79 RX-7 12A gaskets sets?
04-11-09, 10:32 AM
#1
79 RX-7 12A gaskets sets?
Hey guys,
Well it seems I may have a problem with my 78 production 79 RX-7. It is basically all original,and only has around 85k miles on it. While out using it last week I noticed a large cloud of blue smoke while shifting it at redline between 1st,and second,and also 2nd to third. I then stopped ,and revved the engine up,and had large clouds of blue smoke emminating from the tail pipe. I am pretty sure the oil seals have probably let go on atleast one rotor. I have never rebuilt ,and engine,but I may try it,or have a local guy I know do it for me.
My question though is where can you get seal kits for the 79-80 engines? Mazdatrix says they are no longer available. Do you guys think I could get away with just new seals in the engine,and not needing apex seals with such low mileage(but old age),and an engine that runs so good,and strong otherwise? I would like to rebuild this engine because the car is so original,and an early model. I know it wouldn't matter to most,but I would like to keep it factory original. I have a spare 79 12A from a parts car in the garage,but I don't really know its history. I also have a 85 12A that was in my 83 RX-7 years ago that ran great,but has 150kish miles on it,but ran great.
What is the minimum I am looking at to rebuild this stock factory 78 production 12A if it doesn't need hard parts like apex seals,and such. Where can I get the parts?
Thanks,
Chris
78 RX-7 GS
74 REPU
78 Datsun 510 coupe
Well it seems I may have a problem with my 78 production 79 RX-7. It is basically all original,and only has around 85k miles on it. While out using it last week I noticed a large cloud of blue smoke while shifting it at redline between 1st,and second,and also 2nd to third. I then stopped ,and revved the engine up,and had large clouds of blue smoke emminating from the tail pipe. I am pretty sure the oil seals have probably let go on atleast one rotor. I have never rebuilt ,and engine,but I may try it,or have a local guy I know do it for me.
My question though is where can you get seal kits for the 79-80 engines? Mazdatrix says they are no longer available. Do you guys think I could get away with just new seals in the engine,and not needing apex seals with such low mileage(but old age),and an engine that runs so good,and strong otherwise? I would like to rebuild this engine because the car is so original,and an early model. I know it wouldn't matter to most,but I would like to keep it factory original. I have a spare 79 12A from a parts car in the garage,but I don't really know its history. I also have a 85 12A that was in my 83 RX-7 years ago that ran great,but has 150kish miles on it,but ran great.
What is the minimum I am looking at to rebuild this stock factory 78 production 12A if it doesn't need hard parts like apex seals,and such. Where can I get the parts?
Thanks,
Chris
78 RX-7 GS
74 REPU
78 Datsun 510 coupe
04-12-09, 04:04 AM
#2
Ah feel yor pain Chris - my SA #2 is in the same boat.
I am using the FB OEM kit for rebuild - all gasket specs are the same EXCEPT the exhaust and intake mani's - which are easily available. I have seen these kits on ebay lately for $125-140 for the complete _gasket_ kit, which does not include apex seals, oil control ring seals or seal _springs_. (kit on ebay right now)
Some thoughts:
-since you will be disassembling the engine anyway, hold off on the apex seals and measure the thickness of yours against NOS ones - the Shop Manual should state the minimum thickness you can reuse
-the deal breaker on the motor will be the condition of the rotor housings. There will be flaking, usually along the edges; worse there may be shatter marks. Pulling me 12a apart revealed one of the housings had terminal flaking. I was lucky to find a new replacement housing. These are unobtainium for SA, and likely FB too... NOTE: the SA 12a housings are NOT interchangeable fr to back, each is unique (the bastids) - and NOT interchange with FB (unless you got the whole FB version route).
-check out Pineappleracing.com's site. They have some great better-than-OEM water-jacket O-rings that are much more durable than the stock ones that come in the kits. Pricey, but a great investment in a keeper SA, IMHO. Plus most of the other bits you may need. And _super_ on the phone tech help. Likewise Dan Atkins really stepped up for me when I needed a replacement center iron.
Pineapple also has a great series of rebuild videos on the site. And Atkins and mazdatrix both sell How 2 Rebuild DVDs. I would have either or both with you for the rebuild (I have a player set up with a little TV right in my shop for this). Worth spending the $25-ish on the DVD just so you can see what your up against if you are thinking of tackling this yourself. Knock-on-wood, it actually looks pretty straight forward! (ask me again after)
-you might want to pull apart the spare SA 12a first, if only just for practice. Might get some decent housings or irons off it too!?
-I think between the gasket kit, DVD, specialty tools (a nifty air-pressure gauge/block Pineapple sells that seals up the newly assembled block at the water pump opening, so you can pretest the seals to make sure there is no leaks before dropping in the car; the 33mm -ish socket needed to pop the rear e-shaft nut on/off; torque wrench) and the separate oil control ring/seal kit (which you will need), I am in it for about $350. This doesn't include housings or irons... and it would be kinda dumb not to be replacing the water pump and new hoses, plus a chem-dunk/pressure test of the rad while your in there. I'd consider having your oil cooler sonic cleaned too. And how 'bout those original and now-brittle oil metering pump lines? Pineapple's do-it-yerself OMP rebuild kit would be smart! So. Where are we? $550-600? Price out a minimum rebuild at mazdatrix, and that isn't looking too shabby. In for a penny, in for a pound...
happy to provide what ever humble ideas I've stumbled across in the _dis-assembly_ section of my project - PM if needed.
Keep us posted
'luck
Stu Aull
80GS
Alaska
I am using the FB OEM kit for rebuild - all gasket specs are the same EXCEPT the exhaust and intake mani's - which are easily available. I have seen these kits on ebay lately for $125-140 for the complete _gasket_ kit, which does not include apex seals, oil control ring seals or seal _springs_. (kit on ebay right now)
Some thoughts:
-since you will be disassembling the engine anyway, hold off on the apex seals and measure the thickness of yours against NOS ones - the Shop Manual should state the minimum thickness you can reuse
-the deal breaker on the motor will be the condition of the rotor housings. There will be flaking, usually along the edges; worse there may be shatter marks. Pulling me 12a apart revealed one of the housings had terminal flaking. I was lucky to find a new replacement housing. These are unobtainium for SA, and likely FB too... NOTE: the SA 12a housings are NOT interchangeable fr to back, each is unique (the bastids) - and NOT interchange with FB (unless you got the whole FB version route).
-check out Pineappleracing.com's site. They have some great better-than-OEM water-jacket O-rings that are much more durable than the stock ones that come in the kits. Pricey, but a great investment in a keeper SA, IMHO. Plus most of the other bits you may need. And _super_ on the phone tech help. Likewise Dan Atkins really stepped up for me when I needed a replacement center iron.
Pineapple also has a great series of rebuild videos on the site. And Atkins and mazdatrix both sell How 2 Rebuild DVDs. I would have either or both with you for the rebuild (I have a player set up with a little TV right in my shop for this). Worth spending the $25-ish on the DVD just so you can see what your up against if you are thinking of tackling this yourself. Knock-on-wood, it actually looks pretty straight forward! (ask me again after)
-you might want to pull apart the spare SA 12a first, if only just for practice. Might get some decent housings or irons off it too!?
-I think between the gasket kit, DVD, specialty tools (a nifty air-pressure gauge/block Pineapple sells that seals up the newly assembled block at the water pump opening, so you can pretest the seals to make sure there is no leaks before dropping in the car; the 33mm -ish socket needed to pop the rear e-shaft nut on/off; torque wrench) and the separate oil control ring/seal kit (which you will need), I am in it for about $350. This doesn't include housings or irons... and it would be kinda dumb not to be replacing the water pump and new hoses, plus a chem-dunk/pressure test of the rad while your in there. I'd consider having your oil cooler sonic cleaned too. And how 'bout those original and now-brittle oil metering pump lines? Pineapple's do-it-yerself OMP rebuild kit would be smart! So. Where are we? $550-600? Price out a minimum rebuild at mazdatrix, and that isn't looking too shabby. In for a penny, in for a pound...
happy to provide what ever humble ideas I've stumbled across in the _dis-assembly_ section of my project - PM if needed.
Keep us posted
'luck
Stu Aull
80GS
Alaska
04-12-09, 07:13 AM
#3
Thanks Stu,
I thought you may reply to this thread,with you being so passionate about the SA as me. Thanks for the info,and I will call both Atkins,and Pineapple this week. I really don't trust myself to do a rebuild because I am afraid I may put something together wrong,and have to do it all again. I am sure there will be some flaking on the rotor housings,and probably chatter marks ,but hopefully not too bad. The engine doesn't have a lot of miles on it,but the age of the seals in the engine has probably caused thsi problem.
I may replace the water pump,but it was new three years ago,and probably only has 6-7000 miles on it so far. The radiator,and hoses were new three years ago as well. I don't think I replaced the oil injection lines however,and I should do those. I think I have a spare SA oil cooler or three,and maybe I will just get one of them cleaned,and remove the stocker.
I am half tempted to pull the stock engine,and drop the spare SA 12A in to run the car this summer,and then look into rebuilding this one. I am confused about the price listing on Atkins website. They have Kit A-B-C,and master kit. The Master kit includes more things than the more expensive Kit C,but is missing some of the more important things that Kit C comes with.
I hope I can save this engine because I would like to keep this one instead of using say an FB engine. I have the nut for removing the eccentric shaft nut already. I have disassembled a few engines before that were terminal,but I wasn't careful about what I was doing,and I am worried I will lose some important part while doing it even for practice let alone while trying to do a rebuild.
Maybe I will but the seal kit from Atkins/Pineapple,and have my friend do the rebuild for me. That way I know it will be done by someone who has done it many times,and knows what they are doing.
Thanks again,and I will be in contact.
Chris
Keeping one more early SA on the road
I thought you may reply to this thread,with you being so passionate about the SA as me. Thanks for the info,and I will call both Atkins,and Pineapple this week. I really don't trust myself to do a rebuild because I am afraid I may put something together wrong,and have to do it all again. I am sure there will be some flaking on the rotor housings,and probably chatter marks ,but hopefully not too bad. The engine doesn't have a lot of miles on it,but the age of the seals in the engine has probably caused thsi problem.
I may replace the water pump,but it was new three years ago,and probably only has 6-7000 miles on it so far. The radiator,and hoses were new three years ago as well. I don't think I replaced the oil injection lines however,and I should do those. I think I have a spare SA oil cooler or three,and maybe I will just get one of them cleaned,and remove the stocker.
I am half tempted to pull the stock engine,and drop the spare SA 12A in to run the car this summer,and then look into rebuilding this one. I am confused about the price listing on Atkins website. They have Kit A-B-C,and master kit. The Master kit includes more things than the more expensive Kit C,but is missing some of the more important things that Kit C comes with.
I hope I can save this engine because I would like to keep this one instead of using say an FB engine. I have the nut for removing the eccentric shaft nut already. I have disassembled a few engines before that were terminal,but I wasn't careful about what I was doing,and I am worried I will lose some important part while doing it even for practice let alone while trying to do a rebuild.
Maybe I will but the seal kit from Atkins/Pineapple,and have my friend do the rebuild for me. That way I know it will be done by someone who has done it many times,and knows what they are doing.
Thanks again,and I will be in contact.
Chris
Keeping one more early SA on the road
04-12-09, 01:37 PM
#4
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if you want to use OEM mazda stuff (and you do!) buy any 12A o-ring set (they usually end in 10-s60), and then buy the intake and exhaust gaskets separately.
if its low mileage and runs well, pull it apart and just start cleaning/measuring, running well = engine looks pretty nice
minimum it should get apex seal springs, corner seal springs, and plugs (do SA's have?), and the reason for the smoking, the rotor seal o rings, and a thermostat
if you want to upgrade, mazda updated the apex seals, corner seals, FD corner seal springs. you can bump the oil pressure but imo a streetcar doesn't need 110psi like the FD, if stock is 71psi bumping to 80-85psi is good
like stu says the real concern is the chrome flaking on the rotor housings, no solution, no new housings...
everything else gets measured, and compared to spec
if its low mileage and runs well, pull it apart and just start cleaning/measuring, running well = engine looks pretty nice
minimum it should get apex seal springs, corner seal springs, and plugs (do SA's have?), and the reason for the smoking, the rotor seal o rings, and a thermostat
if you want to upgrade, mazda updated the apex seals, corner seals, FD corner seal springs. you can bump the oil pressure but imo a streetcar doesn't need 110psi like the FD, if stock is 71psi bumping to 80-85psi is good
like stu says the real concern is the chrome flaking on the rotor housings, no solution, no new housings...
everything else gets measured, and compared to spec
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