I was about to try new plugs, when I decided to take the old ones over to a friends shop and sand blast them.  (be sure to get all the sand out!)

I put the plugs back in and it fired right up!  When the Renesis plugs get fouled, they are difficult to clean.  Try it…It worked for me. 

 

Bill B

When the RX-8 first hit the street, there were many call backs for re-burns of the computer. And many tow ins for no start. This caused thousands to fall out of love with the rotary. Once the falling cranking speed curve crosses the rate of compression leakage curve, there is no hope at all that it will start.

 

I don't know what strategy they used to overcome this problem. Perhaps no fuel for the first full rotation, so cranking speed is up a bit, or multiple sparks on start up, but finding out what they did might be helpful.

 

Poor starting performance is not a new problem. The old top mounted starters were like 5 HP and spin the thing up right now. I used to drive the race car into the trailer on the starter. The current race car has the top mounted starter. The driver had no idea how things work and would often leave us on the false grid with a no start after a long warm up. Then, any problem that required a shutdown prior to the race start, moved us to last onto the track.

 

The fool proof (you might say) start procedure was 6 full strokes on the throttle. This put a bunch of fuel into the engine, and when the starter was engaged, the throttle was to be just off idle. It started every time.

 

However, the driver would miss the start be sneaking in more throttle while cranking (because as everyone knows, more throttle is better than less throttle) This would get a start and short run and then a stop.

 

The throttle plate is opened past the idle and transition circuit holes, and engine RPM is not high enough for the booster to drop in any fuel. Eventually the idle was raised from the normal 2,000 RPM to 2,200 RPM, and the driver was not allowed to touch the throttle while starting. It worked fine, and I didn't have to dive into the office and operate the throttle pedal by hand to get a start.

 

This was with the side seal end clearance set at zero and not the book value of .002" to .004". And not the two piece corner seals with the rubber plug in the center, but the old solid corner seals. Not the tight fitting two piece seals but one piece carbon seals with .004" end clearance. 

 

The second week after a rebuild, the engine would be so tight, that it would start and drive away if left in first gear, just by touching the starter button. With a 2,200 RPM idle you have to be darn fast at problem solving to prevent a disaster when this happens. In race cars the master switch has to be visible in the corner of the driver or passenger side window.

 

You race on spark plugs that look like any other plug except for the heat range. So if the engine will not be loaded at full throttle for very long, as in the break-in period, very conventional (hot street) plugs work just fine. Plus they cost less than the fancy turbo plugs, and are more difficult to foul. Look how tight the gap is on those stock turbo plugs. Gap any 3/4" reach medium or retracted tip plug to .012" and screw it in.

 

I gap race plugs to .010". They are the coldest heat range on earth, and they do not foul.

 

Those plugs with the 4 thick ground electrodes that look just like airplane plugs are nearly impossible to clean. Once they get a carbon path on them, they are done. It may even have a nice spark in open air, but when a little compression is involved, they do nothing. Just like the ignition is off.

 

If you must clean a plug with blasting, use rice hulls or walnut hulls. Never sand. One grain of sand can ruin a rotary. Plus, sand takes the nice, glass smooth surface off of the porcelain and makes further fouling a sure thing.

 

And one last thought. These engines came with a converter full of oil, or a 42 pound flywheel mounted on them. The flywheel effect is a big help when starting. If there is no mass to help overcome the next rotor going into compression, you need a good crisp powerful hit out of each rotor face to get it going. A lazy sounding whomph now and then is not going to cut it.  The engine is way over square. (The area of the rotor face compared to the stroke) . So, think about a prop if none is installed. A metal prop would be better than a wood prop. I hate to even think about this as there will be some people who do not work well with propellers,

but in any case go slow and be very careful.

 

Lynn E. Hanover 

 

Picture is the race car with the body off (weighs 80 pounds) and the driver Terry Whilock.