I've been eyeing it up for a while now, so its not like there is *no* interest in it...

OOT, sorry to hear about your car man, shes a beauty, you'll get it going again soon though good luck!

 

ok well since i do use this car for daily driver purposes i need to get this thing up and running soon. I have found a replacement 12A from an 84. I am gonna rebuild my blown motor on my own time because right now just swapping engines is the least expensive route at the moment. Anyways what i need to know is that my FB is an 82 12A and this "new" 12A im getting is from an 84. I know all 12A's from 81-85 are inherently the same but are there any differences that i should look at before i start the quick swap? I know i have a front mount oil cooler...this "new" engine i am getting has a bee hive. Anything gonna be a pain in the *** to do swap wise? What should i look out for? thanks for any help in advance?

 

to swap to the fmoc, all you need to do is remove the beehive from the new engine and remove the oil filter pedestal from your current engine and swap it in place of the beehive. the 84 12A is going to have a metal hard line in between the two fittings where the oil cooler lines will need to go for the fmoc. remove the metal line and use your current oil cooler lines and banjo bolt.

 

i almost forgot..you'll need to keep the 84 12A's flywheel in place and you will need a replacement clutch kit, pilot bearing and seal to accomidate the new engine. the 82 and 84 flywheels are weighted differently and mixing and matching flywheels will ruin your engine.

 

sorry to hear about that ... i know that feeling.

 

Damn really..i did not know this....isn't the pilot bearing a bitch to replace? or is that something else im thinking of?

 

oh one more thing the replacement clutch you said i need to get im assuming to get one for an 84. I didn't think they were differences in the clutch kit for 81-85??

 

the pilot bearing is easy to remove if you have the oem tool. best tool investment i've made in years..

the clutches are different. clutch years range from 79-82 and 83-85. the differences are mainly in the step of the flywheel and the spacing of the guide pins

 

so if i have an 84 12A mounting on to an 82 transmission....should i get a clutch kit for an 84 or an 82?

 

Match the clutch to the flywheel/engine. Tranny will bolt up to any 12A/13B.

 

get the clutch kit for the 84 and as trochoid said, the trans will bolt up with no issues.

 

hey OOT, I can't remember exactly what your setup was, but the rats nest and carb's are slightly different as well, if I were you I'd use the 84 block and pretty much everything else from your original engine. I agree with Dave, the Mazda pilot bearing puller was a great investment. And just to second (or third? lol) what they said use the 84 clutch and you will be good to go. Other than that is just "assembly is the reverse of disassembly" haah good luck.

 

sweet ****! thank you guys for the advice and help! woot!

 

Sorry to hear about that onlyonthurs. Get her up running soon, we can't lose a formula white fb

 

Got a used 12a into my Fb last month so she is up and running again (thanks to my damn good friend Chad). So i have been running her a little over a month now. She starts great and runs great.....but i did notice one thing last night on the way home from work. I felt her miss a little bit at about 60-70 mph when i was getting on her (wot). Reminded me of the previous 12A right before she blew. Now after i felt that missing I did not go WOT anymore...i just drove her calmly. My question is this. Do you think I may be running lean? I adjusted the timing on this engine and the timing is spot on. What should i check. Could it be my fuel pump or even my nikki not adjusted properly? I would love to get a hold of a wideband so i can check the A/F levels on this engine but cash flow is not great right now. I am not gonna be getting on her anytime soon ......I will do a once over on the engine this weekend and make sure everything is connected properly. Again only happened at WoT (bettween 60-70) ...at cruising speeds i did not feel it. Then again i may be paranoid . last thing I need is another engine to go bye bye. any suggestions on what else i should check would greatly be appreciated


edit: i will check my plugs this weekend and snap a pic of them and post them here. Maybe that may tell me something as well

 

Time for a new fuel filter? Very cheap insurance.

 

I was searching the forum and found this thread....I hope it is okay to revive it since I have the same problem and a need for the same solution. Like the original post stated, I was driving home from work at about 60mph highway speed and without warning there was a slight jolt and power went to almost nothing. Limped about 15 miles home only because I was on an interstate and didn't have to stop.

I guess I'm looking for a replacement 12a engine or other workable suggestion...

 

Oh my god, he has 15 posts and found a relevant thread from over year ago.

Hey guys, over here! This one searched!

Well done.

Seriously, though, the first step is to pull your upper two spark plugs, one at a time, and listen for a consistent noise from both. If you really did drop a rotor, this is a good way to start. We all fear the dreaded blown engine, but go ahead and diagnose it before you call it quits. We'll help you figure out what you're looking at, and you're already off to a good start.

 

Crit,

Thanks for answering. I was told I need to make sure the distributor is 100% disconnected before trying this. So, pull one of the top plugs and turn the engine...listen....repeat for the second plug after reinstalling the first. Sounds should be the same....correct?

By the way....finding the search took a bit of effort....

 

If you've got an 81-up car, just pull the connectors off the ignitors, which are two little black plastic parts attached to the front and side of your distributor. They actually fire the coils. You could alternately unscrew the 8mm nuts that power and ground the coils, or pull the high-voltage lines off the coils. Any time I disconnect the coil/plug wires for troubleshooting, I ALWAYS manage to get shocked somehow, so I'd just pull the ignitor plugs off.

You can then unplug each upper spark plug, one at a time, ask a buddy to hit the starter for you, and listen to the pulses you get from the hole (the upper plug holes, where they penetrate into the engine, are really much smaller than the threads of the plug, so you can hear air rushing through the tiny hole). Replace the spark plug and check the other rotor. If you have lost a rotor, they'll sound very, very different. Give it a try and tell us what you find.