Advice about bad bearing, rod, and crank
 

I just picked up an engine to rebuild. (link to for sale thread here http://dsmstyle.com/forums/showthread.php?t=16256 ) I just pulled the crank and found a spun rod bearing. There's some slight scoring on the crank. The rod is smooth in the center, but the outside edges are a little chewed up (kind of rough, but no deep gouges). I'm looking for advice. Since it was recently rebuilt I had hoped to only mess with the bottom end and leave the head on and in tact. Not sure if that's possible now. So:

1: Do I need a new rod or since it's just on the edges can I buff the damage out or leave it (and thus avoid pulling the head)

2: What should I do about the crank? Can slight scoring just be buffed out or would it need to be bored? If so, is it better just to get a good condition crank?

Re: Advice about bad bearing, rod, and crank
 

Sounds like the crank will need to be cut. Generally, if a crank is damages like that at all, it can't just be polished out. But without anyone actually looking at it, no one's going to be able to tell you. I, personally, wouldn't reuse the crank OR the rod

Re: Advice about bad bearing, rod, and crank
 

Bring it up to Crankshaft Supply. They'll inspect it and tell you what needs to be done.

Re: Advice about bad bearing, rod, and crank
 

Thanks for the input so far guys. I was in a rush earlier, but after a closer look at the rod I don't trust it at all. I'm just going to have to do things the hard way and pull the head to replace this bugger.

I'll try to have the crank inspected. I'm leaning towards replacing it VS having it machined if it's not reusable.

Any more opinions would be greatly appreciated. I'm sure I'll have a ton of questions in the near future as most of this is first time stuff for me.



A some what related question. I'm wondering if I should get a new oil cooler for this thing. I'm not sure where the cut off for engine failure and replacement is or if flushing it is even remotely reliable. I'm thinking better safe than sorry.

Re: Advice about bad bearing, rod, and crank
 

Shoulda bought a 2.4 :D That is honestly what I would do, use the front side parts off that one to build it up. it is not really any harder than a 2.0 build.

Re: Advice about bad bearing, rod, and crank
 

I've thought about it and I may do something more extreme with the goodies from the engine currently in my car in the future. I got this at a good price and it's a hopefully inexpensive way to cure the low compression that's been driving me crazy. Not sure if you saw the link, but it's been recently rebuilt so aside from the bottom end damage is hopefully in reasonable shape.

It was funny though. I showed up to buy a couple pieces of side molding and went home with an engine in the back of my Talon. Who'da thunk it.


Also, I'd rather learn on something cheap, because likely as not I'll screw something up. :P

Re: Advice about bad bearing, rod, and crank
 

Yes that motor was rebuilt... But it was rebuilt with TOPLINE parts. I'd do a complete rebuild, gaskets, seals, pistons, all of it. But that's just my opinion. Also, I got the coolant overflow from that car. And there was a mud type substance in there, I'd get everything hot tanked just to be safe while you're at it.

Re: Advice about bad bearing, rod, and crank
 

How much did you get the block for in that condition?

Re: Advice about bad bearing, rod, and crank
 

$200 with head, intake mani, TB, Fuel rail and injectors, 90 oil pump housing, etc...


I'd love to go with better rods and pistons, but I'm on a budget here and accepting it will have to be pretty basic. Most gaskets will be replaced with mitsu stuff. I'm planning on TRI-Metal bearings in the bottom end, APR head studs up top, new main studs. Even if I had the $$$ to do the rods and pistons I don't know whether the cylinders were bored. I dunno. This is a lot to tackle without having planned on it and I'm a bit overwhelmed.

Re: Advice about bad bearing, rod, and crank
 

This is a spare block right? Just accumulate parts. After all, you don't need it this second. And while you're replacing those bearings, check out the cylinder walls. You just might need to get it bored anyway. I'm not sayin to buy forged pistons or anything, but I'd take mitsu oem over topline any day.

Re: Advice about bad bearing, rod, and crank
 

Unfortunately due to work I will not have any large amount of spare time for, oh say, 4 years... All of that starts in about a month. That's why i was in a bit of a hurry. Now that I pulled the head I might just end up waiting longer and build it better. I was expecting the head at least to be in reasonable condition since it was supposedly rebuilt, but obviously it was not. I can see light through half the valves when I shine a flashlight through. Pictures of all this fun coming in a few minutes.

And yes, it's a spare block. Mine runs fine, but has had low compression for a while. In theory I can wait but I wish I didn't have to.

http://img59.imageshack.us/img59/5229/bearingsdc7.jpg

http://img217.imageshack.us/img217/4986/crankng4.jpg

http://img217.imageshack.us/img217/1...derwallqs8.jpg

http://img217.imageshack.us/img217/3774/rodzx1.jpg

http://img61.imageshack.us/img61/3857/valvescl9.jpg

Re: Advice about bad bearing, rod, and crank
 

I know exactly how ya feel man. But it's better to do it right the first time, than to have to keep ripping it apart for stuff you skimped on.

Re: Advice about bad bearing, rod, and crank
 

That does look pretty bad. Do it right the first time, you can take out a turbo when you pop an engine too.

Re: Advice about bad bearing, rod, and crank
 

Turbo doesn't matter so much. It's a cheapy small 16g that I hope to replace in the not too distant future, but the attitude is about right. I just spent some time talking to a machinist about options. I'm going to bring some parts in to be looked at. Waiting to hear back about a crank, rod and piston combo before I make any big decisions.

Re: Advice about bad bearing, rod, and crank
 

That crank definitely needs to be cut, or better yet, replaced with a decent used one. And definitely make sure you use a new oil cooler, you can't really clean out a bad one properly.

Re: Advice about bad bearing, rod, and crank
 

The topline rebuild kit on ebay is cheap, lets say someone I know, absolutely not myself, bought one....

will the engine fail? how can it if the bearings are installed correctly?

just looking for some constructive criticism, no flames please, if my budget for an engine rebuild was $3000, it would have been doen correctly.

Re: Advice about bad bearing, rod, and crank
 

You pay for what you get, the parts are made cheaper somehow, quality/location etc.

Re: Advice about bad bearing, rod, and crank
 

The crank can easily and cheaply inspected and cut and polished. Then its just using different bearings. Nothing wrong with doing it and often a great idea since many cranks are often not checked for several rebuilds.

http://www.partsamerica.com/ProductD...pe=529&PTSet=A

I've actually used their reman. crank b4 and good results. Has a warranty and bearings.

Toss the rods, any knocking will egg-shape the rod end and just cause more spun bearings.

Cross hatching looks good as long as there isnt too much ridge at the top. And I don't like Topline parts but I have used them b4 and haven't had a motor fail. Its kinda hard to make a bad bearing other than burrs (which you should check for anyways, regardless of brand. These are mass-produced and spot checked for quality). Rings, etc are usually hard to screw up other than using lower quality materials. But even them they shouldn't fail quickly. It's 90% user error. Whether poor bearing clearance, weak oil pump, over-rev, etc. its usually not bad parts. Just a poor rebuild.

Check the cylinder bores for out-of-round and size. If they are on the large size, just get the cylinders bored to the next size. Id also recc. getting the block hot tanked, have the head freshened up with new stem seals, make sure to check the guides, relap the valves if needed. New oil pump is a must unless the current one is new. But I would at least take the gear drive apart and check the case for wear around the gears. Replace if there is ANY wear.

Take your time and check everything. Its free to do inspections, but not free to fix the lack of.

Wiz