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The Care of a Rotary Engine: RX-7s and RX-8s

The Care of a Rotary Engine: RX-7s and RX-8s

Great do-it-yourself tips to help you maintain a rotary engine.

Like your rotary? Well then you probably want to keep it alive.

These are some basic tips and maintenance procedures that will keep your rotary running smoothly and strong for many years…

Oil Change

This, as with all motors, should be one of the most important maintenance procedures. The oil should be drained and changed with oil of proper viscosity, along with a new filter every 5,000 miles or 5 months (non-turbo), and every 3,000 miles or 3 months for turbo rotaries as is recommended by Mazda. However if you want your rotary to last for a long time and keep it in top shape, change it every 3,000 miles or 3 months or so.

Warning! It is important that the oil is changed with non-synthetic mineral motor oil. The use of synthetic oils will cause damage to the apex seals of rotors and all other seal in the engine.

Synthetic motor oil= artificially created, non-natural, chemically produced motor oil to help lubrication in cylinder motors.

Checking the Oil Level

This is just as important. The rotary is a high oil consuming engine. It is estimated to consume at about a pint every 1,000 miles, but of course like all engines, as it gets older the more oil it may consume so it is best to check more often. The oil level is recommended to be checked at about every fill up of gas if not at least once a month. For abnormal driving conditions (Racing, Drifting, Mountain driving, or over 100 miles a week) should be checked about once a month. If low or even depleted below the first bar it is best to top it off using NON-SYNTHETIC motor oil.

Check the Tire Pressure

You should do this at least once a month; to make sure your tires are inflated properly. Improperly inflated tires can cause the engine to work harder, decreasing fuel economy and putting more stress on the engine, as well as loosing power. Other effects could be abnormal wear in the threads also.

Checking Other Fluids

Although they are not really part of the engine it self, the brake, clutch, and power steering fluid should be checked at least once every month, and if below the full line top of with correct fluids of correct viscosity. The low fluid levels could cause wear and damage in its components.

Another major must check fluid is the coolant. Check the coolant level when the engine is cool, when the engine is hot the coolant is less in the reservoir since it is being passed through the cooling system. Add coolant of 50/50 mixture of coolant and water if below full line when engine is cool. Adding coolant to hot engine could cause damage to the system or the engine. It is also important to check the quality of the coolant at least once a year with a coolant checker found cheap at almost any auto store. What it is, is a eye dropper looking thing with little colored beads in it which tell you, with the amount of beads floating, what is the max heat temperature is. If the coolant is no good (usually last about 5 years) flush the system and fill with new 50/50 mixture of coolant and water. Flushing also helps clean the system of any damaging particles such as rust.

Checking The Belts

Most rotary engines have 3 belts. One for the alternator,  air conditioning compressor and the power steering pump, which is all connected to the eccentric shaft pulley (which makes the rotors spin). These belts should be checked at least once a month for any damage such as cracks, grease, being glazed, etc. Don’t forget to check under the belt as well, and if damaged have it replaced with a new one. A broken belt in the middle of no where can be a real pain.

Checking Spark Plugs

If you’ve been to the site where they show how a rotary works, you should know that the spark plugs play an important role in the rotary engine as it does with any other engine. Checking the spark plugs at least every 2-3 months or best if every month will prevent any spark plug failures and loss of performance, and make sure that the engines ignition works smoothly.

Things to Remember

  • Don’t forget NOT to use synthetic motor oil, use only mineral motor oil of correct viscosity.
  • Make sure the maintenance check is done at least once every 2 months if at the worst. Refer to the above section.

It is said that the Rotary is known to flood if started and turned off before normal operating temperature is met, or at least warmed. This is usually the case with old engines, but it is said that the CPU or computer injects a large amount of fuel during start ups and if turned off before this stage is over, not all of the excess fuel may not be used and left in the compression chamber. Flooding will not happen till the next time the engine is started when again goes through the start up stage and adds the excessive amount of fuel to the chamber which is already filled partly from previous use and this could cause flooding, causing the engine to not start. If in the case of a flood the cure for this is still being researched.

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Responses

5 Responses and Counting...

  1. Grant Boss

    July 18, 2007

    This article is horrible… You say the engine floods if it is started before it gets to operating temperature??? lol, How exactly are you going to get it to operating temperature without starting it? Also the engine needing to be warmed up has to do with the turbos, not the rotary engine. To get rid of the flooding problem all you have to do is slightly rev the engine before turning off the key to clear the rotors. Also you should probably talk about the apex seal needing to be changed, that is the biggest issue with these engines. You sir suck.

  2. Flack

    July 18, 2007

    I think he means if you start the engine and do not allow it to reach operating temperature the engine will leave more fuel in the engine, so, the next time you start it, excess fuel will be pumped into the engine along with the fuel that is left over, hence flooding and problems starting the engine.

  3. Bree

    July 18, 2007

    I just bought a Mazda RX 8 2009 model. I want to make sure I take care of the motor and was told I need to treat the car ruff. Meaning I need to step on the gas and get the RPM to 6000 in order to keep the motor happy. I would like to contact other owners of the same model car to make sure I’m doing things right. Hope I can get a buddy :-)

  4. Rotaresearch

    July 18, 2007

    i see that there are some misunderstanding here.
    I wrote this article a few years ago so forgive me if some things don’t sound correct.

    I quote that I wrote “if you start the engine then turn it off before it reaches a good operating temperature, the engine may flood the next time you start it.”
    Also what you could do is rev to 3k for a few seconds before shutting off to help with preventing flooding.

  5. Will

    July 18, 2007

    GRANT BOSS,
    You obviously have not done homework on the rotary or studied it. The rotary engine DOES need to be warmed up before driving over 3k RPM’s. The reason is the engine has a nozzle which sprays oil into the center of the rotor to lubricate it, (not the combustion chanmber) if the oil is thick/cold it will not get the proper amount of oil to lubricate the rotars and greatly reduces the engines life.
    Secondly you didnt read the post properly about the engine flooding.

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