TOPIC:

Please don't take this the wrong way. If we are talking about the big end of the con rod, it has PLAIN BEARINGS just like the plain bearings on the crank main journals. There are conrods in engines that have the small end (wrist pin end) bushed with a brass or copper bushing which is replaceable. The KZ and ZN do not have bushed small ends in the conrods.

Plain bearings are a copper shell with a Babbitt ( Tin Antimony Lead and Copper) facing and are capable of extremely high rotational speeds when supplied with a feed lubricant which prevents contact between the plain bearing and the shaft or journal the bearing is running on.

The turbine /generator shaft in the nuclear power plant has 14 journals around 60" in diameter. The rotating mass of the 3 turbines and the generator rotor is about 420 tonnes spinning at 1800 rpm. All of the plain bearings are Babbitt bearings. The oil pressure carrying all of this weight is just over 100 psi. If the lube oil failed and the rotating mass got loose the estimated location of the rotating mass would be found 18 miles away from the turbine generator housings. Most interesting part. If the lube oil was on, you could turn the turbine generator mass by hand.

Please don't take this the wrong way. If we are talking about the big end of the con rod, it has PLAIN BEARINGS just like the plain bearings on the crank main journals. There are conrods in engines that have the small end (wrist pin end) bushed with a brass or copper bushing which is replaceable. The KZ and ZN do not have bushed small ends in the conrods.

If you are talking to me I'm not sure what you are clarifying... Actually, the crank main journal bearings are a mix of plain and with a groove, the conrods big ends have plain bearings, small ends none.
Yes, even in huge marine engines they are made from Babbitt, and same in turbines. We had a couple feet long special tool for scraping them to proper size. In the old bikes we used bronze.

What I'm trying to achieve is sorting out what we have. Mine came all from different engines. I'm simply wondering what these codes exactly mean, and if there is any relevance to their install order and position within the engine. Of course I know about the little directional notch the bearing shell have I'm also speculating on the history of the parts I got, trying to have a bigger picture of what I'm dealing with. But that best left for my own thread, don't want to divert this one away from the main course.
Cheers, Stan

Ok, latest developments:

New shaft coupling boot arrived from Finland and also the water pump mechanical seal from Philippines got here. Cheap eBay finds despite both being brand new.

I have also found a guy who for little money can ultrasonically clean the crankcases and the crankshaft, to clean all the crud out of all the oil ways. Certainly needed as I just took apart the oil pan and flushed those oil ways out with carb cleaner, and LOTS of black cr*p came out. However, the guy pointed out that if I did not take the conrods off the shaft, his cleaning would not get to the oil passages inside the conrods. However, he also said that he COULD get to the shaft oil passages and whatever was left in the rods was not worth taking them apart for (and then having to get new bolts to put them back together again). He also said that these had been apart before as all of the conrods were stamped... confirmation that my engine has been 'at' before. I am picking up the cleaned parts tomorrow. Then degreasing little more and paint-and-bake.

Attached pics of all the bolts with painted-and-baked heads, and all the covers, sanded and masked, ready to be painted-and-baked tomorrow.

Onwards and upwards!

Ultrasonic cleaners work great for cleaning external surfaces. They don't work on internal surfaces. Some people think that cleaning carbs in ultrasonic cleaning machines is the ultimate, but it's not. The high frequency waves that the transducers produce radiate through the cleaning media and attack the surface facing the transducer and that's all. Small ultrasonic tanks have 2 transducers, (one on each end) larger tanks like 2 - 4 gallon tanks would have 4 or 5 transducers.
Bottom line, for what you need to do, a tank with lacquer thinner or acetone and a good scrub brush and an air hose would be more than adequate.

As far as cleaning the crank - Pull the rods and mark everything. Keep the nuts and bolts together with the rods. Reassemble everything as units just they way they came off of the crank. Torque everything on reassembly and you'll be fine.

I have also found a guy who for little money can ultrasonically clean the crankcases and the crankshaft, to clean all the crud out of all the oil ways.

Whatever you do, the engine will need to go through the break in period. Mine did and it's fine, as I observe it. Yet I'd be more aggressive next time around taking extra protective steps. First, I'd use what I used - Rotella T4. But not until the first change after 50 or 70 miles. I'd start the engine up, let it run for a few minutes, not even until fully warms up, and change it. Fill up again - change again after that 100 miles. Then - do the 500 and 1000 mile changes. Including filter each time.

My point is, change oil after the first 5 minutes it runs. Then do the first 50 miles before next change using really good organic non synthetic oil, best quality. After that, Rotella T4 is just fine.

STan

Thanks Kawboy and Stan.

The guy said that after the ultrasonic, he would put them a 'cleaner' bath and air hose blow everything out. I'll chat to him about taking the rods off.

I'll be using special assembly oil, a slightly more sticky/slimey oil that is used for assembling engines and running for the first few minutes. Then oil change and do the first 500 miles etc.

But I am still WAAAY off that ... lots more to do before that.