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Nice job getting the bolt off. That front pulley/hub bolt needs to be the first one taken off. I had to also learn this lesson the hard way.
haha luckily my pops has that HUGE pipe wrench. And it made it nice to have the rear iron off for the room to fit the wrench on the flywheel hub. And what's the procedure for removing any high spots on the chrome of the housings and irons? "0000" steel wool?
So a few thoughts on inspecting.... I go premix and just ordered the block off plate. (Just had the oil lines looped before) so can I remove the omp gear and shaft with the block off plate installed to seal or does that gear and shaft need to still be in place? And what's with the exhaust port sleeves? What does that hole in the bottom do and what are the options for better flow without that hunk of metal?
Last edited by risingsunroof82; 03-21-21 at 08:03 PM.
At the high risk of being annoying here i have yet another worry about the wear in the pics..... too much? and what to do if so? Budget doesn't have room for sending out to be resurfaced and id hate to not be able to use these street port irons and housing....
So a few thoughts on inspecting.... I go premix and just ordered the block off plate. (Just had the oil lines looped before) so can I remove the omp gear and shaft with the block off plate installed to seal or does that gear and shaft need to still be in place? And what's with the exhaust port sleeves? What does that hole in the bottom do and what are the options for better flow without that hunk of metal?
no, the OMP shaft helps meter the oil flow, if you remove it all the oil goes in the front cover and it trashes the bearings.
best flow is to leave them alone, the holes are for air pump air.
so I got my atkins kit today! But here's more questions.
1. Are these seals for a stock intake and exhaust setup?
2. I had a orange rear main seal in the engine and this kit comes with the brown.... the orange is thicker but same inside and outside so is this still usable?
3. What are the thoughts on these gasket compounds? Yes, no.... or other? Thanks!
1. The aluminum exhaust gasket will work in several places on the stock exhaust or a Racing Beat single-pipe kit. The larger paper gasket is for the Air Control Valve on the stock manifold. Could be used for a block-off plate if you removed your ACV. Don't remember what the two smaller paper gaskets are for but it's the stock manifold. None of those papers are needed on an aftermarket intake.
Good to hear and thanks guys! I'm working on spec-ing the side seals now. I was surprised to not see the oil pedestal gasket or top rad neck seal.... but I guess those aren't part of the actual rebuild so makes sense.... won't be a problem tho.
oil filter pedestal uses O-rings for sealing the mating surfaces so no gasket required. and if i need the gasket for the upper rad nose neck, i just make one from gasket material.
since the new rear main seal is more shallow is it tolerable to just be flush with the rear iron? If it needs to be fully pressed in what suggestions you got without hurting the seal?
Last edited by risingsunroof82; 03-29-21 at 06:49 PM.
here it is buttoned up! The front rotor seems to have a bit more oomph when rolled over than the rear but that seems likely due to the Vaseline being packed all thru the rotors right?
I have this flywheel from my first 82 rx7 and see it's only a 23 pound flywheel. Is there much worry on 12a balance if your only swapping between other 12a flywheels?
79-82 is balanced differently than 83-85. The flywheels and the counterweight (if it was an auto) are weighted differently by year range. The weight/balance has to match the front counterweight and rotating assembly.
What you could do is look for an 83-85 12a counterweight and get a lightweight steel flywheel. I'd suggest finding the counterweight first, as they're nla from Mazda.
Edit - just saw Mazdatrix is making them for $267. Might look for a used one from somebody here, or find a junkyard parting an auto FB and get one cheap.
Crap.... I already bolted the front housing down but I have a Pic with the counter weight but can't remember what was stamped on it but I think it was s2 maybe?
So I'm just trying to make sure I don't shake my new engine apart so here what info i have on rotors, balance weight and flywheel. My rear rotor has the R and N stamped. The front only has the F. Are these different weights? The N I've collected means non turbo i guess? But why did the front only have the F? And I see a lot of confusion with using the term counter weight and balance weight. To clarify this is a manual transmission so since the flywheel accounts for the rear counter I'm only referring to the properly referenced balance weight. Right? Lol thanks for all your patience and knowledge!
I don't know about the "N" on your one rotor, but I do think F&R refer to front and rear.
All rotary engines have a front counterweight and either A) one-piece iron flywheel, balanced to match the front weight or B) a counterweight similar to the front, with an unweighted flex plate bolted to it.
A) is what they put in manuals and B) goes with autos. As you probably know, to run a lightweight flywheel (like RacingBeat and MazdaTrix sell) you need to get an auto's counterweight from the same year range (because the aftermarket flywheels themselves are not balanced).
The front and rear weights are matched (balanced) by year ranges. You aren't supposed to mix-match different year ranges due to imbalance reasons.
Will your motor come undone? I don't know, I don't have that much experience.
Would I risk it, knowing that Mazda, Mazdatrix and RacingBeat all say not to do it? No, I would not put a known imbalanced high rpm motor in my car.
I don't know about the "N" on your one rotor, but I do think F&R refer to front and rear.
All rotary engines have a front counterweight and either A) one-piece iron flywheel, balanced to match the front weight or B) a counterweight similar to the front, with an unweighted flex plate bolted to it.
A) is what they put in manuals and B) goes with autos. As you probably know, to run a lightweight flywheel (like RacingBeat and MazdaTrix sell) you need to get an auto's counterweight from the same year range (because the aftermarket flywheels themselves are not balanced).
The front and rear weights are matched (balanced) by year ranges. You aren't supposed to mix-match different year ranges due to imbalance reasons.
Will your motor come undone? I don't know, I don't have that much experience.
Would I risk it, knowing that Mazda, Mazdatrix and RacingBeat all say not to do it? No, I would not put a known imbalanced high rpm motor in my car.
I have other flywheels on hand (not in my garage but near by) so that's not an issue if this flywheel won't work.... but I have some pics of the rebuilt engine with everything that came in it eg.... rotors, housings, irons and front balance weight. It looks like the engine is a 79-80 if I'm correct.
So I'm just trying to make sure I don't shake my new engine apart so here what info i have on rotors, balance weight and flywheel. My rear rotor has the R and N stamped. The front only has the F. Are these different weights? The N I've collected means non turbo i guess? But why did the front only have the F? And I see a lot of confusion with using the term counter weight and balance weight. To clarify this is a manual transmission so since the flywheel accounts for the rear counter I'm only referring to the properly referenced balance weight. Right? Lol thanks for all your patience and knowledge!
the F or R stamp only means it is a 76-82 rotor, and the NF is 83-85 non turbo. different weights. the 12A turbo it TF and TR
So I have to reopen the engine..... uughhh. That's what i get for assuming the previous builder of this engine used all the same parts. But here's my thought... since the rear rotor seems to be the odd one out (rest of engine is either 79 or 80 from what I see) I can leave the front rotor alone and just swap the rear with a stamped R only rotor. I have a few donor engines I'll Crack open and find a good replacement. can I get away with just unbolting the tension bolts and rear intake bolt to the rear iron? Using the intake to hold the rear housing to the rest of the engine to keep from messing up the coolant seals? And I don't see why i can't leave the rear main seal in the iron either right? I'm just really frustrated but now is the time to do it and this is probably why their rebuild didn't last long.
One more update.... pulled the rear iron off, removed the rotor and went to my dad's shop where the spare engines are. Found the right gen of rotor but this engine has say for about 25 years. Toasted. Rotor tips were rotted and gone. But I have my old 82 engine I still gotta pull apart which by looking thru the exhaust ports shows good signs and clean rotors. Just gotta get it apart this weekend. Since I didn't mess with my rebuilds front stack, just the rear iron I shouldn't have thrust bearing issues right? Sorry for all the stupid and noob questions but I'm learning a lot to say the least.... including patience. Lol
03-20-21, 07:09 PM
