Rebuilding Questions For The Gurus
07-24-08, 09:23 AM
#1
Rebuilding Questions For The Gurus
So, Im about to attempt to rebuild my first rotary engine. Its a 12A that I will be street porting with RB templates, and using an Atkins level C kit for the assembly. I have rebuilt a piston engine or two in my time to say the least, and worked as a mechanic for a few years, so Im sure I can manage. I just have some seemingly silly questions about the rotaries however...
I noticed reading through the FSM that they mention to use engine oil to coat surfaces and such during assembly. When I build my piston engines, I usually dont use engine oil, and instead use engine assembly lube since it "sticks" to things a little better and doesnt "run out" of places. Is it ok to use this stuff in there instead on the bearings, seals, etc that call for engine oil so they will "stick" in place? I really dont see why not, but thought I would ask. I plan to still use oil to coat the housings and plates of course.
Also, I noticed that they talk about using petroleum jelly to hold seals in place on the rotors. Im sure that if I can use the assembly lube, I can accomplish this as well without the jelly. Good idea? I plan to still use the Jelly for the coolant seals and what not since I dont want that assembly lube floating around in the cooling system however, is that how its typically done?
Im sure I will have a few other questions, but these are all I can think of for now. Any input you have would be nice! Feel free to throw out tips or whatever as well. Thanks in advance!
~T.J.
I noticed reading through the FSM that they mention to use engine oil to coat surfaces and such during assembly. When I build my piston engines, I usually dont use engine oil, and instead use engine assembly lube since it "sticks" to things a little better and doesnt "run out" of places. Is it ok to use this stuff in there instead on the bearings, seals, etc that call for engine oil so they will "stick" in place? I really dont see why not, but thought I would ask. I plan to still use oil to coat the housings and plates of course.
Also, I noticed that they talk about using petroleum jelly to hold seals in place on the rotors. Im sure that if I can use the assembly lube, I can accomplish this as well without the jelly. Good idea? I plan to still use the Jelly for the coolant seals and what not since I dont want that assembly lube floating around in the cooling system however, is that how its typically done?
Im sure I will have a few other questions, but these are all I can think of for now. Any input you have would be nice! Feel free to throw out tips or whatever as well. Thanks in advance!
~T.J.
Last edited by RotorMotorDriver; 07-24-08 at 09:30 AM.
07-24-08, 10:46 AM
#2
I used assembly lube on my motor when I did it and hopefuly its the last rotary I do for awhile. lube up your rotors bearings and oil control rings good. the hardest part is building up the rotors after thats it is just stacking the engine together. I don't think i lubed the plates but I also built it a few years ago. If you want to lube them stay clear of your coolant seal area. That is my opnion and someone else my tell you the oppsite
07-24-08, 11:45 AM
#4
In the FSM there are places in the housings and irons they recommend putting some type of sealer. I used Ultra Grey for my assembly. I also used it to hold the coolant rings in place. Just make sure you do not get the oil control ring spings mixed up. There is a specific front and rear that needs to be reinstalled correctly. Good luck 
07-24-08, 11:54 AM
#5
Petroleum jelly is known to expand the seals, use silicone or hylomar.
If you are alone in rebuilding it, when you get to putting the intermediate plate on, you ned to move the e-shaft up. Use your knee to push it up the inch or so as you slide the plate over it.
Use superglue on the oil pump key thing, that keeps it from falling out.
When assembling the rotor, leave the apex seals and springs out. Put the rotor in, and the housing around it, then drop your apex seals in, then apex springs under that, followed by the apex corner piece.
All I can think of off the top of my head.
If you are alone in rebuilding it, when you get to putting the intermediate plate on, you ned to move the e-shaft up. Use your knee to push it up the inch or so as you slide the plate over it.
Use superglue on the oil pump key thing, that keeps it from falling out.
When assembling the rotor, leave the apex seals and springs out. Put the rotor in, and the housing around it, then drop your apex seals in, then apex springs under that, followed by the apex corner piece.
All I can think of off the top of my head.
07-24-08, 12:30 PM
#7
I have never used petroleum jelly but racing beat, mazda trix, and mazda dealer ships use the stuff, I suggest using hlyomer or silicon it's sticker and allows less movement of the water seals when he/she is building the motor or putting it together.
The inner bearing on the oil pump is not a big issue but just slap a very thin coat of silicon to hold the bearing in there when he/she is holding it right side up to bolt it up to the front oil cover.
I always, and i make it a religous practice to always oil up all areas of the motor that have metal to metal contact...One could never be to sure or take to many pre-cautions. There is no harm in putting oil on the housings, irons, e-shaft, and rotor bearings, and stationary bearings!!!
Change or update the stationary bearing and rotor bearings is a plus!!!
Make sure you don't mix match all the oil control rings and springs, there designated to certain parts of the rotor and have to be put back in there original place, as well as the side seals and the side seal springs...
Do not re-use the pac mans and corner springs just my two two cents if your going to rebuild, rebuild it right the first time and make the motor last another 100 thousand miles plus...even with a street port!!!
Modification to the oil pressure, very good thing to do, i suggest doing it if he/she is rebuilding a stock to mild or aggressive motor... Smash the rear oil regulator an 1/8th inch or more and shim the front oil regulator with a 1/8th inch spacer. simple cheap modification that can be done within minutes...Hit me up for pics and how too, and i will help you out
When closing the motor silicone the tips of the dowls, also take note of which is the longest dowel it goes in the furthes slot of the motor...Silicone on the tips of the dowels insures any leaks from taking place.
When placing the front oil cover take note not to gunk up the small tiny hole that is used for oil. Keep it clean and clear from any goo or silicone when placing the gasket on...
The inner bearing on the oil pump is not a big issue but just slap a very thin coat of silicon to hold the bearing in there when he/she is holding it right side up to bolt it up to the front oil cover.
I always, and i make it a religous practice to always oil up all areas of the motor that have metal to metal contact...One could never be to sure or take to many pre-cautions. There is no harm in putting oil on the housings, irons, e-shaft, and rotor bearings, and stationary bearings!!!
Change or update the stationary bearing and rotor bearings is a plus!!!
Make sure you don't mix match all the oil control rings and springs, there designated to certain parts of the rotor and have to be put back in there original place, as well as the side seals and the side seal springs...
Do not re-use the pac mans and corner springs just my two two cents if your going to rebuild, rebuild it right the first time and make the motor last another 100 thousand miles plus...even with a street port!!!
Modification to the oil pressure, very good thing to do, i suggest doing it if he/she is rebuilding a stock to mild or aggressive motor... Smash the rear oil regulator an 1/8th inch or more and shim the front oil regulator with a 1/8th inch spacer. simple cheap modification that can be done within minutes...Hit me up for pics and how too, and i will help you out
When closing the motor silicone the tips of the dowls, also take note of which is the longest dowel it goes in the furthes slot of the motor...Silicone on the tips of the dowels insures any leaks from taking place.
When placing the front oil cover take note not to gunk up the small tiny hole that is used for oil. Keep it clean and clear from any goo or silicone when placing the gasket on...
Trending Topics
07-24-08, 01:47 PM
#8
As for the kit, I plan to replace basically everything. Im one of those "while Im in there" people, so Id hate for a rebuild to go south just because I skimped out on one set of seals or something.
In the FSM there are places in the housings and irons they recommend putting some type of sealer. I used Ultra Grey for my assembly. I also used it to hold the coolant rings in place. Just make sure you do not get the oil control ring spings mixed up. There is a specific front and rear that needs to be reinstalled correctly. Good luck
Petroleum jelly is known to expand the seals, use silicone or hylomar.
If you are alone in rebuilding it, when you get to putting the intermediate plate on, you ned to move the e-shaft up. Use your knee to push it up the inch or so as you slide the plate over it.
Use superglue on the oil pump key thing, that keeps it from falling out.
When assembling the rotor, leave the apex seals and springs out. Put the rotor in, and the housing around it, then drop your apex seals in, then apex springs under that, followed by the apex corner piece.
All I can think of off the top of my head.
If you are alone in rebuilding it, when you get to putting the intermediate plate on, you ned to move the e-shaft up. Use your knee to push it up the inch or so as you slide the plate over it.
Use superglue on the oil pump key thing, that keeps it from falling out.
When assembling the rotor, leave the apex seals and springs out. Put the rotor in, and the housing around it, then drop your apex seals in, then apex springs under that, followed by the apex corner piece.
All I can think of off the top of my head.
Good advice with the knee. I was reading that part of the manual going "lift up and set the rotor on at the same time!?". Luckily I have a girlfriend who wants to learn about these motors. She just helped me finish up a rebuild of a Toyota 4 cylinder earlier in the month, haha.
Super glue eh? Never wouldve thought of that... I'll keep it in mind.
Also, thats the method the FSM talks about assembling it. I figured I would just follow their method since its my only real "guide". I plan to get Atkins rebuild DVD also though. I hear its good too.
There is no beehive
I have never used petroleum jelly but racing beat, mazda trix, and mazda dealer ships use the stuff, I suggest using hlyomer or silicon it's sticker and allows less movement of the water seals when he/she is building the motor or putting it together.
The inner bearing on the oil pump is not a big issue but just slap a very thin coat of silicon to hold the bearing in there when he/she is holding it right side up to bolt it up to the front oil cover.
I always, and i make it a religous practice to always oil up all areas of the motor that have metal to metal contact...One could never be to sure or take to many pre-cautions. There is no harm in putting oil on the housings, irons, e-shaft, and rotor bearings, and stationary bearings!!!
Change or update the stationary bearing and rotor bearings is a plus!!!
Make sure you don't mix match all the oil control rings and springs, there designated to certain parts of the rotor and have to be put back in there original place, as well as the side seals and the side seal springs...
Do not re-use the pac mans and corner springs just my two two cents if your going to rebuild, rebuild it right the first time and make the motor last another 100 thousand miles plus...even with a street port!!!
Modification to the oil pressure, very good thing to do, i suggest doing it if he/she is rebuilding a stock to mild or aggressive motor... Smash the rear oil regulator an 1/8th inch or more and shim the front oil regulator with a 1/8th inch spacer. simple cheap modification that can be done within minutes...Hit me up for pics and how too, and i will help you out
When closing the motor silicone the tips of the dowls, also take note of which is the longest dowel it goes in the furthes slot of the motor...Silicone on the tips of the dowels insures any leaks from taking place.
When placing the front oil cover take note not to gunk up the small tiny hole that is used for oil. Keep it clean and clear from any goo or silicone when placing the gasket on...
The inner bearing on the oil pump is not a big issue but just slap a very thin coat of silicon to hold the bearing in there when he/she is holding it right side up to bolt it up to the front oil cover.
I always, and i make it a religous practice to always oil up all areas of the motor that have metal to metal contact...One could never be to sure or take to many pre-cautions. There is no harm in putting oil on the housings, irons, e-shaft, and rotor bearings, and stationary bearings!!!
Change or update the stationary bearing and rotor bearings is a plus!!!
Make sure you don't mix match all the oil control rings and springs, there designated to certain parts of the rotor and have to be put back in there original place, as well as the side seals and the side seal springs...
Do not re-use the pac mans and corner springs just my two two cents if your going to rebuild, rebuild it right the first time and make the motor last another 100 thousand miles plus...even with a street port!!!
Modification to the oil pressure, very good thing to do, i suggest doing it if he/she is rebuilding a stock to mild or aggressive motor... Smash the rear oil regulator an 1/8th inch or more and shim the front oil regulator with a 1/8th inch spacer. simple cheap modification that can be done within minutes...Hit me up for pics and how too, and i will help you out
When closing the motor silicone the tips of the dowls, also take note of which is the longest dowel it goes in the furthes slot of the motor...Silicone on the tips of the dowels insures any leaks from taking place.
When placing the front oil cover take note not to gunk up the small tiny hole that is used for oil. Keep it clean and clear from any goo or silicone when placing the gasket on...
I too tend to lube the crap out of things, its how I was taught. Heck, I mustve used a half quart on the 4 cylinder motor I just put together lubing the cylinders, pistons, rings, etc alone. I have assembly lube on everything else (all the bearings).
I also dont plan to re-use anything. As I stated, I dont want this thing to die a month later because I skimped out on a seal. Id rather have it die a month later because of a housing failure and lose compression. Then I can hopefully reuse all my seals with a new housing so I wont be reusing the seals twice so to speak.
I need to read up more on the oil PSI modification. This is something I planned to do. If you could direct me more on what it is I need to do, that would be great!
Overall, some great input from you guys. If you think of anything else, or have any other suggestions, let me know. Im an open book so to speak. Thanks again.
~T.J.
07-24-08, 03:23 PM
#9
I found this book to be incredibly valuable for my first rebuild, even though I was not doing anything in the way of mods:
http://foxed.ca/rx7manual/manuals/ho...20your%20rx-7/
I lucked into a paper copy of it (this was pre-web days, people!) after it had gone out of print, and it probably has more grease and margin notes in it than my paper copy of the FSM does.
Prepare to cuss the center iron while trying to settle it... the heat helps it go on, I think.
Know that the "eccentric shaft free end play" must be FREE play; no prying or pressure, it should just slide for those critical couple thousandths of an inch. The pictures of this procedure can be misleading, and getting this adjustment right is the key to longevity in your build. Not knowing this cost me a rebuild and some expensive parts.
If you haven't torn down yet, pay close attention to where seals may have leaked, when you do. Lots of clues get washed away in the cleaning fluids.
Wear out your digital camera on the teardown; you'll love yourself for it when you start reassembling. Take notes.
Go slow, rehearse everything, think it thru before doing it, and watch for the seals that stick to the bottom of the irons, then fall off when you carry it to the workbench.
Save your old hard parts - - you never know which one you won't be able to get, next time.
http://foxed.ca/rx7manual/manuals/ho...20your%20rx-7/
I lucked into a paper copy of it (this was pre-web days, people!) after it had gone out of print, and it probably has more grease and margin notes in it than my paper copy of the FSM does.
Prepare to cuss the center iron while trying to settle it... the heat helps it go on, I think.
Know that the "eccentric shaft free end play" must be FREE play; no prying or pressure, it should just slide for those critical couple thousandths of an inch. The pictures of this procedure can be misleading, and getting this adjustment right is the key to longevity in your build. Not knowing this cost me a rebuild and some expensive parts.
If you haven't torn down yet, pay close attention to where seals may have leaked, when you do. Lots of clues get washed away in the cleaning fluids.
Wear out your digital camera on the teardown; you'll love yourself for it when you start reassembling. Take notes.
Go slow, rehearse everything, think it thru before doing it, and watch for the seals that stick to the bottom of the irons, then fall off when you carry it to the workbench.
Save your old hard parts - - you never know which one you won't be able to get, next time.
07-24-08, 04:54 PM
#14
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,604 Likes
on
1,847 Posts
I noticed reading through the FSM that they mention to use engine oil to coat surfaces and such during assembly. When I build my piston engines, I usually dont use engine oil, and instead use engine assembly lube since it "sticks" to things a little better and doesnt "run out" of places. Is it ok to use this stuff in there instead on the bearings, seals, etc that call for engine oil so they will "stick" in place? I really dont see why not, but thought I would ask. I plan to still use oil to coat the housings and plates of course.
Also, I noticed that they talk about using petroleum jelly to hold seals in place on the rotors. Im sure that if I can use the assembly lube, I can accomplish this as well without the jelly. Good idea? I plan to still use the Jelly for the coolant seals and what not since I dont want that assembly lube floating around in the cooling system however, is that how its typically done?
Im sure I will have a few other questions, but these are all I can think of for now. Any input you have would be nice! Feel free to throw out tips or whatever as well. Thanks in advance!
~T.J.
Also, I noticed that they talk about using petroleum jelly to hold seals in place on the rotors. Im sure that if I can use the assembly lube, I can accomplish this as well without the jelly. Good idea? I plan to still use the Jelly for the coolant seals and what not since I dont want that assembly lube floating around in the cooling system however, is that how its typically done?
Im sure I will have a few other questions, but these are all I can think of for now. Any input you have would be nice! Feel free to throw out tips or whatever as well. Thanks in advance!
~T.J.
the petroleum jelly is used because the seals have springs under them, and the jelly holds it in place, it doesnt swell iron seals, and you really dont need more than a dab anyways
07-24-08, 05:05 PM
#15
OBEY YOUR MAZDA
On N/A engines I keep the sideseal to cornerseal clearence as tight as possible.
Press Mod your rear oil regulator and shim the front. Remember to put the regulator on the iron BEFORE assembly
DLIDFIS
Press Mod your rear oil regulator and shim the front. Remember to put the regulator on the iron BEFORE assembly
DLIDFIS
07-24-08, 08:15 PM
#18
The one thing I don't think is obvious that can cause you a whole lot of grief is the thrust bearings in the front. When you build up the front part of the motor, it should have the front of the motor up. You will install an inner thrust bearing and spacer ring, reaction plate, upper thrust bearing, front cover, etc., then you will install the front pulley and torque it. At no time during this operation can you tilt the engine or you will risk having the thrust bearings migrate out of place. It won't be obvious unless you check the thrust of the e-shaft. (If this happens, there won't be any) By then you've ruined a few expensive parts.
07-24-08, 09:20 PM
#20
One other thing. Make sure before you start that you will have enough uninterupted time to finish the assembly. What ever you do, DO NOT stop part way through, then come back later and finish. When you are torqueing the tension bolts, you can stop. Even taking your time, you can assemble the block in less than an hour.
07-24-08, 10:47 PM
#21
Oh, wait; you're talking about the cavities on the rotors; sorry, I misunderstood "bathtubs."
Last edited by DivinDriver; 07-24-08 at 10:53 PM.
07-25-08, 06:57 AM
#23
Full Member
Join Date: Apr 2008
Location: Cincinnati, ohio
Posts: 169
Likes: 0
Received 0 Likes
on
0 Posts
07-25-08, 07:20 AM
#24
Eats, Sleeps, Dreams Rotary
Join Date: Jul 2004
Location: Allentown, PA - Paterson, NJ
Posts: 3,247
Likes: 0
Received 2 Likes
on
2 Posts
The one thing I don't think is obvious that can cause you a whole lot of grief is the thrust bearings in the front. When you build up the front part of the motor, it should have the front of the motor up. You will install an inner thrust bearing and spacer ring, reaction plate, upper thrust bearing, front cover, etc., then you will install the front pulley and torque it. At no time during this operation can you tilt the engine or you will risk having the thrust bearings migrate out of place. It won't be obvious unless you check the thrust of the e-shaft. (If this happens, there won't be any) By then you've ruined a few expensive parts.
07-25-08, 08:56 AM
#25
Registered shy guy
iTrader: (1)
Join Date: Jul 2007
Location: tewksbury, ma
Posts: 1,436
Likes: 0
Received 0 Likes
on
0 Posts
can some one post a list of any special tools needed to rebuild a motor.
i know its a silly question but i figured there mit ebe some odd ball tools needed to do this.
i know its a silly question but i figured there mit ebe some odd ball tools needed to do this.