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Thought this might be appropriate for this thread.
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OK, well first I want to warn you about not using any abrasive on those crankcase faces, even fine grit…Be very very careful, taking off any meat on either side will cause the crankshaft to bind. Next, I will go on to say that the crank seems to rotate freely even with the crankcase halves snugged up, so I would agree that the crank does not appear bent. Next, I want to ask you why those taper pins seem to be in place when you are rotating the crank without the halves assembled? Next, I wanted to ask about the videos of rotating with both pistons/rods connected, were the rings in place?? If so, it doesn’t appear that there is too much rolling friction. If there were no rings installed, then perhaps there was too much rolling resistance.
Next, I want to question the color of the paint on the powerhead. I saw a picture/video and the blue seemed too bright, but I can’t find that picture/video now. Perhaps this is just due to video/picture quality, who knows. Is this engine new to you? If so, did you every have it running? Was the powerhead stiff when you got it? Or, did it get stiff after you ran it? Again, forgive me if I forgot the details of some of your older videos/pictures, but were you rotating the powerhead with the gearcase connected? If so, perhaps it is the gearcase that is stiff, or perhaps the new impeller is stiff.
You mention something about the part numbers of the rods being visible, but that doesn’t mean the caps are connected to the proper rod, or oriented properly on the correct rod. While it surely is possible that a messed up rod bearing could certainly cause the engine to be hard to rotate, I just want you to be sure everything is OK before reassembling. Once the new rods arrive, you should assemble them to the crank (with caps properly oriented), and rotate them around the crank, there should be little or no resistance. But, I guess before you do that, you should look at each new rod, find the line up marks, and mark them carefully with a permanent marker to ensure the caps stay with the proper rods and the caps stay properly oriented on the rod. I know I keep pounding this point, but it is an easy mistake to make. And it is not too hard to mix up the rod caps, especially when unboxing and pulling them apart. So, I want you to mark each rod carefully before you pull it apart to ensure things don’t get mixed up. And yes, new rods will take care of any rod fit/cap orientation/cap mix up issues. But, I just want to be sure you thoroughly understand what I am referring to before you start to work with the new rods. Nonetheless, I want you to post a picture of at least one old rod with its matching cap assembled showing the line up marks I referred to (don’t assemble the rod to the crank).
At this point, I am not convinced of anything…Starting with whether or not this powerhead has been apart before. Perhaps you can take some more pictures the powerhead and midsection showing the paint. The only thing I feel confident in concluding is that the crank is OK/not bent, and its rolling resistance in the block seems normal.
Again, we are here to ensure you are successful with this project, so please don’t be put off by my continued questioning. I am not there, so can’t see everything you see.
Tonight I removed the pistons and cleaned up all the journals and crankshaft with 400 grit carborundum very carefully.
The attached video shows how the crankcase can be turned without the pistons. I also spun the crankshaft in the case without the top cover. It rotated smoothly with any wobble at all, so I believe the crankshaft is straight.
I removed the top 2 piston rings from each piston to measure the gaps, bottom had ~.002, top had ~.005. The.002 is too little, the .005 is on the bottom end of ok. I was expecting more ring gap. Before the pistons came out I could move them by hand when they were in the crankcase. If had to file the rings there is the gap, a lip and then the rest of the ring. Filing that lip would be difficult to do with my dremel tool and a rotary file. The lip is very thin and just touching it would remove the ring material very quickly. Filing it by hand would be risky as well.
The crankshaft bearing measurements are greater than spec. It was difficult to get measurements with my digital caliper, it was around 20 degrees in the garage. I was careful in polishing the crankshaft journals with the 400 grit. You can see they are not quite polished.
The cylinder walls were smooth top to bottom.
Please advise on where to go from here. Ed Elliott has new connecting rods and all the gaskets needed to put this back together.
Thank you for your patience and time.
OK, this video is where I took note of the powerhead color. That blue is too bright to be original paint, but again the video quality may have distorted the color. And yes, you should not have to file the ring ends to get them to fit. Something is wrong if there is no ring end gap. I still think someone was inside this powerhead before…
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