Rotary Engine build Blog

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rotary engine care

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Know the Rotary Engine, facts to help you

Mazda’s Rotary Engine | know the facts




Rotary engine build shop ColoradoIf you are new to the rotary engine world or just need a refresher course? and I know that they need a lot far more care and attention than a standard engine. 

The Mazda Rotary engine when properly built and maintained will last a long time.

Take any shortcuts and it will suffer an early demise. Questions to think about;

  • I was questioning what a list of steps and procedures will support improve the life and functionality of the car. 
  • I know that changing the oil quite often is a have to and maybe adding a small premix to the fuel but what other actions can i comply with?

Rotary engines don’t genuinely take a lot more care, but be aware that there are differences. This is where so many owners get into problems and why rotary engines have such a undesirable rap. 

Let’s cover the basics of taking care of your rotary engine, Turbo and Normally Aspirated:
  • Let the engine warm up a bit just before driving off if you can. Keep RPM’s low until the motor is totally warmed.

  • Do NOT shut off a rotary engine “cold” as this can lead to flooding. Trying to start an Rx8 after it has flooded is not an easy task.

This is since, like all engines, the higher idle fuel flow is greater to keep the motor operating until warmed up a bit. The distinction is that in a rotary the engine design can let excess fuel “pool” at the bottom of the rotor housing, thinning the oil on the walls, and as a result, compression loss. 

You can safely shut off the motor when it drops to low idle (about 800-900 rpm). If you should shut down cold, rev the motor to 3000 rpm and hold for eight – ten seconds. This cuts the fuel flow to normal levels and burns off any excess, stopping flooding.

Never-ever overheat a rotary engine…period. You will warp a rotor housing and then require a new motor. We have one in the shop that ran low on compression and after careful examination / measurements, the rotor housings were not in spec and expanded due to overheating. 

Carbon build up is a larger situation in a rotary, and the harm it can lead to is greater, too. The reason is that this is a rotating combustion chamber, so there is a lot of surface area that can carbon up. Maintain carbon & varnish at bay by providing the engine rev’s when you can. 

Keep it simple:  A red-line a day will keep the mechanic away. Rotary engines love higher rev’s so indulge when it really is safe to do so. Taking long highway drives are yet another very good way to maintain the motor clean. Remember these motors are made for high RPM’s, they like to be wound out.  

Check oil level often. Considering that some oil is injected into the combustion chambers you will have to monitor your oil. Anticipate to add a quart each and every 1500 – 2500 miles. And because oil is injected get fresh oil in there by changing your oil each and every 3000 or so miles. Better yet, add pre-mix.

Rx7 engine buildsExcept for a really handful of particular synthetic oils, keep away from synthetics on your street performance Mazda. Oil injected into the motor wants to burn off as cleanly as achievable in the combustion chambers, and most synthetics are created to NOT burn-off simply. Our full race motors use synthetics, but for street, we recommend what the others say. Use dinosaur oil.

Pre-mixing excellent 2 cycle motor oil into your gas is something a lot of rotary owners do (including me). It provides that tiny added insurance coverage that you’ll have very good lubrication for the rotor seals. You only need 5 ounces per full tank (unless you have a block off plate on the injection pump, then it is 5 ounces per 5 gallons.

If you ever encounter a high temperature of the engine, do not expect it to go away, something is not right, shut it down! You may save many internal components, if you keep driving it, plan on replacing the whole engine. 

If you are curious of the internal status of your engine, get a compression test / inspection. We do offer that service, click on the button below.

The rotary engine is a powerful engine for its size, add a turbocharger (or larger one) and it is even more potent! Taking care of your rotary engine will improve the longevity and fun factor. I like to think of long on-ramps as a place to let that motor sing, wind it out to redline.  A good rotary motor can pull 8500 rpm without any trouble. A well built one, 9500-10300 is more like it. Need help?


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Topics:   rotary engine care

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