Exactly what the title asks, I took a video of me compression testing the engine today and would like somone who has experience with a blown apex to take a look at them and confirm for me before i buy the new engine. I would host the videos if i could but i dont have a site so i will just email them to whoever would be willing to look at them...

thanks very much, Michael

 

I can probably tell you by the sound of it, if the vid is clear enough. I hear blown ones all day long, unfortunately

 

What type of compression tester are you using. I just did this 2 months ago with a cheapy from autozone. It's relatively easy since what you're looking for is three even pulses on the gauge. In my case with the motor cold I got three even 90 psi pulses on the rear. and then 90...90... 0 on the front. Key is to make sure the pulses are pretty close in pressure as well elapsed time

 

Are you sure that wasnt 90, 0, 0 ? I didnt think you could lose compression on 1 face.

-Ben

 

Yeah, it'd be pretty rare to see 0 on only one face...that was probably 90-0-0; eve 90-60-60 isn't uncommon...90-90-0 would have to be a corner seal or side seal, both of which are VERY uncommon to break, if not hit by something else (like pieces of apex seal) first.

 

You can lose compression on one face only by having a damaged side seal.

Sonny

 

Side seals generaly don't up and break. They are actually quite strong, 95% of their height is compressed into the rotor, and with only a few thousandths of an inch worth protruding outward to make the seal, it is very hard to break them. They do stick a lot, however, and this can cause low compression, but not all at once on an otherwise fine running engine that hasn't been allowed to sit for a long time.

 

Good info, man. I like your avatar. lol

Sonny:

 

actually I'm sorry you guys are right I looked back and looked at my log I made and actually what I saw was 90... 40 or so not a strong pulse, and then nothing.
-Nic

 

Before I did the test that is what I had expected to see, but the weird part was when I did do the test I saw the compression fall off as I described. Logically thinking it doesn't make sense, and I don't know why, but that's what I saw as I tested it.
-Nic