I read the threads on getting rid of carbon buildup. So I get a good spray bottle and give it a drink without making it die. It said give it a couple bottles for good measure. I've seen how water can totally clean a boinger cylinder and ( the P word ) when one head gasket lets coolant onto one side. When you pull em both off it's like shiny new vs. soot city !

( If you read my speel, you'd know about 8 years with the dizzy 180 out ! I didn't do it, but dammit I owned it and it's a little embarrassing, I tell you ! ) 3500 miles under those firing conditions has the potential to have made alot of buckyballs.

My question: If I do this procedure, is there any potential for damage or somehow that I can do it wrong and hurt anything ?

 

i did it.. car still running great at almost 192k... i used warm water though, didn't wanna chance anything..

 

i've done it many times. but for danger? i'd say putting anything thats not made for it has a potential danger. but i wouldn't worry. but keep an eye on the temp. when you do it it tends to run hot. i just pretty much pour the water down like i was pouring a glass of beer(without the tilt). then after you do the water, do some mmo also.

 

only thing that might do some damage is if a large chunk of buildup happens to break off and cause problems. i do this at every oil change, along with mmo...can't say its made a difference but id like to think so

 

didn't feel any difference either

 

I used water after recovering from a major flooding issue this spring. Seems to have worked ok, but it may have split my cat. The cat seemed ok before, but toward the end of the water treatment (about two liters worth) I had water running out of a sidelong split in my cat. FYI.

 

I suppose this wouldn't cause much of a problem with a rotary engine since you're not trying to actually compress the water, right?

I've always understood that if you put water in a boinger (mist, not full liquid), it could help it out, but I would think that if you put actually liquid in that it would break something (on a boinger, the rods would get bent and such since you can't compress a liquid.)

What's the deal with this?

 

The dizzy shaft 180° out shouldn't cause a problem because it spins at half eccentric shaft speed.

 

moonchopper is right you don't want to pour it down there, hydrolock is bad. don't be too generous i'm sure you'll be fine.

Ron

 

Steve Kan spoke about this at Sevenstock this year. I actually did this to my 1980 RX-7 yesterday and had no problems. I was skeptical at first and felt kinda of nervous doing it but the car still runs so it seems not to harm it. He said it was hard to hydro a rotary motor. I havent driven the car since it's not registered so i can't tell if there was an improvement.

 

I've had very good success spraying 1/2 a big can of Gumout carb cleaner down the carb chokes with the motor running. Cleans out the carb too!

I did the water spray on the REPU and it did run a little better, but the carb cleaner worked better IMO.

 

I used some carb cleaner spray on my REPU once, which caused it to run better.

 

I suppose it's because the rotor goes in somewhat of a circle instead of straight up and down.

Plus, there aren't any rods to bend in a rotary.

7's own

[edit] Oops, I just realized that you don't put water in it when it's not running. Maybe that's why it works. I would assume it's because it still atomizes the water and allows it to be combusted. (Or something to that effect)

 

bms2004, i dump water down my carb pretty liberally, as long as you keep the revs up around 4k, i think you're aren't gonna run into any problems, of course the rpms drop down a bit once you dump water in, i think mine was right around 3k last time at about 3/4 throttle. The first time i did it, i used a hose to suck water in, i actually think it sucked water down the carb using the vacuum line alot faster than i pour, and i pour it pretty fast.

and by the way, although i've never noticed a difference on my 83, my bros 84 gsl 12a ran a ton smoother after doing the h2o trick, so i know it does help....

 

i did this water trick and afterwards i had water in my oil!!!!!! im not sure what happend, was tring to fix a "stuck seal" but pulled engine apart anyway and a side seal and corner seal were jamed all the way down. the car also kinda smoked a bit before hand at high rpm.

would that have caused the water to get into the oil??

 

I have done this several times... I usually do it once ever 2 or 3 oil changes.... and I don't use a heck of alot of water... just about one cup, and I just quirt it from a gatorade bottle down the carb... The car seems to run abit smoother for awhile after doing this... but I also don't think my car has a serious carbon build up problem either...otherwise you'd think that the h20 treatment wouldhave a greater effect... Myself, I would rather use water than carb cleaner.... carb cleaner just makes me a little nervous, its an agressive chemical, as apposed to water... so I try to stay away from it....but thats just my little superstition, and it probably has no merit to it. Later.

 

I'm not knowledgable enough to argue, but...

At 1/2 the eccentric shaft speed, if the eccentric shaft and rotors turn one revolution, then the dizzy would turn twice and fire off four times total ( two leading and two trailing ). In one complete revolution, both rotors are "positioned" to the firing position 3 times each. It would seem that six (6) firings would be necessary.

Straighten me out, Jeff.

 

Seems like the water treatment is a pretty safe bet. I might give it a try. My 7 runs good, but it saw alot of low rpm/highway driving from the previous owner, so it's probably got some carbon buildup. Can I do this on a GSL-SE though? There's no carb, so I can't just pour it down into the engine.. (Sometimes I miss my old 12a GSL...) What do you guys think?

 

Ever try Amsoil Power Foam? Works fantastic.

 

I don't want to confuse you even more but the rotors turn at 1/3 the speed of the eccentric shaft.

 

^ this is true. and since this is true for every rev the dist fires 2 leading and 2 trailing. this is also the reason why you hook a tach up to a rotary as if its a 4 cyl because 2 signals from a coil per rev.

 

NOW LET ME GET THIS STRAIGHT.

For every one (1) revolution of the concentric shaft,
the rotors turn 1/3 of a revolution ,
for each revolution of the dizzy, one leading and one trailing plug fires
the dizzy shaft turns 2 revolutions per concentric shaft revolution
so the dizzy fires four times per concentric revolution
So for every revolution of concentric shaft, two rotors' faces present for combustion, each requiring a leading and trailing, so 2 each times 2 = 4

OK I got it !!! Thanks

 

close the dizzy turns 180 degrees per eccentric shaft revolution. Thats why its still possible for the dizzy to be 180 degress off. i don't know how to explain it other than that, look at the cap and rotor. yes i have and still confused.

 

Scroll down to the bottom for some pics. you'll notice the arrow on the rotor is not pointing forward, nor is the flat section of the dizzy shaft even though the engine is at TDC. https://www.rx7club.com/forum/showth...9&page=2&pp=15

 

That's not even close. The dizzy only turns 1/2 a revolution for every single revolution of the eccentric shaft. You need to think of the leading and trailing ignitions as completely separate systems even though they share the same distributor.

The only way to learn is to remove the dizzy cap and rotor and take a close look at how it all works. After that you should see how simple it is.