Stupid question from a Noob : How do you know when your apex seals are (out, done, cooked, blown, etc) I have a 1980 base that is a project car. I only move it out of the garage as needed, about once every two weeks. However, it is difficult to start, and blows clouds of blue smoke out the exughst (sp) upon start-up. The smoke does go away after running it for about 10 minutes, and I'm not leaking anything fluid wise.

Thanks in advance!
Tazzman69

 

they break ****. it sounds like bad oil control seals to me.

 

I agree. Check out the Lucas Oil Stabilizer thread and you might find some help for it.

https://www.rx7club.com/1st-generation-specific-1979-1985-18/lucas-oil-stabelizer-506028/

Apex seal gone = remove top spark plug and turn over engine. You will hear PSSST, pause, pause, PSSST, pause, pause, etc...

A good engine will have three solid PSSST sounds as the compressed air comes out of the spark plug hole. Need to check a front and a rear spark plug to cover both rotors.

 

What happens? If your lucky it just cracks and you loose compression... If you have shitty luck... this:

 

CARNAGE!!!!

Piston motors can blow up pretty spectacularly too... here's a SBC that got a 10k rpm 3rd gear miss.

 

yeah. that could happen too, but more normal for rotarys
10k on a piston probably added to that.

 

As they say, 'It blowed up real good'. Both of you did outstanding jobs.

When an apex seal goes, the engine will run rough enough that it will look like it's trying to jump out of the engine bay if the motor mounts are bad. They also sound like a weedeater running on 1/2 cylinder. Your oil control seals are going/gone.

 

The blue smoke on startup is pretty common and isnt too big a deal so long as it goes away.If it smokes continuously(and it will eventually)....then its time for a tear down.You have to decide how much smoke is too much.

The hard starting is likely along the same lines as the smoke,the engine is a little tired.Weak compression on an already low compression engine,will make startup difficult.And,cold rotaries often need a lot of choke to fire up,and excess fuel down the intake can wash the oil off the housings,hampering the seal's ability to hold compression.Once the engine does fire up,its always best to drive/rev it up a bit and be sure it reaches running temp.Just letting it idle in the driveway,then shutting down,can make the next startup even more difficult.

 

Yah, 10k on an old V8 like that creates terrible valvetrain stability issues, runs the oil pan dry, floats valves, throws rods (at the bolts usually), cracks piston skirts, walks crankshafts, and does all sorts of BAD BAD things. That motor was a little 283 I ran for awhile. It ran 13's and got pretty good gas mileage. I had a 4 speed, was powershifting at the dragstrip, and missed 3rd gear. The motor was all done at 6200 or so. It buzzed up to 10k by the time I dumped it into 1st, went OH ****! stuck the shifter back into neutral and left my foot on the gas the whole time out of force of habit

KABOOM! Threw 4 connecting rods, cracked the block, walked the crank about a half inch into the back of the block, bent every push rod, lost all my valves, cracked my heads, and generally tore **** up.

Kev

 

^dood thats some awesome ****^

 

but when your driveing? what does the loss of compression feel like? Is it something that you can hear in the driver seat? some sort of loud ping or short thoug? What are the keys to identifying a blown apex seal before it causes a total loss of the housing or when an apex seal blows, he housing is allready thrashed?

I wonder if there are any more questions I can think of.

 

take one of your trailing plugs out. i've felt it. feels like someone swapped a lawn mower engine in your car...

 

still looking for the tall tale sign of a blown apex seal. Would a drop in the oil pressure guage signify a blown apex seal? What about something like just no power? When an apex seal is blown.. will the housing need to be replaced? or is that just a matter of luck?

 

Compression test is the best diagnostic tool. No, oil pressure should not drop. If the seal cracked and stayed in the groove, housings are often still good. If they broke and came out of the groove, usually both the housing and rotor need replaced.

 

By the time the Seal Comes apart it is to late to save any part of the slice of the engine. They spin around a few times before making out the exheaust and makes a real mess of the housing and rotor, Most times Breaking the other two seals.

The one I had go when driving went to shaking and really let you know that it was broke.