High water and an RX-8 = $$$

rotarygod · 11-17-2003, 06:54 PM

It not mine since I don't have one yet. Houston has been pummeled by weather all day today. At about 5:30 I saw a tow truck pulling a Silver RX-8 down Cypresswood drive at Stuebner Airline. It was an auto judging by the smaller rims and fact that the truck had the back wheels off the ground while the fronts were rolling. I hope it isn't anyone here's car.

Please people, if you have to ask if the water is too high, IT IS!!! Better be safe than sorry.

Now here's a little info on the rotary and water ingestion just to help put you all at ease should it happen to you. A few years ago a friend and I picked up a 3rd gen RX-7 that had driven into flood waters. The owner was upset and was certain the engine was dead. We pulled off the intercooler and poured water out of it. We pulled out the spark plugs and water drained from the engine. The engine was not locked up though when we tried to turn it so we got to thinking. We pulled the car down the street in gear to help get all the water out of the engine and related parts. New plugs were installed after a small amount of atf was poured into the engine through the spark plug holes. We again pulled the car down the street in gear this time trying to start it. After about 2 miles it sputtered a little then came to life! The car was running on its own. After a complete fluid change in the car we continued to drive the car over the next 2 days. After the end of the 2nd day full power was restored. Water had completely flooded the engine but it did not die. Heres why:

On a piston engine the piston rings edges are rectangular. When water gets into the combusion chamber and tries to compress all of the force of the water can not push the rings back into their seats and the seals break allowing water to enter the crankcase. Remember that water can not be compressed. Don't confuse this with water pressure. On a rotary the apex seal tips are rounded since their suface rotates in relation to the housings as the rotor spins. When water gets into the rotary combustion chamber a small amount gets under the apex seal edges. When the rotor tries to compress the water it exerts alot of pressure. Since some of this water is under the rounded edges of the apex seals, the water pressure forces the apex seal down into it's groove. This allows the water and pressure to run into the next chamber. The water obviously kills the combustion process shutting the engine off. Each chamber will fill due to the same forces on the apex seals and their allowance of fluids to pass them into the next. This will happen up until the water leaves the engine out the exhaust port. Even if the piston rings of a piston engine were rounded, the water would still contaminate the crank case oil supply where it didn't on the rotary. It is a good idea never the less to change all of the cars fluids. This phenomenon while unique to the rotary does not guarantee that the engine will not be damaged in some way. It is still possible that a seal breaks but not nearly as likely as a piston engine. Hopefully this info gives you a little comfort about your rotary engine. Just because it is full of water doesn't mean that it is dead, just very very hard to start.

This ad is not displayed to registered and logged-in members.
Register your free account today and become a member on RX8Club.com!

panda · 11-17-2003, 11:46 PM

thats for the info, i got back from school today and put mine into the garage, and left it there...no way i was driving it in that.....took the parents SUV! haha

thanks for the info man
andrew

allstate · 11-18-2003, 10:33 AM

Quote:

Originally posted by rotarygod
It not mine since I don't have one yet. Houston has been pummeled by weather all day today. At about 5:30 I saw a tow truck pulling a Silver RX-8 down Cypresswood drive at Stuebner Airline. It was an auto judging by the smaller rims and fact that the truck had the back wheels off the ground while the fronts were rolling. I hope it isn't anyone here's car.

I used to work in that area. I was a flight instructor at David Wayne Hooks airport. I was there when tropical storm Allison hit and everything was flooded. Hope everyone made it ok this time.

rotarygod · 11-18-2003, 11:37 AM

I didn't have any problems with water other than stuff that I left outside getting wet. I was out of town when Allison hit. I was on a beach in south Thailand when I heard about it on CNN. Poor me :D

HIX8 · 11-25-2003, 08:28 PM

Quote:

rotarygod:
It not mine since I don't have one yet. Houston has been pummeled by weather all day today. At about 5:30 I saw a tow truck pulling a Silver RX-8 down Cypresswood drive at Stuebner Airline. It was an auto judging by the smaller rims and fact that the truck had the back wheels off the ground while the fronts were rolling. I hope it isn't anyone here's car.

Please people, if you have to ask if the water is too high, IT IS!!! Better be safe than sorry.
<snip>

One of the reasons why the RX-8 is so succeptible to high water is that sports car designers like to put the air scoop down low where the air pressure is higher.

If you take a look up front at exactly how low the intake is, you can see that it doesn't take much standing water to DROWN your renesis.

If someone is ever in a situation where an emergency is forcing them to have to drive through a flooded street in their RX-8, I guess a solution might be to block the low air intake and open up the air system somewhere higher (filter?).

Of course, it's a stretch to come up with a scenario that drastic. And if water got into the cabin you'd still be looking at $$$, as the subject line warns.