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Mazda rotary engines are designed with oil injection to lubricate the seals - they are designed to consume oil. Rotaries, properly cared for, are a reliable en

by brc 11y ago

Mazda rotary engines are designed with oil injection to lubricate the seals - they are designed to consume oil. Rotaries, properly cared for, are a reliable engine with fantastic power delivery and small size. It's a shame they are plagued with high fuel consumption which limits their usefulness in anything but sports and racing applications. If you read the article this is not a conventional wankel rotary - the rotor design looks like a wankel housing, so it's flipped around.

watmough 11y ago
Reputedly, if you own an RX-7 or RX-8, you should spin the engine up to 9k revs at least once every trip... lest carbon deposits build up and wreak havoc. I can't imagine a technology like this is that well suited to constant and relatively low power delivery.
- busterarm 11y ago
  Not entirely accurate. The 5th and 6th ports don't open up until 3800 and ideally you want to slightly redline it for a few seconds, but you definitely want to at least open up those ports. You can also get away with not doing it for a while, but you shouldn't. on a pre-89 that (factory) redline is at 7k, 8k on 89-. RX8s you have to hit 9k. This does make it hard not to speed in an RX7, especially if you've done a little bit of work to it - not so much in the RX8.
- brc 11y ago
  Rotary engines make good constant speed engines because the intake and exhaust ports can be tuned for that constant running. They're also ideal for alternative fuels like natural gas because the combustion chamber is in a different location to the intake/compression, which makes it easier to limit uncontrolled ignition (detonation). And the oil injection makes them suitable for adding specific lubricants to the intake charge. On the topic of giving engines a good dose of WOT and revs, all modern direct injection cars need this as the loss of port injection means that the intake runners and valves are no longer given a constrant stream of fuel to clean them. As some exhaust gases enter the intake runners when valves overlap, over time this leads to massive carbon buildup in the intake side. Google some pictures of Audi engines with carbon deposits - makes your eyes water. So if you have a modern direct-injection petrol injection make sure you give it a good 'italian tune up' on frequent occasions as well.

by brc 11y ago

watmough 11y ago

Reputedly, if you own an RX-7 or RX-8, you should spin the engine up to 9k revs at least once every trip... lest carbon deposits build up and wreak havoc. I can't imagine a technology like this is that well suited to constant and relatively low power delivery.

busterarm 11y ago
Not entirely accurate. The 5th and 6th ports don't open up until 3800 and ideally you want to slightly redline it for a few seconds, but you definitely want to at least open up those ports. You can also get away with not doing it for a while, but you shouldn't. on a pre-89 that (factory) redline is at 7k, 8k on 89-. RX8s you have to hit 9k. This does make it hard not to speed in an RX7, especially if you've done a little bit of work to it - not so much in the RX8.
brc 11y ago
Rotary engines make good constant speed engines because the intake and exhaust ports can be tuned for that constant running. They're also ideal for alternative fuels like natural gas because the combustion chamber is in a different location to the intake/compression, which makes it easier to limit uncontrolled ignition (detonation). And the oil injection makes them suitable for adding specific lubricants to the intake charge. On the topic of giving engines a good dose of WOT and revs, all modern direct injection cars need this as the loss of port injection means that the intake runners and valves are no longer given a constrant stream of fuel to clean them. As some exhaust gases enter the intake runners when valves overlap, over time this leads to massive carbon buildup in the intake side. Google some pictures of Audi engines with carbon deposits - makes your eyes water. So if you have a modern direct-injection petrol injection make sure you give it a good 'italian tune up' on frequent occasions as well.