ok first of all 85 gsl-se block all stock

now I did a compression test with the starter running at 250rpms like it should

front rotor is great

go to do back rotor and I get two bounces and then one nothing two bounces a nothing etc.... so I think broken side seal but then as I'm about to signal my cohort to stop turning over the engine it starts three bounces.... so I think well I guess it was stuck lets let it turn over for a while and see what happens... it runs good so I am about to signal my cohort when bam! no compression at all from any face! so... I'm thinking WTF and then I get compression again on all three... so I'm not sure what the hells going wrong I've rebuilt several motors before and without question this one is going to be rebuilt for safe measure (also I've been meaning to move to higher compression rotors and port the engine) but does anyone know what could be causeing the problem...?

my only guess is that it is screwed up side seals that keep sticking and unsticking...

got the engine for free so its no big deal as I still have my other engine in my rx with 120+ psi on both rotors after 160k miles, gotta love first gen reliability!

 

whats odd is.... if you blew one seal. it'll take out 2 sides of compression.... so ya. wtf?

 

Side Seal?
thats my guess

 

I'm sure its nothing a little seafoam wouldn't fix.

 

Yea maybe seafoam would repair it I've had wondrous results with it before but there are numerous things I want to do with the engine internals anyways so I'm just goign to rebuild it... it occurred to me though that it may be because the engine has been sitting and even though I put a little oil in the engine before turning it over its just a little dry...

 

blown side seal = two compression readings
blown apex = one compression reading

Are you sure your compression tester is not the problem? It seems strange that it (the engine) would bounce back and forth between compression and no compression.

 

Yea I checked the compression tester on my other engines and it acted normal on all of them...

 

Use some MMO.

 

Good idea jeff before I take it apart for the rebuild I'm going to try that and see if I can get some good compression out of it... just for future refrence

 

Tried the MMO and after turning over for a few seconds I was able to get about 90 on both rotors... If I was going to run it I would probably dump some seafoam in it and see how things are doing in a week or so... I guess the side spring seals were just dry and stuck... Thanx everyone!

 

the seals could be gummed up with carbon, causing a situation similar to what ur seeing. Try some decarbonizing tricks and see what happens.

 

I'm glad the MMO helped. The next step is to fire it up and drive it around to clear out the MMO and any loose carbon. Then do another compression test and see whether the results are now consistant.

 

I'm curious. How did it go with the compression results and the stuck side seal?

 

Silence usually indicates success... or a long trip down a short pier...