peejay

I found a bottle of ATF (several, actually) and used half of it to soak the '80 12A in the garage. (Now it can turn! )

I put the other half into a pot. Then I put a carboned-up, nasty rotor from the dead engine into it, with one face down. The ATF level is just deep enough to come up to the apex seal grooves. I picked the rotor back up and noted the ATF was still clean.

3 hours later I went back and picked the rotor up carefully and looked at the face. Couldn't tell if any carbon was gone or not, but I had evidence that it was. The ATF had black crud in it now. It was still red, but it had fine black particles swirling around in it. I'll check on it at around 9pm if I'm still home to see what it looks like after 6 hours.

Very Interesting....

(before you ask for pics - my digital camera is down, and any other way of putting pics up will not have any good detail)

riffraff

guess we know that the stuff really works then.

repuguru

Do you think the engine has a problem expelling all the crud after the soak?

MIKE-P-28

iTrader: (1)

GOOD LUCK... I let 2 rotors sit in ATF for over a month, and it made HARDLY ANY DIFFERENCE... Only thing that would clean them was paint thinner or/and Kerosene

I personally dont think ATF does **** to carbon deposits, its just me tho. Only thing I ever seen it good for was a carbon locked motor to give it enough compression to start ...

85RX7GS

iTrader: (1)

You're probably right Mike. Even if you can get your car to run after the ATF treatment (mine didn't), there are still going to be loads of carbon clumped up in a pocket somewhere. As for paint thinner, that stuff will disolve carbon deposits (I dumped some on a plastic sprinkler once and it melted into a blob). Anyway, to make a long story short, I think that ATF should only be used on carbon locked engines.

MIKE-P-28

iTrader: (1)

I wasnt saying pour paint thinner inside a motor. I know thats not what you thought. BUT i just wanted to make sure everyone understands... Paint thinner and Kerosene make good parts cleaners... That and a good scrub brush and a lot of work...

peejay

Well, okay it's roughly... uh... 21 hours later

The bottom of the pot is a layer of black carbon silt. The rotor now has shiney spots on the machined part of the face. The unmachined "bathtub" is still black with carbon.

I have a feeling that the ATF will only work so much - the detergents dissolve the carbon and then fall out of suspension - eventually the detergents will be depleted. (The particles are too small to cause any problems, and they'd blow right out after you start up. Remember, pieces of carbon are getting blown off all the time just in the course of driving) Later today I'll try scrubbing it. I've tried kerosene and a ton of elbow grease before, it doesn't work too good

We had this stuff at the one shop, I forgot what it was called, but we'd take pistons, valves, anything heavily crusted up, dunk it in the stuff overnight, the next day the parts were gleaming with not a speck of carbon in sight.

MIKE-P-28

iTrader: (1)

Yeah I ve heard of that stuff, man whats that stuff called?

peejay

I think it's the same stuff as carb dunk, but that's not what it was called.

One bad thing about it - it attacks plastic and rubber, so it's not a good idea to put it in an engine, or dip all-up rotors in it if you want to re-use the oil seals or corner seal rubber pieces.

Directfreak

iTrader: (2)

When I was younger, I worked at a Marine Shop where people would bring outboard motors, V8's and such that were completely siezed and disgusting from either sinking in Salt Water or just bad maintenance.

On of the "secrets" we used to do was have a 55 Gallon drum of Diesel fuel.

We would take the whole engine minus accesories, and dunk it for a day or two in the diesel fuel.

Afterwards, it wouldn't be siezed any more, a little scrubbing, and they looked VERY clean. Then we'd put the intake and exhaust back on and start-em up. If it didn't work, then it needed a rebuild anyway.

I still do this when I work on the occasional Jet-Ski (2-stroke) engine when it appears past repair, plus still use it to clean parts.

Diesel fuel will burn like gas, stink and smoke, but it will burn out of a running engine. I've wondered if anybody has ever tried it with the relatively small rotaries to see if would work on siezed engines.

Any ideas?

peejay

I've heard of that before - several references to it on Dave Williams' site.

I took the rotor out and scrubbed it a little with a worn-out fingernail scrubber brush. The brush is totally worn out, but still it removed most of the carbon like pudding skin.

Northern 7

iTrader: (3)

peejay - so wouldn't the fact that the ATF loosened up the carbon be a possitive? I mean if it's softening up as you describe, wouldn't a lot of it fall away and get blown through? I do the ATF thing every Fall and I'm hoping I haven't been waisting my time. I've never really seen much of an improvement in performance from doing this and I never really expected to - My thinking was more or less just preventitive medicine.

peejay

I was just trying to see how well it dissolves carbon - and it does. Rather well. Not as well as hardcore carbon-dissolving solvents, but then again those are poor lubricants and attack rubber seals.

nimrodTT

deisel on the rubber seals - what happens?

Northern 7

iTrader: (3)

peejay - that's what I was hoping you would say. I've always wanted to see (with my own eyes) how the ATF reacted with carbon build-up - thanks for the reply

MIKE-P-28

iTrader: (1)

Wouldnt be any worse than gasoline right?

Directfreak

iTrader: (2)

Your guess is a good as mine. I've never done it to a Rotary, but with all the natural lubricants in Diesel (a La 2-stroke) I would *think* it could do nothing bad.

peejay

http://www.angelfire.com/ar/dw42/tools/shop.htm Pay close attention to what's in the barrels.

http://www.angelfire.com/ar/dw42/tools/machine.htm Pay close attention to the engine honing tank.

http://www.angelfire.com/ar/dw42/ An excellent site overall.

Directfreak

iTrader: (2)

What's in the barrels?