I Hadnt Thrown An Apex Seal After All..... Makes A Change!!!

[antnicuk]

Took my engine apart this morning,  after it died on the way to rotorstock.  I was flat out in 4th just as boost was hitting 15psi at about 4.5 to 5k rpm when it died on me, nursed it home with what felt exactly like i\'d thrown an apex seal.

Did a basic compression test and found i had full compression on the back rotor but only one puff on the front which indicated that i had one seal gone.

Took the engine out and stripped it to find all my seals in place..........but one of the front seals was stuck right in the rotor groove (hence no compression). I gently prized it out. The seal is fine, but the rotor had a very tiny little lip and a slightly uneven surface at the top of the groove, this is what was holding the seal wedged in the rotor.

There is a small score in the rotor housing consistent with the damage on the rotor.

I have spoken to a couple of people..   (thanks Tim and Jason for your advice)

I checked my eccentric shaft which is spot on, my rotor bearings are not worn at all, my front main bearing has very little wear and my rear one has a little whisp of brass showing.

Having checked my apex seal groove on the rotors, there seems to be slightly less than the recomended clearence but they do move freely,...... just

Does anyone have any advice or ideas before i put it back together.

Many thanks and regards

tony
:confused:

[Carl]

Hi Tony,
2 things,
1.Is the engine very carboned up?A small piece of carbon could have fallen off and jammed the seal into the rotor.
2.You may have had detonation that closed the apex seal groove up slightly causing it to be too tight and thus holding the seal.

Are there any signs of detonation?If you want to know where to look and how to spot it give me a call.

Kind regards
Carl

[JayDee]

The groove is very uneven at either end, I dont think detonation would cause this. If it is det and Tonys seal can outlive the rotor there dont seem any need for ceramics:confused:   ( Tony what seals are you running )

Jaydee

[antnicuk]

ATKINS.....................cheap and chearfull......  will probably go for mazda ones once i can finally destroy these. more boost required me thinks!!    

[Glenn Butcher]

Sounds interesting!  At what part on the rotor housing was the score mark?

[antnicuk]

it was right on the edge of the exhaust port, about an inch long running down to the top corner of the port.
Its staying cos they are too damn expensive for new ones...

just out of interest glen,  how much are new rotor housing in Aus?
they are in the region of 4 to 5 hundred wuid over here including blairs pocket money (vat)
regards

tony

[Adam]

rotor housings are 331 plus the vat each over here, thats from mazda.  the mid plate is about the same but the end plates are about 210 plus vat....

adam

[Glenn Butcher]

Originally posted by antnicuk
it was right on the edge of the exhaust port, about an inch long running down to the top corner of the port.
Its staying cos they are too damn expensive for new ones...

just out of interest glen,  how much are new rotor housing in Aus?
they are in the region of 4 to 5 hundred wuid over here including blairs pocket money (vat)
regards

tony

Interesting, so did you find out anything further? any other ideas?

Reason I asked about any scoring was because I wondered if anything had gone through the engine - jamming the seal?

A couple of unusual failures I have come across are, an apex seal being stuck (car had been sitting around for a while) my friend managed to unstick one of the seals with some WD40 and a screwdriver through the exhaust port.

Another friend actually had a bolt go through an engine, not damaging anything! (came off the webber carby as he was tuning it) - we all said OH NO at the time! but engine kept going for a number of years.

Yours does sound very strange indeed.

Not sure of the cost in Oz, I\'ll see what I can find out for you - from memory they are pretty expensive out here.