Working on carbon locked motor - motor pulled
 

I have a carbon locked gslse and the motor has been pulled. Should it be reinstalled to work on or would it being out of the car make it easier?

I've seen this thread for what I need to do so I'm just thinking if it would be easier one way or the other.
https://www.rx7club.com/1st-gen-arch...7/#post2385473

Thanks

usually its best to loosen it by spinning it backwards. it is easy to do this, either with the factory tool, or a prybar through the round hole in the bellhousing. out of the car, you might use the 54mm e shaft nut?

How do you know its carbon? It could be a chipped seal. If you try to spin it you could do more damage internally. Its best to just break it down and rebuild it.

My plan is to take it slow and not force anything. Soaking with MMMO and trying to turn by hand (not forcing). Also I'll inspect the what I can through the intake/exhaust ports as well as the spark plug holes.

I'm not in a hurry, I just want to get it right and not cause further damage. If I can save it without a rebuild, I'd be OK with that.

turn it backwards. if it is carbon lock, it wants to go backwards. if its something else it doesn't matter

Exactly!

OK I'll try the reversing. I was able to go see the car this weekend and found out the story of how it became seized. He was out of town for a month and came back to start it. It started and ran normally and let it idle for a while. He turned it off and went back inside and the next day it wouldn't start.

he tried to push start and it still was locked, but like you are saying trying in reverse would have been a better idea. The motor looked pretty dirty on the intake manifold so I'm hoping a good cleaning will do the trick. I'm picking it up on the 28th so I'll post some updates once I get it home. Thanks for the help.

! i hate the 21st century, when i was a kid. we called the guy, and we'd go look at the car that day, and pick it up that day. this 10 wait, is just annoying!

if i bought it, i'd pour a bunch of lube* down the carb, wait a bit, and then use a pry bar to spin the engine backwards. when it pops free, spin it over a few time, start it, and beat the snot out of it for a while, and it should be fine.


*MMO isn't a mystery, we have the MSDS, its not really a lubricant. you might as well mix a little motor oil with a little gas

I am friends with the guy who is selling it so he's been very gracious to let me wait to pick it up till I had time. Needed to get my ducks in a row before I could pick it up. It's also been for sale for over 6 months so I think he's happy to see it sold

Update: i am picking up the car this Sunday (22nd) so I will be able to get the process started a week earlier than I thought!

I got the car home and pulled the exhaust manifold off. The front rotor looked fairly clean. The rear rotor was caked in carbon and oil so I think it might have a bad oil seal?

Would anyone suggest using diesel to soak the internals or would the MMMO be a better suit in this situation?

Here is the best picture I could get of inside the housing:

Soak that in MMO or WD-40. Most likely the rear oil control rings are hosed.

I would get a can of GUNK engine decreaser The stuff you detail your engine with. I use it to clean rotors when I rebuild. Works great. Spray liberally and let soak for a day periodically recoating and spinning the engine over. Then rinse with carb cleaner. Massage the seals with your finger. You can stick a tooth brush in there to clean as well.

I am torn now because should I still attempt to get the motor running knowing the oil seal is likely bad or just save the effort and just start the process of rebuilding it.

I would just rebuild it. It can be done for $500 and youll know its all new inside. Youll have to clean it either way.

When you say for $500 - what all do you mean? Apex seals alone are $350 without shipping from Goopy. Just curious for my own build.

get it running now, thats the fun part. if it needs a rebuild it needs a rebuild...

I use Atkins seals. $200. The cheapest basic seal kit,new apex springs, corner plugs,fd corner springs,viton o rings. I went crazy and bought new control ring springs on this last one... so $500-600 roughly.

Yeah if I am going to have it all apart, I will replace all of the seals. I'd rather do it right than cheap.

Out of curiosity - how many miles are on that engine? My 13b (-SE) made it to 222k miles and it's out of the car right now being replaced with a lower miles uncracked engine, plus Exedy Stage 1 clutch and a RB aluminum flywheel.

My rear rotor on the original engine looked very similar and the white deposits on the surfaces of the exhaust manifold could also indicate coolant being burned. Did you pull the plugs - and what did they look like? That could tell you something about which rotor is to blame, but either way - a rebuild is in your future,

No the plugs were already pulled when I got the car. It has 177k and it is the original motor. I bought it from the 2nd owner. With the rebuild comes major overhaul of pretty much everything.

Well I snapped two breaker bars trying to get the flywheel nut off. Might have to take it down to the local tire shop to try to get it loose. Any suggestions before I get down there? It was suggested I used heat to help free it up. Two 1/2" drive breaker bars down and Id rather not buy a 3/4" just for this.

https://farm9.staticflickr.com/8642/...a47ed54a_c.jpg20150301_162707 by tallbozo, on Flickr
https://farm9.staticflickr.com/8602/...41373ab0_c.jpg20150301_163930 by tallbozo, on Flickr

An impact works wonders. Or you could use a chisel. I had to use one once. It worked but I didn't like the cuts it makes in the nut. Ever since then the impact is what I use.

I have an electric (Corded) Impact gun that's available to me but its only 350 ft/lbs max. Would that do the trick?

Should work - the torque spec from FSM is from 268ft/lbs - 340ft/bls, and I used the Racing Beat tool designed for the job to remove the stock flywheel nut and install the new lite flywheel. I was somewhat surprised that the removal force wasn't too bad with my full weight on the 3' arm, but that equates to 170lbsx3ft = 510ft/lbs of available torque.

Once you get the right tool, it will go quickly. Also, the hammer effect tends to magnify torque using the mass of the object against it - on that note, you are using some kind of flywheel stopper, right?

I didn't go back through the entire thread, but make sure the front eccentric bolt is loosened before removing the flywheel. This won't help with flywheel removal, but that front bolt can be hard to remove without using the flywheel as a stop.

Yes the front bolt is off already Thankfully. I have a chain bolted to one of the clutch/pressure plate bolts. I was surprised we broke both breaker bars.

Heat the rear nut with a MAPP torch then give er hell. I got the 3/4" breaker bar, never snapped that one but went thru some 1/2"ers. Slide a pipe over the breaker bar for more leverage. I've been impressed and horrified with the threadlocker some builders use.

Go to tractor supply and buy a 3/4" breaker bar. $30 well spent.

If you use the rear iron as an anchor point to hold the flywheel, make sure to use a couple places. I've broken a rear iron by using only one bolt.

Thanks for the advice. I've picked up a 3/4" drive impact gun so that should help. We will heat it up and give it a go. And thanks for the suggestion to add multiple anchor points on the chain.

What you might try is heat it up and then freeze it immediately with an upside down can of air duster. Try that a few times then it should come right off. Its a must if anyone has ever lock tighted the flywheel.

Same issue. Had the motor on a bench and no where to clamp it. Map torch to the nut then rapid cooled it with a hand full of ice. Did this about 3 times and it broke loose with a regular breaker bar.

The only 54mm nut that was ever hard to remove was on an Atkins engine where someone had used like a whole tube of blue loctite. I had to buzz it with the impact for the entire time it was turning just to take it off the end of the shaft. I'd never seen such a stupid inappropriate use of a product before. The engine was also over-ported and had blue loctite everywhere! They even used it on the alt pulley nut and waterpump pulley. Who does that!?!

Did Atkins actually build this thing? Someone else could have. It was built with Atkins parts. That's all I know.

I'm not sure if it's been rebuilt. I was under the impression it was the original motor but couldn't tell if it had been rebuilt. How can you tell it has atkins parts?

Jeff has rebuilt a ton of engines, he can tell lol

I wasn't questioning his knowledge...I am wondering what gives it away.

there are many details that can tell you if an engine has been rebuilt. the better the rebuild the harder it can be to tell anything was done, as these details will be correct.

i think the first easy sign, is just an even covering of dirt/grease. a rebuilt engine will be clean(er).

the second thing to look for is signs that things were painted, a post 78 engine from Mazda has iron colored irons, and the housings are bare aluminum, the only thing that gets painted are the oil pan, and water pump housings. all the bolts are a gold zinc plating. if you see black irons, its either an old engine, or someone was in there.

sealer. Mazda used a grey sealant, on the oil pan only, and their application is very tidy. a big tip off an engine has been rebuilt is sealant between the "legs" of the housings.

incorrect parts. there are a LOT of engines that get built with a set of unmatched housings. especially the 12A's as there are a variety of different ones that are "the same"

other things to look for are on the periphery, like the wrong hose clamps, painted transmissions, twisted clutch hoses, etc etc

Here are some pictures when I took the intake manifold off. Lots of actual dirt and build up. The intake gasket is a pain to remove too. Razor blade scraping.

i think that is the original engine, its got a nice even coating of gunk, all the fasteners are correct, intake gasket is mummified...

Agreed. That is an original engine. Enjoy the teardown on a masterpiece of mass produced rotary goodness. Not a bastard with mismatched parts, too much loctite or too much porting. The way you find everything inside is as it should be with no RTV on the front counterweight lol.

This setup worked well for me.
https://www.rx7club.com/attachment.p...1&d=1425447193

Just picked up a 3/4" drive impact gun so that should do the trick. I'll need to borrow my neighbor's air compressor but should be easy enough once I get it warmed up and use the air gun. Sheeeesh....I just need one bolt off to see if I need to start looking for new housings and/or rotors!

Id be more worried about the condition of the housings then the rotors. SE housings are usually good with minimal flake and are still available new, but expensive either way. Rotors are cheap.

Finally got the Flywheel nut off. The air gun did the trick and was silly we didn't get it sooner. I was able to get the whole engine disassembled and everything was in better shape than I was expecting. The housings seem to be in good shape and I will get some better pictures once I get them cleaned.

Any advise for soaking them in degreaser and how long? I bought a Cement mixing tub (24"x36") so I can lay most of the housings and rotors down to soak. I will get getting bulk cleaning done hopefully this afternoon so I can get some better pictures of the housings and rotors.

Thanks

https://farm9.staticflickr.com/8606/...c7499ea2_c.jpg20150307_113336 by tallbozo, on Flickr
https://farm9.staticflickr.com/8564/...efa63a03_c.jpg20150307_114352 by tallbozo, on Flickr
https://farm8.staticflickr.com/7593/...c3380a72_c.jpg20150307_131057 by tallbozo, on Flickr

Rear Housing:
https://farm9.staticflickr.com/8671/...18732271_c.jpg20150307_131640 by tallbozo, on Flickr

Carbon Lock:
https://farm8.staticflickr.com/7286/...8ef9c89b_c.jpg20150307_132051 by tallbozo, on Flickr

Center Plate surface:
https://farm8.staticflickr.com/7608/...06895ee0_c.jpg20150307_135306 by tallbozo, on Flickr

https://farm8.staticflickr.com/7589/...37ab2e9e_c.jpg20150307_151107_1 by tallbozo, on Flickr

http://contentinfo.autozone.com/znet...o/EB1/image/3/

This is the best stuff Ive found so far for soaking. Soak each part for 10 minutes then scrape with a razor blade and rinse with brake cleaner. Soak again for 10 minutes and scrub with a nylon brush and tooth brush plus a tiny dental type scraper for the seal grooves being careful not to score them Rinse with brake cleaner again and spray with WD40 to prevent rust.

I suppose after the second GUNK soak you could fill your tub with as straight as possible Super Clean or Purple Power for a 30 minutes soak then rinse again with brake cleaner.

Alright....I got the housings and rotors cleaned fairly well. I tried to get some pictures so I can get some advise about the condition and if they are reusable.

One of the housings has some slight marring. Not flaking but its a rough edge for about an inch.
https://farm8.staticflickr.com/7610/...8d0f02cd_c.jpgDSC_0997 by tallbozo, on Flickr
https://farm9.staticflickr.com/8703/...eb214906_c.jpgDSC_1009 by tallbozo, on Flickr

Also one of the rotors on the apex seal channel has a couple nicks, that I wanted to get your opinions on...
https://farm9.staticflickr.com/8661/...7c55357d_c.jpgDSC_1002 by tallbozo, on Flickr

Other than those two items, I think they are in really good shape. No scratches or groves on the housings and the rotors cleaned up nice.
https://farm8.staticflickr.com/7627/...634c056d_c.jpgDSC_0995 by tallbozo, on Flickr
https://farm9.staticflickr.com/8574/...05a9ff2b_c.jpgDSC_0988 by tallbozo, on Flickr
https://farm8.staticflickr.com/7626/...8315ae38_c.jpgDSC_0976 by tallbozo, on Flickr

https://farm9.staticflickr.com/8679/...501d5c9f_c.jpgDSC_1000 by tallbozo, on Flickrhttps://farm8.staticflickr.com/7287/...38f6cc03_c.jpgDSC_1001 by tallbozo, on Flickr
https://farm8.staticflickr.com/7285/...f22bc2ce_c.jpgDSC_1004 by tallbozo, on Flickr

Worked on the intermediate plate tonight and made some progress. Enough i guess to get some pictures up on here so you can see the surface anyways. I am curious, how hard can I scrub the chrome surface and what should I use? I have a nylon scrub brush and have been keeping the brass brush away.

Here are a couple pictures. I edited them slightly so you can see the surface better. Nice and smooth but some discoloring. No flaking.

https://farm9.staticflickr.com/8689/...bba13d5e_c.jpg20150309_202020_1 by tallbozo, on Flickr
https://farm8.staticflickr.com/7598/...45502849_c.jpg20150309_202040_1 by tallbozo, on Flickr

The irons aren't "chromed". They are nitrided which is a surface hardening treatment, and from what I can see in the pics, is in very good shape.

It's pretty hard but can be damaged and ruined when idiots send their irons out to be lapped or resurfaced. DON'T do that. Instead, take a razor blade and carefully "shave" off the residue from the coolant seals and any other high areas of buildup from carbon and old coolant. That's all I ever do on my irons, and it keeps the nitriding from getting damaged.

You will notice some slightly weaker areas where the coolant seals sit. Don't try to dig out the weak material because it can lead to coolant leaks in the future. Just shave them flat with a razor blade using the adjacent surface as a support guide. Does that make sense?

Then in the end, I like to use compressed air to clean out the loose iron dust. It might be possible to use a nylon brush, or even a brass brush (if you're super careful) to clean these areas after the shaving process, but I prefer compressed air.

Yes that makes perfect sense. I'm just want to make sure I don't ruin good parts by using the wrong cleaning tools.