engine RPM increase. As horsepower and RPM demands increase, it is beneficial to have higher oil pressure between the shafts and bearings to prevent possible catastrophic contact between spinning components. Additionally, as oil pressure is increased, flow rate also increases; hence, more oil is available to cool the bearings and rotors.

To obtain higher oil pressure from a 1995 and earlier engine equipped with a conventional oil pump (as opposed to a "dry sump" pump), several actions are desirable. First, leave out the front cover gasket, and use only the RX-7 front cover-to-front housing O-ring (Mazda P/N N231-10-174), which is thicker than previous models. Be sure to use "silicone seal" in place of the gaskets on the sealing surfaces of the front cover. This process reduces the chance of leakage from the oil passage between the front cover and front housing. Next, select an oil pump size suitable for the job.

For street high-performance use in 1979 and earlier engines, 80 to 85 psi can be obtained by shimming the stock rear oil pressure regulator 1/8". For 1980 and later cars, the regulator cannot be disassembled, so the best choice is the Racing Beat Street High-Performance Rear Oil Pressure Regulator. Beyond this pressure level, use the factory race pressure regulator, which is set at approximately 105 to 115 psi. Using the race regulator for street use will accelerate wear on the oil pump.

Beginning in 1979, Mazda discontinued the oil pump chain tensioner. Although the tensioner does no harm, it apparently does no particular good, so it can be left off for simplicity if desired.

Oil temperature is critical in rotary engines. Oil temperature entering the engine should never be allowed to exceed 205°F. While many factors affect oil temperature, oil cooler size and location are very important to consider. Roughly one-third of all engine heat rejected via the water and oil cooling systems goes out through the oil cooler. The oil cooler should get about one-third of the total cooling air flow.

Another factor that inhibits heat transfer from oil is air bubbles that become trapped in the oil. Air acts as an insulator and reduces heat transfer. While rotaries have little tendency to foam the oil through windage in the oil pan, as do reciprocating engines, air is mixed with the oil as the oil moves through the rotors. By slowing the oil as it returns to the pan, air is allowed additional time to separate from the oil. Our Oil Baffle Plate is designed to perform this function.

Changing Engine Oil With Regards To Engine Oil Coolers - While it is true that during a routine oil change the oil in the lines and coolers is not changed during normal oil change, it has not proven to be a problem. The quantity of unchanged oil is not large, so even though it dilutes the fresh oil, it is not a serious factor. In any case, we would not recommend disconnecting lines to change that oil due to the risk of leaks. As a practical maatter, you could increaase the frequency of changes, but again, in our experience it has not proven to be necessary for the life of the engine in street use.

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