Hello! I'm relatively new to the whole wrenching on cars thing, and recently got a '90 Civic Sedan with a B16A swap, in non running condition. I discovered that the bottom end was damaged due to a faulty harmonic balancer, but it doesn't look like the damage was catastrophic, thankfully. I definitely need to replace my main and connecting rod bearings as well as either get my crank+flywheel machined or replaced. My question is, is this all I should worry about doing? I'd like to avoid having to pull the block out and get a bunch of work done to it, as I'm under a very very tight budget and just want to get the motor started.
TLDR,
I'm mainly just looking for a general diagnosis so I can take the most inexpensive route towards getting this bad boy to reliably fire up and go.

My bottom end sans bearings and main caps.

Main caps+ bearings

My harmonic balancer (looks horrible)

The general condition of my main caps

The worst of my main bearings. My con rod bearings don't look great either. None of them look particularly good, but I can't decide if they're fully spun or dangerously close to doing so.

Other side of previous

Where the crank+balancer belongs

My oil pickup. Afaik there was no glitter of death in the oil.

Crank flange damage

Crank itself

 

They honestly don't look that bad, I bet if you just get your crank journals micro polished, knock off high spots with a fine file on the damaged edge on the rear main seal end, replace the pulley, new oem bearings going by letter code stamped on block and crank for the right color of bearings, re shape the dented in oil pickup mouth you'll be fine. You can see where the rear main seal makes contact on the crank so the light filing will clear. I had a old winter beater and while re-ringing the motor, pulled the maincap bridge and the center main bearing was literally burnt black and ovalized. Never spun amazingly.. Just gave it a half fast scotch bright scuffing/polishing to remove the blackness and a light couple taps of a mallet to reround it, slapped it back in and amazing still runs like a champ to this day and that was over 10 years ago. The tangs on the ends of the bearings hold those in there pretty good so if you think have a spun one look for scorring or galling from the tang on the main cap if that would do it, just thinking randomly..
As for your flywheel resurfacing while it's out, unless it has really bad glazing or using a different or new clutch then spend the extra $60 and get that done, if re-using the old clutch and with out bad glazing on the flywheel, put her back together and run it till it slips or dies which would probably be a long time from now depending on how much clutch life is left.

 

Really? That's honestly super encouraging to hear. I had fears of needing to pull the motor and get thousands worth of work done to it. I'll definitely try your advice.
My only concerns are: do I replace the thrust bearings too and does each half of the bearing have to go into a specific journal in a specific orientation, and what do I do in regards to the main or con rod caps if I have a few spun bearings? Can I just throw in new bearings and call it good or should I clean them up first?

 

Everything about putting it back together has all there specific orientation. A certain color bearing is used for each journal using oem to get correct oil clearance. Follow the code given by the numbers and letters you will find on the crank and scribed on the underside of the block- those will give you all the original from factory bearing colors and specific journals as to where it all goes. There is a chart you use that converts the codes to bearing colors required. Google search.. Cleaning up the crank and getting oem bearings and your set. Bearings will only go in one way - cutout groove for tang sides.. You Must plastigage oil clearance for each journal if using non oem bearings. I like to use my Haynes manual all the time for all torque specs and that's been my Bible for over the years.. you can follow all the steps.. it's all easy to do just make sure you have a decent torque wrench.
As for the thrust washers, If they look fine With-Out any signs of glazing, heavy polished sections, heavy signs of wear or scoring then just put the originals back in, check the thrust clearance with crank installed to confirm its still in spec using a feeler gauge and run them or just buy some new ones.
Just look at the condition of all the bearings in comparison to each other and if they look fine and tang sides have no damage then maybe it hadn't spun any. If you had spun any bearings you would probably easily tell..

 

After looking very closely at your pics and what your dealing with, it just looks like a bit of corrosion between the mounting surface from the flywheel to crankshaft and that should be no worries at all. Looking at your all journals and caps, they appear to be in normal condition and the worst of your bearings you pictured sure does not look like it had spun. Just looks like it has seen very dirty oil so that is why I would highly recommend getting the journals micro polished. Other than all that your fine..

 

The damage on the crank flange also appears on the flywheel (minor putting and raised bumps. The damage on both crank+flywheel almost fits together like puzzle pieces) and the worst bearing I showed you has feelable grooves in it. That's the only thing that concerned me, as everything else looks like relatively typical wear for bearings (there is another one on main cap #1with grooves down to the copper but they're substantially less than on #4, the one you saw).I'm not inclined to believe that any are spun as there is no damage other than visual wear on the tang sides of the bearings and caps, and they all seat securely in their places with no play, and there's very little visible marking on the crank journals. I can feel them with my fingernail in places. There's also corrosion/oxidization where the thrust washers should go (at least, I think it's where they should go)
I'm just trying to make sure all my bases are covered so I do this right.

Mating surface. Similar to crank flange damage.

Flywheel surface. No grooves or divots in it.



Better view of the crank. All of the wear you can see I can feel with my fingernail, but barely.

Main #4 bearing

Main #1 bearing

Thrust

 

I definitely think a journal polishing would clean that up to be in fine usable condition and also flush out the cranks oil passages. I would replace all the bearings with correct oem ones, you could plastigauge them if you want after removing the oil pump but I would trust them as being fine to run as the look of your wear is mainly from just the **** that got in your oil. Your one thrust washer looks totally fine and the other is still decent too, I would re-use those. If not done yet, probably should pull the valve cover and clean up those little pools of black oil that hold debris and crud, clean as much as you can while the valve cover is off leaving it spick&span.. Then just clean up the mating surfaces of flywheel to crank. You should be good to go..
I have built a few motors and have never had problems, so any advise I give here is just from personal experience as to what should/will work without issues..

 

Dude I really appreciate your help. I was kind of lost before and super worried I'd have to pull the motor, tear it apart and basically rebuild the whole thing.
With this info in mind, where would you recommend I get my new bearings from? I definitely don't want to skimp on quality with them considering they're critical to the whole thing.
What other things like should I get while this is all apart, like gaskets and assembly stuff like lube, loctite, and gasket maker?

 

I prefer to use only honda bearings but you could get some ACL standard size bearings which are more like all green colored oem bearings that run in the middle of the scale for thickness I think. But you should plastigage those just to be sure.
You may as well replace your flywheel pilot bearing, rear main seal and throw out bearing since it's apart.
I like to use hondabond but you can use rtv sealant mainly for the edges of the 4 cam caps if you replace your valve cover gasket and also you can use a very thin layer of sealant on the oil pick up tube gasket - re-using your old gasket.
Lastly just get a new oil pan gasket.
So in the end your cost of this job should be fairly cheap, the oem bearings will be the most costly but best purchase.

 

Ok. Should I be hyper concerned about clearances? I'd like to get away with just using plastiguage since I don't have the money for mics and bore guages, but I'm also terrified of hearing a dreaded knock on startup or throwing a rod outright. You can tell I'm pretty new to this lol.
Apart from what you've already said, is that basically everything I should worry about? And a random aside, but where would I apply the RTV for the cam caps? I've got a DOHC B16A and I'm pretty sure I have more than 4 cam caps.

 

You put sealant in the bottom corner edges of where the caps meet the surface of the head on the 4 outside cam caps... If you don't, your valve cover gasket is most likely to leak.
Oil clearance is critical so depending on what you use for your bearing either oem or aftermarket, oem ones - just put them in and run it or plastigauge the aftermarket to confirm..
you don't need any thread locker or gasket maker.. Get some engine assembly grease and use that but don't go overkill with it, personally I prefer to use that instead of the oil types..
I really don't think you will have any problems like throwing a rod or having knock... as long as everything is super clean when being put back together you'll be fine. Just use a good torque wrench and torque the caps properly. Pull your spark plugs and disconnect the distributor then crank it over until your oil dash light goes off to build pressure before you go to start it. Simple. Have fun 👍

 

Final question, how would you clean the parts and the top/bottom of the motor so that everything goes smoothly? Aside from that;
Thanks so much for your help! It'll truly prove to be invaluable and will save me a lot of stress. Again, thank you.

 

Where the flywheel bolts tight? That almost looks like some micro welding was happening between flywheel and crank. Those odd and random blue (hot) spots on the flywheel where it touches the crank are odd.

I think that engine has experienced some VERY high revs.

Also replace those hardware store cam cap bolts near the timing gears.

 

Lol I saw those bolts too.. could hit up a wrecker to get some oem ones.. I would kinda question of the bearing cam caps since the poor condition of the rod and mains but that's another can of worms.. Since your not aiming for perfect - But in good running condition, I wouldn't get too indepth as it can get expensive so being on a budget you can get this going fairly cheap.
To clean up the cap surfaces prior to bearing install, I use rubbing alcohol on a non abrasive lint free cloth and scrub hard to remove the burnt on oil or residue then blow them off with compressed air to remove any dust or debris.
The mating surfaces of flywheel to crank you could clean up a bit with a scotch bright pad but don't go crazy with it. Maybe very-very lightly coat those mating surfaces with either oil or rust inhibitor to help prevent any more corrosion. Then just put everything back the exact same way it came apart.

 

Unsure. I bought the car with the crank, balancer, and clutch assembly in the trunk. I didn't get a good look at everything until much later when I dropped the tranny and pulled the oil pan off.
Not the wisest way I should've done things but I love the car too much.

 

Awesome. I'm glad to hear that I can do this stuff right without being horrifically **** about the details and spending money I don't have. Like I said before, I was terrified of turning it over for the first time and having everything go catastrophically wrong.

 

I would have an experienced performance shop look at that crank and flywheel interface. That looks like trouble.

Real street performance has a couple 2jz tear down videos where they talk about the crank to flywheel micro welding. I think Suppy from Hoonigan also trashed a b16 crank on his personal channel with the same micro welding issue. I think he was attempting to spin 11k.

 

Never really looked at the crank pics closely as just mostly the bearings. As what was stated in previous post, getting them inspected at a shop would be a wise idea. The crank might need to be re-machined on the end to clean it up and re-balanced if still usable. The flywheel might not be re-usable with the pitting and those hot spots may have deformed its mating surface throwing it all out of balance. The question about is if those flywheel bolts were tight is a good one..
Might get lucky by getting the crank cleaned up and just getting a good cond. used flywheel.

 

So is my crank junk too? I'm really not too sure what to think. Regardless I'm trying to save as much money as possible and don't want to waste a penny on something that I don't need in order to have a healthy motor.

 

I don't think it's junk, if I were you in your shoes, I would feel confident going out and get a better condition flywheel that has normal wear and a harmonic balancer from the wreckers, use a fine file and clean up the end of the crank of any raised bumps very carefully and then do the bearings.
You should be ok.