turboaddict

So the latest chapter on my rotary rail is that i lost compression on the rear rotor. Ran it through first gear, shifted and then felt like i had lost spark. Checked spark and then a pop test showed great compression in the front rotor and 0-0-15 psi in the rear. Pulled the turbo and manifold off to check out and found all 3 rear apex seals stuck down and no damage evident. All seals were in factory specs for clearance and the front rotor is all good. Motor has about 5 hours on it now and has run great since the carb was rebuilt.
So the question is..... What happened and what can i do to fix it without tearing into the motor?

The setup:
13b
fc irons rotors and housings
all Atkins internals
3mm apex seals
it has this complete aftermarket turbo kit: http://t1.gstatic.com/images?q=tbn:A...wH8XrU8nQnISQQ
6 psi boost
air to air intercooler

Thanks!

Brodie121

iTrader: (8)

sometimes you cannot see the damage.
It could be hidden off to the side of the exhaust port.
My engine was like this.

turboaddict

okay an update used a borescope and examined both side of all the rotor faces. apex seals undamaged and no obvious damage to the housing or rotor.
Ideas?

Turbo II FC

iTrader: (14)

Take it apart and replace springs? Did you use new springs when you rebuilt the motor?

turboaddict

yes rebuilt using an full atkins kit...

RotaryEvolution

iTrader: (30)

get it running and do a water treatment on the affected rotor, or put a few ounces of MMO into the leading rear rotor spark plug hole, reinstall the plug, turn it over for a few seconds without starting it and let it sit over night. start it up after the day of sitting and cross your fingers. sometimes there's just nothing you can do to unstick the seals depending on what happened to the engine. it could have lightly deflected and bounced the rotor tips off the housings, thus pinching the seals if it was over-revved.

i'm leaning on the last guess, it shouldn't have enough carbon in the engine in only 5 hours of run time for the seals to be sticking for any natural reasons. if that is the case then there probably isn't any unrepairable major damage to the engine but it will need to come apart again to re-clearance the rotor slots.

turboaddict

Yeah... Just got done pulling it out. I put marvel in it a week ago and tried to work them but they still show the same symptoms. I'll know in the next day or so what the story is internally, when i get the rear housing off.
So if they deflect the rotor actually contacts the housing and "dents" the gap closed? How would i go about re-gapping them ?

diabolical1

iTrader: (3)

you may be able to use a file.

maREX7

so did this got fixed after all? Ive fellow with FD3S primary rotor is absolute fine 120psi total compression and 70+psi 3 even bounces on primary rotor, while, secondary will show total of 70psi and bounces about 30-40psi only, but bounces are all even , it looks like the apex seals are stuck. This happened withing 48hours after the oil change from one brand to the other. was castrol gtx 10w40 and went to something other 10w40, engine was just under 20k kms since rebuilt and wasnt abused, always regular oil changes every 2k kms or less etc etc, not over revved since rebuilt. It may run sometimes feels like rear rotor comes back to life for a very short time like few seconds vie few thousand rpm, and then like it misfires and overfuels, cant burn the fuel coz no compression...
apex tips sound even swooshing with sparkplug out... I wonder if some good wngine flush would help out to unstick the seals... thats what we suspect... any ideas guys??

flaco

iTrader: (7)

after you closed the engine , how long you let it sit ??? did you put some fluid down while sitting ?

maREX7

it wasnt rebuilt by ourselves but by previous owner, it made approx 5k kms while with us, and everything was just absolutely perfect untill the oil change... then this started to happen. when you say how ling we let it sit and did we put any fluid what do u mean by that exaclty?

Thanks

flaco

iTrader: (7)

o so the car was fine all day then you changed the oil and when you got it started after that you noticed the car lost compression ?

or a couple of hours/days is when it all started happening ??? right before the car started acting up did you noticed any type of vibration coming from the engine?

maREX7

I will have to ask my fellow, but as far as I know car was acting weird since oil change basically after hours since the change... I will verify all little details and will get back in hour or so. We dont wana do teardown if it can be avoided with some maintenance wais from outside of the motor...