Long story short i'm in the middle of a full rebuild on my 96 LC. The top of the block ended up needing to be decked and everything else was very clean so I was expecting to be able to reuse the bearings and pistons/rings. However I opened it up and found lots of scratches/scoring/gouges on some of the bearings. Some spots on the crank look like it'll need some love so i'm guessing i'm now looking at a whole bottom end refresh. What have you guys done for bearings besides OEM? Just looking to weigh out options since this was not exactly in the budget at this point. Though i'd rather do it properly once and not worry...
Main & Connecting Rod Bearing Options
- Thread starter Wompom
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I don't see anything too scary there. 'Mic' all your journals and if they are within spec...polish them (lightly).
Get some Clevites, plastigauge each journal on trail assembly and if everything checks out O.K., run it.
Get some Clevites, plastigauge each journal on trail assembly and if everything checks out O.K., run it.
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Those bearing look great, how many miles are on them?
bjowett
Supporting Vendor
At a minimum, send your new rod bearings to be moly coated.... $30 - $40 is cheap insurance in a variety of situations plus longer life.
- Thread starter
- #7
Unknown. Came out of a truck with over 200k but doesnt appear to be the original motor. Even with scratches and some gouges on them? I thought compared to photos of newer ones they looked trashed. Ill post more photos of them. This is my first time building a bottom end and its making me a little OCD.
Never heard of doing that. I'll look into it.
2fpower
SILVER Star
I agree with Tools, they look great. not even down to the copper color layer.
I used clevite bearings from Rock auto.
Here is a bad bearing.
I used clevite bearings from Rock auto.
Here is a bad bearing.
- Thread starter
- #9
My fear was more so the scratches/gouges in the bearing less so that they were worn out. Is that typical? Trying to decide if i just go OEM with the same size bearings or go aftermarket and have the crank ground to fit standard sizes all around. This one in particular had a huge gouge in it and deep scratches. Is this caused by debris getting into the crank case?
2fpower
SILVER Star
Quick question, are you planning on running this on a Nascar track?
My point is that the bottom end of this engine is WAAAAYYYYY overbuilt. If you are perfectionist, spend the money. Personally, I would not hesitate slapping new bearings and run it for another 200k miles. Can you feel a grove in the crank where that last bearing came out of?
If you want another opinion where they can do a good inspection, find an honest machine shop and see what they think.
My point is that the bottom end of this engine is WAAAAYYYYY overbuilt. If you are perfectionist, spend the money. Personally, I would not hesitate slapping new bearings and run it for another 200k miles. Can you feel a grove in the crank where that last bearing came out of?
If you want another opinion where they can do a good inspection, find an honest machine shop and see what they think.
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Yep, could have happened when it was first started at the factory. Not significant to performance or life.
- Thread starter
- #12
No - just someone who went to school for mechanical engineering and stuff like this makes the OCD trained into me wonder.
There is a scratch at #3 i believe i can catch a nail on, but not a groove all the way around. Im dropping the block off tomorrow morning so may just take the crank and bearings and all with me to have em take a look.
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Why? Its a 7 main, lightly loaded, with a great oil system, 6cyl motor. Have seen them with over 300k mi that I wouldn't hesitate to continue to run. Modding the bearings would have what benefit?
2fpower
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Sounds like you are on a good path.
Definately you should be awarded points for having the confidence to tear into the engine and for asking questions when you see something that does not look quite right.
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The bearing forms kind of a dam, creates a small clearance to the crank where a pressurized oil film lives. In other words, as long as there is good oiling, the bearing should never touch the crank. The pictured rod bearing has touched, the bearing surface is soft, if the clearance was not exactly correct, will clearance during engine break in. Look at the rest of the bearing surface, looks like factory machining over most of the surface, shows good oiling and little if any wear.
The oil system from the filter to the bearings is short, little opportunity for debris to get in. It's common for there to be debris when the motor is built, almost impossible to avoid. The other time is when the filter is changed, easy to have debris fall into the filter/opening. One of the reasons I don't agree with over servicing the oil and filter. Again, the bearing surface is soft, so the particle embeds in the bearing surface and rides there for life.
inkpot
SILVER Star
If the scratches/grooves look like a pad of steel wool, then you may have a problem. If they are few and far between, not so much. All they do is hold a little extra oil.
bjowett
Supporting Vendor
Coated bearings are their benefits are well established, there's plenty of reading out there. Everything about the bearing is better, the seize resistance and cold start protections go off the charts. Given that the crank will not be going to a machine shop for inspection, cheap insurance. Tolerance will be tightened .0001 - 0003.
@Wompom some of the bearing scratches look perfectly normal, I personally wouldn't put them back in with those big gouges in them though. For less than $100 you should be able to lay in brand new Clevite main's, thrust and big end bearings. They are Japanese made and probably an OEM supplier for Toyota.
- Thread starter
- #19
Are they available in the same bearing sizes as toyota OEM? I thought anything aftermarket required grinding?
If thats the case i'll definitely consider that.
Found this in a different 1fz today.
Yes and no. Toyota spec's the bearings out to .0001 whereas standard spec and what you will get from Clevite will spec out to .001 The difference is incredibly miniscule. I debated back and forth with this for a long time when I did my rebuild. What I came up with was that a couple of .0001's wasn't going to make enough of a difference either way. Your talking about less than the thickness of a coating of oil.
However, you can get oversized Clevite bearings if you wanted to have the crank ground down. Once again they are .001 spec.
