an RX8er's rebuild thread
07-10-2012, 11:03 AM
#1253
Just a little fun fact...
Chatter marks, compression, bearing wear, wear on the irons. All are most likely steaming from an unbalanced assembly. I am coming to the conclusion that the original reman's assembly was not matched right and overtime warped the eshaft.
My theory is the new bearings were placed in and the now the previosuly warped eshaft has caused even more damage in less time. This is due to the fact that it no longer has its seat and needs to make a new one in the bearings.
It's a long shot but I know of at least 3 people running Atkins seals with no issues. This is a reoccurring problem and the only pieces we have no taken out of the equation is the assembly.
Austin in the spirit of saving money I suggest you send off your rotating assembly for balancing. reuse an old housing from your previous engine versus getting a Goopy coating. The folks at Goopy knows their stuff and I had a very long chat with them at sevenstock.
At this point I feel slightly responsible as well and want to get this thing back online ASAP.
Chatter marks, compression, bearing wear, wear on the irons. All are most likely steaming from an unbalanced assembly. I am coming to the conclusion that the original reman's assembly was not matched right and overtime warped the eshaft.
My theory is the new bearings were placed in and the now the previosuly warped eshaft has caused even more damage in less time. This is due to the fact that it no longer has its seat and needs to make a new one in the bearings.
It's a long shot but I know of at least 3 people running Atkins seals with no issues. This is a reoccurring problem and the only pieces we have no taken out of the equation is the assembly.
Austin in the spirit of saving money I suggest you send off your rotating assembly for balancing. reuse an old housing from your previous engine versus getting a Goopy coating. The folks at Goopy knows their stuff and I had a very long chat with them at sevenstock.
At this point I feel slightly responsible as well and want to get this thing back online ASAP.
I can’t use the old housing as they were cracked remember. I sent Goopy an email this morning as well as having some communication with Charles. I want o verify e-shaft is jacked and go from there. depending on the outcome of all this measurements I am thinking of going to 1-piece apex's.....but for right now it’s just a thought.
REC Services | Balancing Services | Rotating Assembly Balancing
I have another link somewhere in this build thread but haven’t found it yet...I remember it being like $500
07-11-2012, 08:37 PM
#1260
so just for reference....NRG hood dampers for the rx8 on really only in carbon fiber.....even though they sell them in chrome. Chrome is too freaking powerful and will buckle your hood (ask me how I know)......CF is 1/2 power (shady I dont know how you got yours in chrome)
07-11-2012, 09:54 PM
#1261
this may help--i am running the rx7 mazda turbo seals--almost twice as tall but remains 2 mm wide
http://www.google.com/imgres?q=diffe...9,r:0,s:0,i:77
now think of a post in the ground--which one is easier to move back and forth--the post that is 1 foot in the ground or the post that is 2 foot into the ground?.
2mm tall apex seals--thats the ones I am sold on.
Do not get 3 mm seals for a street driven car--is what I have been told by many a rotary builder
http://www.google.com/imgres?q=diffe...9,r:0,s:0,i:77
now think of a post in the ground--which one is easier to move back and forth--the post that is 1 foot in the ground or the post that is 2 foot into the ground?.
2mm tall apex seals--thats the ones I am sold on.
Do not get 3 mm seals for a street driven car--is what I have been told by many a rotary builder
I suppose I should feel proud for being plagarized ...
07-11-2012, 10:01 PM
#1262
Unlike a piston engine, the only thing that separates the flame front between the rotor chambers on a Wankel is the apex seal. Think about what happens if it gets by one apex seal into the next proceeding chamber. Some people profess that rotor sealing is not that critical with rpm, but it is actually more critical in that regard.
07-12-2012, 12:58 AM
#1265
I'm not sure how it works, but I know if your starter is bunk and isn't cranking the correct RPM's your compression will read lower.
The lower the cranking speed the lower the compression. all that needs to be factored in when reading the compression results.
Not sure if thats relevant or not, I am half asleep.
The lower the cranking speed the lower the compression. all that needs to be factored in when reading the compression results.
Not sure if thats relevant or not, I am half asleep.
07-12-2012, 07:37 AM
#1266
please help me understand 
based on the breakin proceedure we discussed earlier in the thread the higher RPM were supposed to supply more back pressure for seating ther seals but I dont think it was the RPM we were looking for more of the quality of the combustion.
If the AFR is 14.7 then the pressure in the chamber is the same regardless of RPM, now under full throttle the AFR changes thus changing the pressure (more pressure behind the seal means "higher compression").....right?
based on the breakin proceedure we discussed earlier in the thread the higher RPM were supposed to supply more back pressure for seating ther seals but I dont think it was the RPM we were looking for more of the quality of the combustion.
If the AFR is 14.7 then the pressure in the chamber is the same regardless of RPM, now under full throttle the AFR changes thus changing the pressure (more pressure behind the seal means "higher compression").....right?
07-12-2012, 11:13 AM
#1270
I don't have the time to comprehend all of this right now. But I think your answer is in this book somewhere.
http://www.personal.utulsa.edu/~kenn...n/chapter7.pdf
http://www.personal.utulsa.edu/~kenn...n/chapter7.pdf
07-12-2012, 11:50 AM
#1271
cool thanks shady
9k...just cleaning rotors, seals and springs....corner seals suck if I didnt already say that
just FYI
RX-8 Apex Seals Slot to Taller Rx7 Apex Seal
9k...just cleaning rotors, seals and springs....corner seals suck if I didnt already say that
just FYI
RX-8 Apex Seals Slot to Taller Rx7 Apex Seal
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