Interesting Findings on the Dead Engine....
04-08-02, 05:29 PM
#1
Old [Sch|F]ool
Thread Starter
Interesting Findings on the Dead Engine....
I got my dial calipers back yesterday, so naturally before I unpack everything else, I go down to the Evil Secret Underground Shop (my basement) and mic' out some stuff on the engine. What I found was fascinating.
I previously said that the apex seal springs were flattened. Well, I made that statement because the apex seals were sitting below the rotor surface. Upon measuring three of the four remaining seals and their springs, I found them all to be well within spec. Intrigued, I measured length - precisely at as-new spec. So I went to put them back in the rotor, and sure enough they stayed extended instead of falling flush with the rotor tip. In short, the apex seals on the #2 rotor appear fine, they were only stuck down in their grooves because they were carboned up!
I wouldn't use them again, though, without a thorough inspection (X-raying, Magnafluxing) and for that much trouble to check each seal out, new ones are $30 or so apiece. I couldn't measure the seals on the front rotor because they are hammered into the grooves. The apex seal that originally died appears to have shattered - if it had stuck in its bore due to carbon buildup, I'd think it would have left a telltale gouge across the entire rotor housing and the tip of the rotor would have been deformed. The only damage to the rotor is due to metal chunks hitting it, likewise for the rotor housing.
I still feel that overrevving was the cause of failure. However I have a new respect for carbon, even stronger than what I already had. Meanwhile, I plan on getting a quart of ATF and putting it in a small pan, and partially soaking the rotor for a few days, just so I can see the effect. Should be interesting.
I previously said that the apex seal springs were flattened. Well, I made that statement because the apex seals were sitting below the rotor surface. Upon measuring three of the four remaining seals and their springs, I found them all to be well within spec. Intrigued, I measured length - precisely at as-new spec. So I went to put them back in the rotor, and sure enough they stayed extended instead of falling flush with the rotor tip. In short, the apex seals on the #2 rotor appear fine, they were only stuck down in their grooves because they were carboned up!
I wouldn't use them again, though, without a thorough inspection (X-raying, Magnafluxing) and for that much trouble to check each seal out, new ones are $30 or so apiece. I couldn't measure the seals on the front rotor because they are hammered into the grooves. The apex seal that originally died appears to have shattered - if it had stuck in its bore due to carbon buildup, I'd think it would have left a telltale gouge across the entire rotor housing and the tip of the rotor would have been deformed. The only damage to the rotor is due to metal chunks hitting it, likewise for the rotor housing.
I still feel that overrevving was the cause of failure. However I have a new respect for carbon, even stronger than what I already had. Meanwhile, I plan on getting a quart of ATF and putting it in a small pan, and partially soaking the rotor for a few days, just so I can see the effect. Should be interesting.
04-08-02, 05:43 PM
#2
Yes that is interesting, 
If someone dont let me know something on this 12A I got, im gonna buy new seals for it and rebuild it and find a good 12A car with a bad motor and put it in there...Are those springs really that high, I though they were like $6/ea?
Well good luck dude, and how did the job interview go. I forgot to ask...
If someone dont let me know something on this 12A I got, im gonna buy new seals for it and rebuild it and find a good 12A car with a bad motor and put it in there...Are those springs really that high, I though they were like $6/ea?Well good luck dude, and how did the job interview go. I forgot to ask...
04-08-02, 05:59 PM
#5
Old [Sch|F]ool
Thread Starter
No, $30 is for the SEALS. I'd re-use the springs but I can't be certain that the seals aren't fatigued and ready to break. For the effort of determining that, it'd be easier to just get new ones.
I'm not concerned about MMO, just the ATF. I want to see how well the detergents handle the carbon.
I'm not concerned about MMO, just the ATF. I want to see how well the detergents handle the carbon.
04-08-02, 06:03 PM
#7
Originally posted by peejay
No, $30 is for the SEALS. I'd re-use the springs but I can't be certain that the seals aren't fatigued and ready to break. For the effort of determining that, it'd be easier to just get new ones.
I'm not concerned about MMO, just the ATF. I want to see how well the detergents handle the carbon.
No, $30 is for the SEALS. I'd re-use the springs but I can't be certain that the seals aren't fatigued and ready to break. For the effort of determining that, it'd be easier to just get new ones.
I'm not concerned about MMO, just the ATF. I want to see how well the detergents handle the carbon.
Didnt do a damn thing...Only thing that works is Kerosene and paint thinner on a rag with a shitload of scrubbing...!!!
Oh carb cleaner and old pot scrubby does pretty well too..
Last edited by MIKE-P-28; 04-08-02 at 06:17 PM.
Thread
Thread Starter
Forum
Replies
Last Post
streetlegal?
New Member RX-7 Technical
13
03-17-22 02:46 PM