Apex seal stuck in rotor? 12a
12-15-15, 03:52 PM
#1
Full Member
Thread Starter
Apex seal stuck in rotor? 12a
Hello all! i got a quick question for anyone who can help me..do you think my apex seal could be stuck in the rotor from carbon build up? this is what happened.
so i started my 82 12a rx7 yesterday let it idle for a while until it was warm enough and i was messing with it tweaking stuff and i when i floored it and it hit about 7k rpm and then all of a sudden ran like crap...now if i take a spark plug out of rotor 1 i hear 2 loud puffs and a weak one. ive been fouling plugs lately before i fixed my float issue so i know there was alot of carbon build up in there so im thinking thats what it is and i already tried to decarbon it by putting water thru the carb and letting it steam clean it with no luck. any ideas?
so i started my 82 12a rx7 yesterday let it idle for a while until it was warm enough and i was messing with it tweaking stuff and i when i floored it and it hit about 7k rpm and then all of a sudden ran like crap...now if i take a spark plug out of rotor 1 i hear 2 loud puffs and a weak one. ive been fouling plugs lately before i fixed my float issue so i know there was alot of carbon build up in there so im thinking thats what it is and i already tried to decarbon it by putting water thru the carb and letting it steam clean it with no luck. any ideas?
12-16-15, 06:36 AM
#6
Depends upon your setup and your flexibility.
The exhaust port is level to the ground.
Small flashlight and mirror.
Image of a rotor housing.
The big hole is the exhaust.
The little hole is the spark plug.
Other image is a view of 12a with the exhaust manifold removed.
You can see the exhaust port open in the rear (left) and the rotor in the front (right).
The exhaust port is level to the ground.
Small flashlight and mirror.
Image of a rotor housing.
The big hole is the exhaust.
The little hole is the spark plug.
Other image is a view of 12a with the exhaust manifold removed.
You can see the exhaust port open in the rear (left) and the rotor in the front (right).
12-16-15, 06:59 AM
#7
"would it be easier to look into the motor from under the car or top?"
Once you have the exhaust manifold off, with the engine still in the car, it's a pretty tight fit to get your head in between the strut tower and exhaust ports, regardless of whether you are coming from above or below.
However if you use a mirror to take a look in and a flashlight to light things up, like Tim says, you should be able to clearly see each apex seal as it comes around. Check each one at a time by bringing it to the center of the exhaust port, making sure it looks good and then pushing it down with your finger, it will move if it's not seized up.
On the other hand, if the apex seal is broken, bent or chipped or is frozen in place, that likely the problem.
A couple of notes:
1) a 12A that is running pretty well, with both rotors firing and giving decent power, can still have some frozen apex seals, I guess because when they freeze into place they are still very close to the rotor housings and making a decent seal.
2) given your description of how this happened, I think it would be more likely that the seal was damaged, rather than being frozen in place. Stuck seals happen slowly over time and often don't have obvious effects on engine power; broken seals happen all at once and you are likely to notice a significant change in power.
3) best not to use your finger while rotating the engine to locate the apex seals as they come around to the exhaust ports, you might chop it off.
Once you have the exhaust manifold off, with the engine still in the car, it's a pretty tight fit to get your head in between the strut tower and exhaust ports, regardless of whether you are coming from above or below.
However if you use a mirror to take a look in and a flashlight to light things up, like Tim says, you should be able to clearly see each apex seal as it comes around. Check each one at a time by bringing it to the center of the exhaust port, making sure it looks good and then pushing it down with your finger, it will move if it's not seized up.
On the other hand, if the apex seal is broken, bent or chipped or is frozen in place, that likely the problem.
A couple of notes:
1) a 12A that is running pretty well, with both rotors firing and giving decent power, can still have some frozen apex seals, I guess because when they freeze into place they are still very close to the rotor housings and making a decent seal.
2) given your description of how this happened, I think it would be more likely that the seal was damaged, rather than being frozen in place. Stuck seals happen slowly over time and often don't have obvious effects on engine power; broken seals happen all at once and you are likely to notice a significant change in power.
3) best not to use your finger while rotating the engine to locate the apex seals as they come around to the exhaust ports, you might chop it off.
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im gonna see what i can get done today ill let you know how it goes
12-16-15, 02:17 PM
#9
Full Member
Thread Starter
Depends upon your setup and your flexibility.
The exhaust port is level to the ground.
Small flashlight and mirror.
Image of a rotor housing.
The big hole is the exhaust.
The little hole is the spark plug.
Other image is a view of 12a with the exhaust manifold removed.
You can see the exhaust port open in the rear (left) and the rotor in the front (right).
The exhaust port is level to the ground.
Small flashlight and mirror.
Image of a rotor housing.
The big hole is the exhaust.
The little hole is the spark plug.
Other image is a view of 12a with the exhaust manifold removed.
You can see the exhaust port open in the rear (left) and the rotor in the front (right).
"would it be easier to look into the motor from under the car or top?"
Once you have the exhaust manifold off, with the engine still in the car, it's a pretty tight fit to get your head in between the strut tower and exhaust ports, regardless of whether you are coming from above or below.
However if you use a mirror to take a look in and a flashlight to light things up, like Tim says, you should be able to clearly see each apex seal as it comes around. Check each one at a time by bringing it to the center of the exhaust port, making sure it looks good and then pushing it down with your finger, it will move if it's not seized up.
On the other hand, if the apex seal is broken, bent or chipped or is frozen in place, that likely the problem.
A couple of notes:
1) a 12A that is running pretty well, with both rotors firing and giving decent power, can still have some frozen apex seals, I guess because when they freeze into place they are still very close to the rotor housings and making a decent seal.
2) given your description of how this happened, I think it would be more likely that the seal was damaged, rather than being frozen in place. Stuck seals happen slowly over time and often don't have obvious effects on engine power; broken seals happen all at once and you are likely to notice a significant change in power.
3) best not to use your finger while rotating the engine to locate the apex seals as they come around to the exhaust ports, you might chop it off.
Once you have the exhaust manifold off, with the engine still in the car, it's a pretty tight fit to get your head in between the strut tower and exhaust ports, regardless of whether you are coming from above or below.
However if you use a mirror to take a look in and a flashlight to light things up, like Tim says, you should be able to clearly see each apex seal as it comes around. Check each one at a time by bringing it to the center of the exhaust port, making sure it looks good and then pushing it down with your finger, it will move if it's not seized up.
On the other hand, if the apex seal is broken, bent or chipped or is frozen in place, that likely the problem.
A couple of notes:
1) a 12A that is running pretty well, with both rotors firing and giving decent power, can still have some frozen apex seals, I guess because when they freeze into place they are still very close to the rotor housings and making a decent seal.
2) given your description of how this happened, I think it would be more likely that the seal was damaged, rather than being frozen in place. Stuck seals happen slowly over time and often don't have obvious effects on engine power; broken seals happen all at once and you are likely to notice a significant change in power.
3) best not to use your finger while rotating the engine to locate the apex seals as they come around to the exhaust ports, you might chop it off.
okay guys well i did a physical and feel check and it seems that ONE of the apex seals is stuck but on the right side towards the front of the engine? the left side moves only a little bit and the right side seems pretty stuck down... but the other 2 seals are pretty nice and free
12-16-15, 04:13 PM
#10
Full Member
Thread Starter
well i got some MMO and put it in both rotors and started working all the seals in and out and when i went to the 2nd rotor they were fine but when i went to the 3rd seal it seemed to not be there?.. all i felt was the spot where one was supposed to be i think like my finger sunk into it and i felt something there maybe the spring? how does one blow out a seal
12-16-15, 08:02 PM
#13
Once you have the exhaust manifold off, with the engine still in the car, it's a pretty tight fit to get your head in between the strut tower and exhaust ports, regardless of whether you are coming from above or below.
However if you use a mirror to take a look in and a flashlight to light things up, like Tim says, you should be able to clearly see each apex seal as it comes around. Check each one at a time by bringing it to the center of the exhaust port, making sure it looks good and then pushing it down with your finger, it will move if it's not seized up.
However if you use a mirror to take a look in and a flashlight to light things up, like Tim says, you should be able to clearly see each apex seal as it comes around. Check each one at a time by bringing it to the center of the exhaust port, making sure it looks good and then pushing it down with your finger, it will move if it's not seized up.
I just got one of these cheapo borescopes and they are GREAT. Perfect for this kinda work. Just plug it into your laptop and scope away. Shoot at 10 meters you could plug it into your desktop and look at your car in your garage
12-16-15, 08:32 PM
#14
5 10M 6LED USB Waterproof Endoscope Borescope Snake Inspection Camera Scope 7mm | eBay
I just got one of these cheapo borescopes and they are GREAT. Perfect for this kinda work. Just plug it into your laptop and scope away. Shoot at 10 meters you could plug it into your desktop and look at your car in your garage
I just got one of these cheapo borescopes and they are GREAT. Perfect for this kinda work. Just plug it into your laptop and scope away. Shoot at 10 meters you could plug it into your desktop and look at your car in your garage
12-16-15, 09:29 PM
#15
Full Member
Thread Starter
Depends upon your setup and your flexibility.
The exhaust port is level to the ground.
Small flashlight and mirror.
Image of a rotor housing.
The big hole is the exhaust.
The little hole is the spark plug.
Other image is a view of 12a with the exhaust manifold removed.
You can see the exhaust port open in the rear (left) and the rotor in the front (right).
The exhaust port is level to the ground.
Small flashlight and mirror.
Image of a rotor housing.
The big hole is the exhaust.
The little hole is the spark plug.
Other image is a view of 12a with the exhaust manifold removed.
You can see the exhaust port open in the rear (left) and the rotor in the front (right).
alright guys how long does an average rebuild take? just the apex seals and other seals if they are bad im on a budget but ill do them if i have too...i pretty sure my side seals are shitting the bed too
12-16-15, 10:24 PM
#16
^^^ granted I had newish rotors/housings cleaned and ready to go.
12-16-15, 10:28 PM
#17
Full Member
Thread Starter
hmm thats not bad at all i guess do you think i could get away with just replacing the broken apex seal and clean all the other seals in the motor if they arent bad? im not looking to have this car last me forever or anything just a few years this is just a car for fun for now
12-16-15, 10:48 PM
#18
I'm pretty knowledgeable with a wrench and a rotary though.... First rebuild might take you a month.
Some tips for the first timer... if it looks un-usable don't reuse it. and buy NEW apex seals (don't f around). and oil pan gaskets are for suckers.
Just start with the fel-pro gasket set, and a set of apex seals from atkins. Once you tear the engine down you'll know if you need rotors or housings or even an e-shaft.
Some tips for the first timer... if it looks un-usable don't reuse it. and buy NEW apex seals (don't f around). and oil pan gaskets are for suckers.
Just start with the fel-pro gasket set, and a set of apex seals from atkins. Once you tear the engine down you'll know if you need rotors or housings or even an e-shaft.
Last edited by Qingdao; 12-16-15 at 10:51 PM.
12-16-15, 11:00 PM
#19
Full Member
Thread Starter
I'm pretty knowledgeable with a wrench and a rotary though.... First rebuild might take you a month.
Some tips for the first timer... if it looks un-usable don't reuse it. and buy NEW apex seals (don't f around). and oil pan gaskets are for suckers.
Just start with the fel-pro gasket set, and a set of apex seals from atkins. Once you tear the engine down you'll know if you need rotors or housings or even an e-shaft.
Some tips for the first timer... if it looks un-usable don't reuse it. and buy NEW apex seals (don't f around). and oil pan gaskets are for suckers.
Just start with the fel-pro gasket set, and a set of apex seals from atkins. Once you tear the engine down you'll know if you need rotors or housings or even an e-shaft.
12-17-15, 07:37 AM
#20
Waffles - hmmm good
iTrader: (1)
Depends on how often you want to practice rebuilding the engine. Reusing inspec parts is ok
but the seals and springs you probably at least want to get new. Personally I wouldn't mix old
apex seals with new or another used one.
but the seals and springs you probably at least want to get new. Personally I wouldn't mix old
apex seals with new or another used one.
12-17-15, 07:57 AM
#21
Sorry for the bad news Brian, but you can look at it in a good way: You've already got the skills needed to do the rebuild, you'll get to know the rotary up close and personal and in the end you'll have a fresh rebuild that should be good for years.
There are some very good rebuild videos and tutorials for rotary engines around, I'd take a look at some of those first to get an idea of what's involved. The first time around, it will be slow, they have a bunch of quirks you need to learn about and discover, but once you know what you're doing a couple days would be reasonable if you have all the parts (10 hours if you're really good at it).
But having all the parts is the rub, you won't know what you need until you tear it down. But figure at least a gasket set and rotor kit, so budget $800-$1000 there.
And then rotors and rotor housings (this is the tricky part). Since you lost an apex seal the chances are pretty good the rotor housing it was in is toast and it may have taken the rotor with it. Usually in these cases you can see images of the broken apex seal embedded in the rotor face where they crunch between the housing wall and rotor (I have one rotor with a perfect indention of the smaller end piece from an apex seal, kind of cool actually). Good used rotors and housings for the 12A are hard to find and new ones aren't available, so this is usually the limiting factor on the feasibility of a rebuild.
That endoscope might give you some idea of how bad it is before doing the tear down (I just put in an ebay order myself, thanks for the heads up James) but I don't see that changing anything, only when you have it out on the bench in pieces and speced up will you know what you need.
Let us know how it goes!
There are some very good rebuild videos and tutorials for rotary engines around, I'd take a look at some of those first to get an idea of what's involved. The first time around, it will be slow, they have a bunch of quirks you need to learn about and discover, but once you know what you're doing a couple days would be reasonable if you have all the parts (10 hours if you're really good at it).
But having all the parts is the rub, you won't know what you need until you tear it down. But figure at least a gasket set and rotor kit, so budget $800-$1000 there.
And then rotors and rotor housings (this is the tricky part). Since you lost an apex seal the chances are pretty good the rotor housing it was in is toast and it may have taken the rotor with it. Usually in these cases you can see images of the broken apex seal embedded in the rotor face where they crunch between the housing wall and rotor (I have one rotor with a perfect indention of the smaller end piece from an apex seal, kind of cool actually). Good used rotors and housings for the 12A are hard to find and new ones aren't available, so this is usually the limiting factor on the feasibility of a rebuild.
That endoscope might give you some idea of how bad it is before doing the tear down (I just put in an ebay order myself, thanks for the heads up James) but I don't see that changing anything, only when you have it out on the bench in pieces and speced up will you know what you need.
Let us know how it goes!
Last edited by ray green; 12-17-15 at 08:09 AM.
12-17-15, 06:24 PM
#22
I'd get all 6 apex seals and springs... I wouldn't trust 30+yo hardware; if one broke whos to say the others won't follow suit. Also, they get sold in sets of 6.
Here is a picture of my throat.... EWWW GROSS!!
Here is a picture of my throat.... EWWW GROSS!!
Last edited by Qingdao; 12-17-15 at 06:26 PM.
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