Another...How To FIX COMPRESSIONS In Any Rotary Engine with ATF
03-05-2012, 03:18 PM
#52
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No, I haven't done another compression test. It's $150, and even if my compression went up a bit my engine is well below acceptable as you can see in one of the pictures. My car is still difficult to start when warm.
Right now I'm just waiting to order a new engine from either mazparts or Mazda itself. Car still drives fine once it's running.
Right now I'm just waiting to order a new engine from either mazparts or Mazda itself. Car still drives fine once it's running.
03-09-2012, 03:13 PM
#53
Heading out to the garage to try this right now.
Of course I have compression numbers and I will repeat the compression test in 24 hours.
I'm hoping I can get away with one smoke show in my neighborhood
edit ---
My compression battle can be found here
https://www.rx8club.com/group-buy-center-85/tr-01-rotary-engine-compression-tester-official-group-buy-172238/page16/
Of course I have compression numbers and I will repeat the compression test in 24 hours.
I'm hoping I can get away with one smoke show in my neighborhood
edit ---
My compression battle can be found here
https://www.rx8club.com/group-buy-center-85/tr-01-rotary-engine-compression-tester-official-group-buy-172238/page16/
03-10-2012, 04:21 PM
#54
Blah ... put in 500 ml of ATF
Thing smoked like crazy even after a good run.
Once it cleared and the engine was hot I did another compression test.
Zero change.
I guess it's not carbon ... but I'm going to try a seafoam anyways.
Neighbors were cool with the smoke show.
I'm guessing its wear on the apex seals
Thing smoked like crazy even after a good run.
Once it cleared and the engine was hot I did another compression test.
Zero change.
I guess it's not carbon ... but I'm going to try a seafoam anyways.
Neighbors were cool with the smoke show.
I'm guessing its wear on the apex seals
03-10-2012, 04:47 PM
#57
Worth a try, no?
Cost me only 6 dollars and 30 minutes (or about 2 beers lol)
Honestly I didn't expect anything but I've got the time and the compression tester, tools, heated garage and nice weather.
I thought it might be worth documenting all my compression improvement efforts.
Ummm I think I put a link to were I started my discussion.
I've been considering compiling a Cumulative Compression Discussion thread.
Sooo on that note I'll do the Seafoam .. get the exact same compression numbers again ... and put it all in one thread.
Hopefully it will help.
Team, you seem to remember/find/bookmark all sorts of good threads.
I've tried looking for a definitive thread like this, couldn't find anything.
You have something in your magic bag?
Cost me only 6 dollars and 30 minutes (or about 2 beers lol)
Honestly I didn't expect anything but I've got the time and the compression tester, tools, heated garage and nice weather.
I thought it might be worth documenting all my compression improvement efforts.
Ummm I think I put a link to were I started my discussion.
I've been considering compiling a Cumulative Compression Discussion thread.
Sooo on that note I'll do the Seafoam .. get the exact same compression numbers again ... and put it all in one thread.
Hopefully it will help.
Team, you seem to remember/find/bookmark all sorts of good threads.
I've tried looking for a definitive thread like this, couldn't find anything.
You have something in your magic bag?
03-10-2012, 05:34 PM
#60
Really the answer rebuild is an easy conclusion, doing it, affording, is entirely different.
(well for me anyways)
I do have a few feelers out there for estimates.
I am also excited/nervous about trying an engine replacement. I'm not going to try a rebuild that level of expertise I'm not interested in right now.
Oh and when I told the boss, yeah that didn't go so well, she was like "you are buying a motor now?" ..
It was all white noise after that.
Still, I think I've done a good job a documenting my procedures.
Do you think I should start a Cumulative Compression thread.
03-10-2012, 09:38 PM
#62
ur TR-01 works I guess. but my Mazda Compression Tester > yours
A 13B-MSP rebuild is NOT hard at all, at least u don't have to hand grind those side seals (assume you're ok with stock's spec) which is a f-king pain on older Rotary Engines.
Last edited by nycgps; 03-10-2012 at 09:41 PM.
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Kamal El (11-27-2017)
04-04-2012, 11:24 PM
#64
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it's been a month since I did the procedure, and somehow my car now starts on the second attempt when hot... it used to take at least 5 to 10 attempts to start it when hot to the point that running errands or even stop for gas was quite a hassle. I'll keep driving the car like this and see how much longer the engine lasts. I will also do another decarb with the zoom engine cleaner hopefully this sunday.
06-29-2017, 06:17 PM
#65
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I tried it and it worked for me
I tried the ATF trick on a 89 RX7 Turbo 2. Rear rotor that had no compression, and now it has compression and im not even done with the process. Good call.
11-26-2017, 03:08 PM
#67
someone suggested I use half a quart of ATF and drive all week, then change the oil on the weekends. Good Idea?
11-27-2017, 02:25 AM
#68
Smoking turbo yay
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Kamal El (11-27-2017)
11-27-2017, 02:33 AM
#69
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Thread Starter
see TSB.
A cranks, no start condition may be caused either by fuel flooded spark plugs or lower than normal compression
due to apex seals locked into rotor groove from carbon accumulation.
MNAO says add 60cc of 5W30, ATF (IMO) is better.
A cranks, no start condition may be caused either by fuel flooded spark plugs or lower than normal compression
due to apex seals locked into rotor groove from carbon accumulation.
MNAO says add 60cc of 5W30, ATF (IMO) is better.
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Kamal El (04-20-2018)
11-27-2017, 09:55 PM
#70
I was considering a rebuild when I bought it. Just in love with RX-8s.
Mine smokes at start up with light white to lightly tinted blue smoke. I suspect oil control rings because it has to run 20w50 if I don't want to fumigate the road. Oil consumption is high and so I have been casually following the Service Manuals while fixing miscellaneous things.
1 I found a major air leak in the UIM (where the two holes go into the LIM). I suppose the previous mechanic was having a hard time reaching those back bolts, or maybe didn't give one bean( I'm not a mechanic).
2 Changed the engine coolant temperature sensor.
3 Gutted the cat to premix then stopped premixing (I keep the precious guts in two plastic shopping bags, hard to let go...).
4 Fixed a dent in the bumper. The previous owner had an accident that resulted in major bumper and muffler damage
5 welded the muffler pipe connections. The muffler barrels were connected about 40% to the pipes. The rest was cracked open.
6 Cut the barrels open and welded the bafflers(?). It was rattling so loud. I actually have to go back in and redo one of the bafflers.
7 Welded the broken clutch pedal braket
8 Replaced master cylinder
9 Replaced battery terminals with quick connects
10 Programmed Key Fobs
11 Cleaned the ssv
12 Cleaned and tested solenoids and electrical connections on both sides. (tested while solenoids were cold)
13 Modified already modified air hose evap connections (broken elbow connector things). Have a part number?
14 Cleaned air hose and throttle body
15 Changed the plugs that came with the car. Fouled with oil and carbon build up.
16 Took out the new plugs I installed in September and cleaned with carburetor cleaner and a wire brush. The plugs were no longer wet, just white ash and carbon. After cleaning they almost looked new.
17 Today after finally getting a multi meter I tested the SSV and SSV solenoid and found the SSV switch sensor thing (N3H4-18-9B1) to have an ohm rating of 0.6 at its lowest. After previously cleaning and testing the SSV and solenoid without a multi-meter, I can finally say that I know what this P0661 is. The temperature sensor on the SSV (N3H4-18-9B1).
The female side of the connector from the pcm read 12.3v and the solenoid connector read 12.03v. I think that is fine. Right?
Last edited by Kamal El; 11-27-2017 at 10:17 PM.
01-19-2018, 10:42 PM
#71
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Thread Starter
PLEASE take a look at this link, we need your help now, it is self explained.
https://www.rx8club.com/lounge-4/you...3/#post4849721
https://www.rx8club.com/lounge-4/you...3/#post4849721
09-20-2018, 03:59 AM
#72
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IN the 1970's and 80's our Mazda Service Manger would personally fix Bad Compressions in 10A, 12A and 13B Rotaries with Upper Cylinder Lubrication and or mostly ATF (Automatic Transmission Fluid).
After performing a Mazda Compression Test most of the time he would diagnose sticking or stuck IN Rotor Tips APEX SEALS resulting in extreme Blow back and Poor Compressions, some symptoms would be NO Firing of Engines at all.
After the ATF method and a good on road Test Drive / THRASHING many of these engines were given a new life.
I found the same treatment on the web 30 years later.
While the SEAFOAM procedure is good for removing Carbon perhaps you could try the ATF one first and then follow it up with Seafoam.
http://www.mazspeed.com/atf.htm
ATF Treatment By BOBRx-7
Restoring Compression � The ATF Treatment
One of the more common reasons for failure of rotary engines is actually very preventable and in many cases reversible. This entry will cover just how it's done and why it works 95% of the time.
Rotor Seal Design
The rotary engine is among the simplest in overall design. No valves, cams, heads or any of the parts commonly associated with piston engines. This makes them extremely reliable with one major exception. . . the apex seals.
To seal the three tips of each rotor, a groove is machined to accept a long thin cast iron (in stock engines) insert. This is the apex seal. A spring, located behind the seal, applies the force needed to hold the seal in contact with the rotor housing wall as it passes around the inside housing wall. As the apex seals pass the narrow points in the housing, they are compressed against the springs and then move back outward in the wider parts of the housing. A corner seal at each end of the apex seal is also spring loaded to prevent combustion gasses from leaking around the ends of the rotor tip. Additional seals on the sides of the rotor complete the set to form a relatively leak-free chamber.
Over time, carbon, ash and oil sludge deposits will accumulate in the machined groove in the rotor tip. If allowed to remain, the apex seals will eventually begin to bind in the grooves and will not move outward completely during the combustion cycle or intake cycle. This allows gasses to escape into the next chamber, reducing compression. In the extreme, the apex seals will stick in the compressed position to the extent that virtually all compression is lost. At this point, the engine will likely refuse to run at all.
Dirty oil and general lack of maintenance is the most common cause of compression loss. The oil injection system on the rotary is designed to feed oil in to the chamber to keep both the housing walls and the apex and corner seals lubricated and clean. Dirty oil will simply throw grit, sludge and other combustion debris back into the chamber. Result, thousands of perfectly good 12A and 13B engines, or complete cars, rotting in the junk yard, for no good reason!!!!
Preventive Care
The obvious solution here is consistent oil changes. Never more than 3000 miles between changes and good (spelled Castrol GTX 20W50) oil with a new filter. By the way, the puny little factory filter is COMPLETELY inadequate. A remote filter setup that will allow the use of a 1 qt. filter is much better. At the very least, use a K&N or WIX filter in the stock location. These will filter particles down to 10 microns. A better oil cooler on those 83-85 12A engines is also an excellent idea.
The Fix
So what if your engine is already suffering from the dreaded sticking/seized apex seals, you ask?? Never fear. An old mechanics trick used to free up sticking valves and lifters works WONDERS on your rotary. The procedure works a little differently for carbureted engines that the EGI models, but accomplishes the same results.
1.
Disable the ignition primary circuit by disconnecting the igniters or the negative lead on each ignition coil.
2.
Remove the air cleaner lid on carbureted engines, or pull the Leading (lower) plugs on 13B EGI engines.
3.
For carbureted engines, pour 2 oz. (60 mil) Automatic Transmission Fluid (ATF) (the cheap stuff is fine) down each primary bore (the small ones) of the carb, while an assistant cranks the engine for 5 seconds or so. On EGI engines, use an oil squirt can and pump two or three shots into leach leading spark plug hole. Have an assistant lightly bump the starter two or three times, squirt in more oil, bump the starter, squirt, bump, squirt, bump. . . you get the idea. You want to get ATF in all chambers and thoroughly distributed. Reinstall the spark plugs on EGI engines.
4.
Allow the engine to sit in the ATF stew for AT LEAST 24 hours. Don't be tempted to rush the process. This takes time. The detergents in the fluid, used to keep the small polished valves in an auto trans valve body free, will soften the carbon and sludge deposits.
5.
PLEASE. . . Make sure the car is outside for this step. You'll see why. Reconnect the ignition system, hold the throttle open way on carbureted engine and start it up. Allow to idle. The neighbors will now think that Mt. St. Helens has erupted in you driveway or a massive brush fire has broken out. It will take about 5 minutes for the smoke to clear completely, since some of the ATF has worked it's way into the exhaust pipe and must be burned off.
6.
Install a new set of plugs. The ATF will foul the old ones and may cause hi-speed misfire. Take the car out on the free-way and THRASH IT for a few miles to completely clear the chambers. 6 to 10 redline runs will do it.
At this point, the apex and corner seals can move freely again. In extreme cases, you may want to repeat the treatment after a week or so of driving. If so, hang on to the old plugs to use again for the second treatment.
If you were to perform a before and after compression test, you could potentially see an increase of 20 psi or more and will feel a whole lot of power that wasn't there before. I have revived engines that would not start and know of a couple ITA drivers running junk yard engines brought back to life this way.
IT'S CHEAP. . . IT WORKS. . . And you can end up with a nearly new engine for $2. You've gotta love it!!
HAPPY ROTORING!!
Bobrx7
After performing a Mazda Compression Test most of the time he would diagnose sticking or stuck IN Rotor Tips APEX SEALS resulting in extreme Blow back and Poor Compressions, some symptoms would be NO Firing of Engines at all.
After the ATF method and a good on road Test Drive / THRASHING many of these engines were given a new life.
I found the same treatment on the web 30 years later.
While the SEAFOAM procedure is good for removing Carbon perhaps you could try the ATF one first and then follow it up with Seafoam.
http://www.mazspeed.com/atf.htm
ATF Treatment By BOBRx-7
Restoring Compression � The ATF Treatment
One of the more common reasons for failure of rotary engines is actually very preventable and in many cases reversible. This entry will cover just how it's done and why it works 95% of the time.
Rotor Seal Design
The rotary engine is among the simplest in overall design. No valves, cams, heads or any of the parts commonly associated with piston engines. This makes them extremely reliable with one major exception. . . the apex seals.
To seal the three tips of each rotor, a groove is machined to accept a long thin cast iron (in stock engines) insert. This is the apex seal. A spring, located behind the seal, applies the force needed to hold the seal in contact with the rotor housing wall as it passes around the inside housing wall. As the apex seals pass the narrow points in the housing, they are compressed against the springs and then move back outward in the wider parts of the housing. A corner seal at each end of the apex seal is also spring loaded to prevent combustion gasses from leaking around the ends of the rotor tip. Additional seals on the sides of the rotor complete the set to form a relatively leak-free chamber.
Over time, carbon, ash and oil sludge deposits will accumulate in the machined groove in the rotor tip. If allowed to remain, the apex seals will eventually begin to bind in the grooves and will not move outward completely during the combustion cycle or intake cycle. This allows gasses to escape into the next chamber, reducing compression. In the extreme, the apex seals will stick in the compressed position to the extent that virtually all compression is lost. At this point, the engine will likely refuse to run at all.
Dirty oil and general lack of maintenance is the most common cause of compression loss. The oil injection system on the rotary is designed to feed oil in to the chamber to keep both the housing walls and the apex and corner seals lubricated and clean. Dirty oil will simply throw grit, sludge and other combustion debris back into the chamber. Result, thousands of perfectly good 12A and 13B engines, or complete cars, rotting in the junk yard, for no good reason!!!!
Preventive Care
The obvious solution here is consistent oil changes. Never more than 3000 miles between changes and good (spelled Castrol GTX 20W50) oil with a new filter. By the way, the puny little factory filter is COMPLETELY inadequate. A remote filter setup that will allow the use of a 1 qt. filter is much better. At the very least, use a K&N or WIX filter in the stock location. These will filter particles down to 10 microns. A better oil cooler on those 83-85 12A engines is also an excellent idea.
The Fix
So what if your engine is already suffering from the dreaded sticking/seized apex seals, you ask?? Never fear. An old mechanics trick used to free up sticking valves and lifters works WONDERS on your rotary. The procedure works a little differently for carbureted engines that the EGI models, but accomplishes the same results.
1.
Disable the ignition primary circuit by disconnecting the igniters or the negative lead on each ignition coil.
2.
Remove the air cleaner lid on carbureted engines, or pull the Leading (lower) plugs on 13B EGI engines.
3.
For carbureted engines, pour 2 oz. (60 mil) Automatic Transmission Fluid (ATF) (the cheap stuff is fine) down each primary bore (the small ones) of the carb, while an assistant cranks the engine for 5 seconds or so. On EGI engines, use an oil squirt can and pump two or three shots into leach leading spark plug hole. Have an assistant lightly bump the starter two or three times, squirt in more oil, bump the starter, squirt, bump, squirt, bump. . . you get the idea. You want to get ATF in all chambers and thoroughly distributed. Reinstall the spark plugs on EGI engines.
4.
Allow the engine to sit in the ATF stew for AT LEAST 24 hours. Don't be tempted to rush the process. This takes time. The detergents in the fluid, used to keep the small polished valves in an auto trans valve body free, will soften the carbon and sludge deposits.
5.
PLEASE. . . Make sure the car is outside for this step. You'll see why. Reconnect the ignition system, hold the throttle open way on carbureted engine and start it up. Allow to idle. The neighbors will now think that Mt. St. Helens has erupted in you driveway or a massive brush fire has broken out. It will take about 5 minutes for the smoke to clear completely, since some of the ATF has worked it's way into the exhaust pipe and must be burned off.
6.
Install a new set of plugs. The ATF will foul the old ones and may cause hi-speed misfire. Take the car out on the free-way and THRASH IT for a few miles to completely clear the chambers. 6 to 10 redline runs will do it.
At this point, the apex and corner seals can move freely again. In extreme cases, you may want to repeat the treatment after a week or so of driving. If so, hang on to the old plugs to use again for the second treatment.
If you were to perform a before and after compression test, you could potentially see an increase of 20 psi or more and will feel a whole lot of power that wasn't there before. I have revived engines that would not start and know of a couple ITA drivers running junk yard engines brought back to life this way.
IT'S CHEAP. . . IT WORKS. . . And you can end up with a nearly new engine for $2. You've gotta love it!!
HAPPY ROTORING!!
Bobrx7
09-20-2018, 01:39 PM
#73
Metatron
iTrader: (1)
"The detergents in the fluid, used to keep the small polished valves in an auto trans valve body free, will soften the carbon and sludge deposits."
I 've said it many times before, but apparently it bears repeating -
There are NO detergents in ATF.
Actually just the opposite, the additive package ensures that any crud or particles are NOT suspended and circulated, but dropped in the pan. So the exact opposite of a detergent.
A modern diesel engine oil or the Seafoam mentioned, may be better for decrusting/softening, even WD-40 or Marvel oil.
ATF is basically a low viscosity hydraulic fluid, loaded with antifoam, rust preventatives, friction and viscosity modifiers, and anti-oxidants
....and none of these additives are specified as to how well they burn or the deposits left, so don't even think about it as a premix.
I 've said it many times before, but apparently it bears repeating -
There are NO detergents in ATF.
Actually just the opposite, the additive package ensures that any crud or particles are NOT suspended and circulated, but dropped in the pan. So the exact opposite of a detergent.
A modern diesel engine oil or the Seafoam mentioned, may be better for decrusting/softening, even WD-40 or Marvel oil.
ATF is basically a low viscosity hydraulic fluid, loaded with antifoam, rust preventatives, friction and viscosity modifiers, and anti-oxidants
....and none of these additives are specified as to how well they burn or the deposits left, so don't even think about it as a premix.
09-20-2018, 05:44 PM
#74
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Sounds like ATF has flocculants.
03-30-2019, 05:04 AM
#75
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Thanks for this trick!
IN the 1970's and 80's our Mazda Service Manger would personally fix Bad Compressions in 10A, 12A and 13B Rotaries with Upper Cylinder Lubrication and or mostly ATF (Automatic Transmission Fluid).
After performing a Mazda Compression Test most of the time he would diagnose sticking or stuck IN Rotor Tips APEX SEALS resulting in extreme Blow back and Poor Compressions, some symptoms would be NO Firing of Engines at all.
After the ATF method and a good on road Test Drive / THRASHING many of these engines were given a new life.
I found the same treatment on the web 30 years later.
While the SEAFOAM procedure is good for removing Carbon perhaps you could try the ATF one first and then follow it up with Seafoam.
http://www.mazspeed.com/atf.htm
ATF Treatment By BOBRx-7
Restoring Compression � The ATF Treatment
One of the more common reasons for failure of rotary engines is actually very preventable and in many cases reversible. This entry will cover just how it's done and why it works 95% of the time.
Rotor Seal Design
The rotary engine is among the simplest in overall design. No valves, cams, heads or any of the parts commonly associated with piston engines. This makes them extremely reliable with one major exception. . . the apex seals.
To seal the three tips of each rotor, a groove is machined to accept a long thin cast iron (in stock engines) insert. This is the apex seal. A spring, located behind the seal, applies the force needed to hold the seal in contact with the rotor housing wall as it passes around the inside housing wall. As the apex seals pass the narrow points in the housing, they are compressed against the springs and then move back outward in the wider parts of the housing. A corner seal at each end of the apex seal is also spring loaded to prevent combustion gasses from leaking around the ends of the rotor tip. Additional seals on the sides of the rotor complete the set to form a relatively leak-free chamber.
Over time, carbon, ash and oil sludge deposits will accumulate in the machined groove in the rotor tip. If allowed to remain, the apex seals will eventually begin to bind in the grooves and will not move outward completely during the combustion cycle or intake cycle. This allows gasses to escape into the next chamber, reducing compression. In the extreme, the apex seals will stick in the compressed position to the extent that virtually all compression is lost. At this point, the engine will likely refuse to run at all.
Dirty oil and general lack of maintenance is the most common cause of compression loss. The oil injection system on the rotary is designed to feed oil in to the chamber to keep both the housing walls and the apex and corner seals lubricated and clean. Dirty oil will simply throw grit, sludge and other combustion debris back into the chamber. Result, thousands of perfectly good 12A and 13B engines, or complete cars, rotting in the junk yard, for no good reason!!!!
Preventive Care
The obvious solution here is consistent oil changes. Never more than 3000 miles between changes and good (spelled Castrol GTX 20W50) oil with a new filter. By the way, the puny little factory filter is COMPLETELY inadequate. A remote filter setup that will allow the use of a 1 qt. filter is much better. At the very least, use a K&N or WIX filter in the stock location. These will filter particles down to 10 microns. A better oil cooler on those 83-85 12A engines is also an excellent idea.
The Fix
So what if your engine is already suffering from the dreaded sticking/seized apex seals, you ask?? Never fear. An old mechanics trick used to free up sticking valves and lifters works WONDERS on your rotary. The procedure works a little differently for carbureted engines that the EGI models, but accomplishes the same results.
1.
Disable the ignition primary circuit by disconnecting the igniters or the negative lead on each ignition coil.
2.
Remove the air cleaner lid on carbureted engines, or pull the Leading (lower) plugs on 13B EGI engines.
3.
For carbureted engines, pour 2 oz. (60 mil) Automatic Transmission Fluid (ATF) (the cheap stuff is fine) down each primary bore (the small ones) of the carb, while an assistant cranks the engine for 5 seconds or so. On EGI engines, use an oil squirt can and pump two or three shots into leach leading spark plug hole. Have an assistant lightly bump the starter two or three times, squirt in more oil, bump the starter, squirt, bump, squirt, bump. . . you get the idea. You want to get ATF in all chambers and thoroughly distributed. Reinstall the spark plugs on EGI engines.
4.
Allow the engine to sit in the ATF stew for AT LEAST 24 hours. Don't be tempted to rush the process. This takes time. The detergents in the fluid, used to keep the small polished valves in an auto trans valve body free, will soften the carbon and sludge deposits.
5.
PLEASE. . . Make sure the car is outside for this step. You'll see why. Reconnect the ignition system, hold the throttle open way on carbureted engine and start it up. Allow to idle. The neighbors will now think that Mt. St. Helens has erupted in you driveway or a massive brush fire has broken out. It will take about 5 minutes for the smoke to clear completely, since some of the ATF has worked it's way into the exhaust pipe and must be burned off.
6.
Install a new set of plugs. The ATF will foul the old ones and may cause hi-speed misfire. Take the car out on the free-way and THRASH IT for a few miles to completely clear the chambers. 6 to 10 redline runs will do it.
At this point, the apex and corner seals can move freely again. In extreme cases, you may want to repeat the treatment after a week or so of driving. If so, hang on to the old plugs to use again for the second treatment.
If you were to perform a before and after compression test, you could potentially see an increase of 20 psi or more and will feel a whole lot of power that wasn't there before. I have revived engines that would not start and know of a couple ITA drivers running junk yard engines brought back to life this way.
IT'S CHEAP. . . IT WORKS. . . And you can end up with a nearly new engine for $2. You've gotta love it!!
HAPPY ROTORING!!
Bobrx7
After performing a Mazda Compression Test most of the time he would diagnose sticking or stuck IN Rotor Tips APEX SEALS resulting in extreme Blow back and Poor Compressions, some symptoms would be NO Firing of Engines at all.
After the ATF method and a good on road Test Drive / THRASHING many of these engines were given a new life.
I found the same treatment on the web 30 years later.
While the SEAFOAM procedure is good for removing Carbon perhaps you could try the ATF one first and then follow it up with Seafoam.
http://www.mazspeed.com/atf.htm
ATF Treatment By BOBRx-7
Restoring Compression � The ATF Treatment
One of the more common reasons for failure of rotary engines is actually very preventable and in many cases reversible. This entry will cover just how it's done and why it works 95% of the time.
Rotor Seal Design
The rotary engine is among the simplest in overall design. No valves, cams, heads or any of the parts commonly associated with piston engines. This makes them extremely reliable with one major exception. . . the apex seals.
To seal the three tips of each rotor, a groove is machined to accept a long thin cast iron (in stock engines) insert. This is the apex seal. A spring, located behind the seal, applies the force needed to hold the seal in contact with the rotor housing wall as it passes around the inside housing wall. As the apex seals pass the narrow points in the housing, they are compressed against the springs and then move back outward in the wider parts of the housing. A corner seal at each end of the apex seal is also spring loaded to prevent combustion gasses from leaking around the ends of the rotor tip. Additional seals on the sides of the rotor complete the set to form a relatively leak-free chamber.
Over time, carbon, ash and oil sludge deposits will accumulate in the machined groove in the rotor tip. If allowed to remain, the apex seals will eventually begin to bind in the grooves and will not move outward completely during the combustion cycle or intake cycle. This allows gasses to escape into the next chamber, reducing compression. In the extreme, the apex seals will stick in the compressed position to the extent that virtually all compression is lost. At this point, the engine will likely refuse to run at all.
Dirty oil and general lack of maintenance is the most common cause of compression loss. The oil injection system on the rotary is designed to feed oil in to the chamber to keep both the housing walls and the apex and corner seals lubricated and clean. Dirty oil will simply throw grit, sludge and other combustion debris back into the chamber. Result, thousands of perfectly good 12A and 13B engines, or complete cars, rotting in the junk yard, for no good reason!!!!
Preventive Care
The obvious solution here is consistent oil changes. Never more than 3000 miles between changes and good (spelled Castrol GTX 20W50) oil with a new filter. By the way, the puny little factory filter is COMPLETELY inadequate. A remote filter setup that will allow the use of a 1 qt. filter is much better. At the very least, use a K&N or WIX filter in the stock location. These will filter particles down to 10 microns. A better oil cooler on those 83-85 12A engines is also an excellent idea.
The Fix
So what if your engine is already suffering from the dreaded sticking/seized apex seals, you ask?? Never fear. An old mechanics trick used to free up sticking valves and lifters works WONDERS on your rotary. The procedure works a little differently for carbureted engines that the EGI models, but accomplishes the same results.
1.
Disable the ignition primary circuit by disconnecting the igniters or the negative lead on each ignition coil.
2.
Remove the air cleaner lid on carbureted engines, or pull the Leading (lower) plugs on 13B EGI engines.
3.
For carbureted engines, pour 2 oz. (60 mil) Automatic Transmission Fluid (ATF) (the cheap stuff is fine) down each primary bore (the small ones) of the carb, while an assistant cranks the engine for 5 seconds or so. On EGI engines, use an oil squirt can and pump two or three shots into leach leading spark plug hole. Have an assistant lightly bump the starter two or three times, squirt in more oil, bump the starter, squirt, bump, squirt, bump. . . you get the idea. You want to get ATF in all chambers and thoroughly distributed. Reinstall the spark plugs on EGI engines.
4.
Allow the engine to sit in the ATF stew for AT LEAST 24 hours. Don't be tempted to rush the process. This takes time. The detergents in the fluid, used to keep the small polished valves in an auto trans valve body free, will soften the carbon and sludge deposits.
5.
PLEASE. . . Make sure the car is outside for this step. You'll see why. Reconnect the ignition system, hold the throttle open way on carbureted engine and start it up. Allow to idle. The neighbors will now think that Mt. St. Helens has erupted in you driveway or a massive brush fire has broken out. It will take about 5 minutes for the smoke to clear completely, since some of the ATF has worked it's way into the exhaust pipe and must be burned off.
6.
Install a new set of plugs. The ATF will foul the old ones and may cause hi-speed misfire. Take the car out on the free-way and THRASH IT for a few miles to completely clear the chambers. 6 to 10 redline runs will do it.
At this point, the apex and corner seals can move freely again. In extreme cases, you may want to repeat the treatment after a week or so of driving. If so, hang on to the old plugs to use again for the second treatment.
If you were to perform a before and after compression test, you could potentially see an increase of 20 psi or more and will feel a whole lot of power that wasn't there before. I have revived engines that would not start and know of a couple ITA drivers running junk yard engines brought back to life this way.
IT'S CHEAP. . . IT WORKS. . . And you can end up with a nearly new engine for $2. You've gotta love it!!
HAPPY ROTORING!!
Bobrx7
thanks guys! I’m trying this trick tomorrow!
Very usefull thanks guys for sharing this information since I couldn’t find anything anywhere else!
I have an RX7 s4 na and one of the rotors doesn’t have any compression, the seals are stuck in there place but because of carbon buildup.. they are not coming properly out!
Wish me good luck and thanks again!
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