Corosion in cylinder

[the sucker king]

Attached is a pic of the one of the cylinders from my engine (ea81). This sat for over 6 months with coolant sitting in the cylinders on one side of the engine. Can this be fixed? can it be fixed without splitting the block? Please give me your input as soon as possible. I didn't want to try cleaning it up without knowing the right way to go about it.
 

[987687]

I'd fill the cylinder with MMO or some other light oil for a few days to get the rust out of the rings. Then carefully try to turn it so the piston goes down in the bore. Then your best bet is probably a brass wire wheel and carefully take the rust off the cylinder walls. It should be fine. It's an ea81, you can't kill 'em.

[NickNakorn]

I'd use the situation as a good opportunity to rebuild the engine properly then you can hone the cylinders and fit new rings too. Doing a proper job is usually a good investment and saves time in the long run. Splitting the block isn't difficult so there's no need to avoid doing it and you'll have a nice refurbished engine instead of a bodged up job.

[ivantruckman]

you will have an oil controll issue in that cylinder

[the sucker king]

I soaked it with PB blaster for a while and scrubbed the cylinders with a green scotchbrite pad, does not want to clean up well. I have a rag soaked in PB stuffed in each cylinder and am letting it sit at least overnight. What kind of abrasive material is it okay to use in there, i need something tougher than the scotch pad I used but don't want to hurt the cylinder walls if they are not ruined already.

[NickNakorn]

In the time it's taken you to do that you could have removed the pistons and split the block...

[idosubaru]

In the time it's taken you to do that you could have removed the pistons and split the block...

 

i'm glad to hear it's not too bad, it's about the only Subaru work i haven't done yet but i want to some day when i have time.  glad to see people tackling it.  i was turned off by block rebuilding when i heard about cleaning, assembling with plastigauge, measuring tolerances, determining if oversized bearings were needed, having the crank checked.....though i guess you can skip bearing size and crank stuff if you're just honing cylinder walls.

 

you're obviously familiar with it, but not everyone works the same. some folks are really slow when it comes to doing something the first time...or just slow in general.  then there's seized fasteners, rust, and parts that require inordinate time to remove, align, or otherwise work with.  i've split a few blocks and it took longer than i suspected...not a surprise, that's how it goes sometimes.

 

for many this could take far longer than you.  a recent head job took me forever...the valve spring compressor i had sucked, the new one i got sucked (after recommendations from others), and getting the springs and keepers all aligned took way too long.  never again...or i'm getting a subaru specific valve spring compressor.  and even still all those valve stems, guides, grinding, cleaning...it was a laborious and lengthy process.  i'm sure some would say that job is also easy.

[NickNakorn]

It's very true that having the right tools and some previous experience is a great help. I'm a fairly slow (I call it thorough and methodical!) worker too but I've years of experience with other cars so I was reasonably happy to start taking my Subaru apart. The most time-consuming part for me was making a little tool to remove the (we call them piston pins or little-end pins here in the UK) wrist pins. And, because I had another car to use meanwhile, I also took my time cleaning and storing all the parts for future use as I removed them. Nevertheless, I think I've saved time and money overall by doing the best job I can. Of course, now I have an engine that pulls like a train and has really good economy too but the good engine has really highlighted all sorts of other problems such as issues with the susspension and brakes - oh well, on we go!  

[skishop69]

Once the rust has penetrated into the cylinder wall material, and it has as indicated by the rust 'bubbling up', the case halves are junk. If you do not have them properly bored out, you will have oil burning (previously mentioned), accelerated ring wear and compression issues. Yes, you could clean it up to a degree and use it if you ABSOLUTELY had to, but it's going to cause problems.

[idosubaru]

to the original picture - that rust at 1 oclock looks bad.  i'm sure someones' tried it before, be nice to hear from one of them and see how bad their oil consumption was...etc.

 

is it possible to pull that piston to it's lowest point and hone as much as you can?
 

i think 'ive heard folks talk before that on some subaru engines (i thought it was the old EA/ER stuff) you can pull the pistons without splitting the block.  pull the wrist pin, then rotate the engine so that the rod pushes the piston skirt up the cylinder bore further....something like that?

 

It's very true that having the right tools and some previous experience is a great help. I'm a fairly slow (I call it thorough and methodical!) worker too but I've years of experience with other cars so I was reasonably happy to start taking my Subaru apart. The most time-consuming part for me was making a little tool to remove the (we call them piston pins or little-end pins here in the UK) wrist pins. And, because I had another car to use meanwhile, I also took my time cleaning and storing all the parts for future use as I removed them. Nevertheless, I think I've saved time and money overall by doing the best job I can. Of course, now I have an engine that pulls like a train and has really good economy too but the good engine has really highlighted all sorts of other problems such as issues with the susspension and brakes - oh well, on we go!  

a friend made a piston pin puller out of machined carriage bolts and made some extras so i've had that for years but haven't used it yet.  thanks for the feedback, i hope to get into one some day.

[mikaleda]

Once the rust has penetrated into the cylinder wall material, and it has as indicated by the rust 'bubbling up', the case halves are junk. If you do not have them properly bored out, you will have oil burning (previously mentioned), accelerated ring wear and compression issues. Yes, you could clean it up to a degree and use it if you ABSOLUTELY had to, but it's going to cause problems.

+1 the slight indentations from the rust could be honed out possibly, but boring it out and using over sized rings would make it a good engine again.

[rdweninger]

I think you have to pull the pistons before you hone the cylinders.  So on to pulling pistons...Also... I'm getting ready to pull the pistons in a spare motor that I plan to 'rebuild' in my spare time.   However, I can not find the required piston pin puller tool.   Can Nick or anyone else post a pic of their homemade piston pin pullers and explain how they work.   I would be forever in your debt.

Oh... it's an EA82 block.   Does the EA81 require the same wrist pin puller?  Maybe I'll start a new thread... eh?

Thanks...

[idosubaru]

my piston pin puller is for an EA82/ER27, it's just a carriage bolt with a small lip machined into the end. with only having dial up at home pictures aren't easy.

[idosubaru]

here's pictures of a home made piston pin puller and a Subaru FSM picture of the Subaru tool is in this thread as well on that same page or one previous:
http://subaruxt.com/forum/viewtopic.php?f=1&t=3575&st=0&sk=t&sd=a&hilit=engine+rebuild&start=30

 

he gets two of the piston pin clips out with just needle nose pliers, which i've heard folks mention before.

 

a lot of detail - but that fairly well documents an ER engine (XT6) coming apart and being rebuilt, which has the exact same pistons, rings, rods, as an EA82.

 

since EA81 and EA82 pistons are very similar, folks that sell pistons interchange them, and not terribly different i would suspect the piston pin clips to be similar.

Edited April 15, 2013 by grossgary

[Gloyale]

I just use a long hook.  Look inside the pin, after removing hte first clip, and look to see the orientation of the clip on the inside, and then try to get your hook into the open side so you are pulling just agaisnt the pin.

 

If the pins are stubborn, there is an alternate way.

 

It's kinda tricky. 

 

1.  remove all case half bolts.

 

2. set crank with 1 and 2 TDC. 

 

3.  Rock case halves open and remove the accesible bolts on the 2 and 4 rod caps. only one of each is accesible with halves rocked open each way.

 

4.   Close case ahlves toghether agian.

 

5.  rotate crank 180 so 3 and 4 are TDC. 

 

6.  Loosen other 2 nuts accesible on 2 and 4 rod caps. 

 

7.  Remove rod caps.  Seperate case leaving crank and 1/3 pistons in block right side of block.  2/4 pistons and rods in left.

[86BRATMAN]

I've always used a slightly modified battery hold down bolt with a tire plug style handle at the end.

[NickNakorn]

I'll see if I can locate the pin puller and take some pics - but it's basically a rod with a little hooked end.

[l75eya]

It's an EA81? Put it back together and start it up. That'll fix it.

I'm here all night! =P

[scoobiedubie]

There is probably rust inside the engine block as well. You will never be able to get it all out. Even if you got is running again, it won't last more than a couple thousand miles. Cut your loses. Get a used one from a junk yard for a couple hundred bucks. Use that one as the core return. You will be light years ahead by not attempting to salvage that block.

[scoobiedubie]

You already have one helicoiled cylinder head bolt hole. That is reason enough to scrap it because you can't get proper torque on helicoiled cylinder head bolts.

[Ibreakstuff]

I use just a battery tie down rod to pull wrist pins, its terribly redneck.. but I grew up in lousiana so its ok.

 

Edit: wow I guess someone beat me to it lol, I left this page open for a few hours before sending the reply.

Edited April 16, 2013 by Ibreakstuff

[Ibreakstuff]

Time serts! I was just reading about how bmw guys replace block threads with time serts and torque them to 90lbs.

 

Helicoils technically could be stronger than the original threads too, if installed correctly.

 

You already have one helicoiled cylinder head bolt hole. That is reason enough to scrap it because you can't get proper torque on helicoiled cylinder head bolts.

Edited April 16, 2013 by Ibreakstuff

[skishop69]

Time serts are the spoob! We use them on Northstars because the head bolts always pull the threads out of the blocks. I wouldn't hesitate to use them, but helicoils on a head.... not so much. Most installers don't get the hole straight and/or use cheap bits that end up having the hole a little too big reducing surface contact and the biggest thing.... very few people use Permatex Sleeve Locker to secure them. I suppose on a Subie block done correctly, prolly not so much an issue.

[ivans imports]

i probly have a good striped down block

[Ibreakstuff]

Slightly off topic, have you ever used the norms thread repairs (ns300l) on the northstar blocks? I've been curious if these would be stronger than timeserts since they have longer inserts (they do have m11x1.25 inserts). Seems to be highly recommended: http://huhnsolutions.com/

 

Time serts are the spoob! We use them on Northstars because the head bolts always pull the threads out of the blocks. I wouldn't hesitate to use them, but helicoils on a head.... not so much. Most installers don't get the hole straight and/or use cheap bits that end up having the hole a little too big reducing surface contact and the biggest thing.... very few people use Permatex Sleeve Locker to secure them. I suppose on a Subie block done correctly, prolly not so much an issue.

Edited April 17, 2013 by Ibreakstuff