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Oil not getting to right cylinder head

Posted: Tue May 12, 2020 8:22 am
by Korto
OK, I've finally rebuilt my bike after snapping the crankshaft, and I'm feeling quite pleased with myself because it's starting with one kick and idling quite happily (if a bit fast. Adjusting the carbs is on the agenda). I'm particularly pleased with myself because I took the opportunity to completely rip out all the wiring, and re-wire it the way I like it, to my own wiring scheme I worked out myself. And it frigging works.

Except for one thing. While the left cylinder head is getting oil, I don't believe the right is. I take the cover off, the metal's hot and dry, with no significant oil to be seen.
As far as I can see, oil is supposed to get in there by the valve pushers catching some mist in the engine case and the oil running down the pusher tube. If the left is getting oil, than there must be mist there, so I'm thinking the problem would be somewhere around the valve pushers, unless there's something I don't understand about how this works. I really don't want to have to pull this whole engine apart again.

Anyone got any advice?

Re: Oil not getting to right cylinder head

Posted: Thu May 14, 2020 11:14 am
by xpatriot
Hi, I'm not an expert, but I did rebuild a 650 however did not run into this issue. I'm not sure how much you can get to now that the engine is back in the bike, but I'd check the oil pump is functioning (quick question- are you running a regular or deep sump and if deep did you have the extension installed and correct oil level?). I think general flow to the rt head is splash from the crank and then once hot mist which is why some maintain mineral oils do better.

I'd just make sure all orifices are clear.....if oid comes in via the valve pushers it has to go out some way and that's worth checking it's clear and a bit of sealer or gasket hasn't blocked it. Good Luck!

Re: Oil not getting to right cylinder head

Posted: Thu May 14, 2020 9:48 pm
by Korto
I'd just make sure all orifices are clear.....if oid comes in via the valve pushers it has to go out some way and that's worth checking it's clear and a bit of sealer or gasket hasn't blocked it.
Thought of that after posting, and pulled the cylinder out enough to pull out the sliders. The silders each have two small holes to let the oil out. One of the holes in one of the sliders looked blocked (probably by over-enthusiastic greasing), so I gave all a blast and put them back.
Has made no difference, unfortunately. I am now 90% certain there is no oil making it to the right cylinder head. But there IS oil in the left head. :?

You reminded me I have an oil pressure guage. Measuring the pressure at idle (all this mucking about HAS made one difference. It's now a lot harder to start) gives me 50psi, responsive to throttle. That seems normal, so the pump seems to be fine.

I've got a normal sump.

One thing worries me now. This is a "new" crankshaft, covered in old grease when I got it. I cleaned the grease off the outside, regreased the slidey bits, and then installed it. I never thought about whether the inside channels may need cleaning. I'm worried this may have been a major mistake. Particularly major, since the only way to correct it will be to pull the entire fricking engine apart again.
This thing needs a "Shooting self in head" smiley for statements like that.

Edit - Wait on, that word "Splash", as in "splash from the crank"...where from the crank, precisely, whould the oil for the RH head be coming from? And would it be different than the LH head? I've grabbed my old crank, and the holes in it that are probably to let the oil out seem to correspond with the bearing, and the left and right big ends. Seemingly, oil is let out under the big ends, flows around, and is then flung off the crank.
Does the 'splash' for the left sliders come from the left big-end, and the right sliders from the right big-end? Because that could account for the difference.

Re: Oil not getting to right cylinder head

Posted: Thu May 14, 2020 10:52 pm
by Lokiboy
The gasket has an oil hole in it to allow Flow. The gasket can easily be put on flipped around and thus blocking the oil. You don’t need to pull off the gasket. Take a coat hanger and push it up the oil hole in the cylinder and pop the opening on the gasket.

Re: Oil not getting to right cylinder head

Posted: Thu May 14, 2020 11:10 pm
by Korto
Do you mean the hole down the bottom? Doesn't that just allow oil out?

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 6:03 am
by Lokiboy
Korto wrote:
Thu May 14, 2020 11:10 pm
Do you mean the hole down the bottom? Doesn't that just allow oil out?
My error. Sorry for the confusion

Here’s a link that explains the Oil flow better for trouble shooting viewtopic.php?f=5&t=56113&p=717190&hili ... le#p717190

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 9:13 am
by Korto
Thanks for the link.
...
...
That diagram's clear as mud. :puzzled: :lol:

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 10:11 am
by Tomcatfixer
Interesting post.

My first question is, why is there any grease inside your engine? A new old stock crankshaft might come covered in cosmoline, as a corrosion preventative (the new-style 2015 "D10" crankshaft I ordered, pictured below, did not), but requires no grease; it's lubricated with engine oil. I would suspect that any grease that heats up to the point that it can "flow", like oil, could congeal when it cools, which could be bad inside an oil passage, where it could block oil flow, especially during engine start-up. Unless, of course, this grease gets diluted and dissolved into the oil, which then begs the question, "why bother using grease"?

As I understand Ural engine lubrication, oil is directed and splashed into the slingers, which fill through centripetal force, then direct the oil into the holes to feed the internal big end bearings, the opposite of what you indicate.

2020-05-15 09.53.18.jpg

Regarding the crankcase holes under the tappets...

2020-05-15 09.59.51.jpg
2020-05-15 09.50.57.jpg

...I don't fully understand their operation. It would seem to me that with the crankshaft's counter-clockwise rotation (refereced while seated on the bike), the crank could easily sling oil to the left side holes, as the oil slung from the top of the crankshaft rotation is aimed directly at the holes, but the right side holes are oriented at an awkward angle to receive slung oil coming up from below, as the right side of the crank rotates up.

Some oil obviously flows between the tappet and tappet guide, but the fit is so tight that I doubt this quantity of oil would be sufficient to lubricate the rockers in the head, so it must make the awkward bend in directional travel to enter the crankcase holes below the right side tappet guides.

I hope some more knowledgeable folks chime in here.

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 11:00 am
by Korto
Just so people are clear, my bike is a dnepr MT9, NOT a ural. I mention this because that tappet and tappet guide above does not look at all familiar.

I didn't address how the oil gets into the crankshaft, which I assume is via magic, but the two journals each have a hole in them. I assume this is to let oil out to oil the big ends, as I can see no way in hell oil could actually get in that way while the shaft is spinning.

The grease is there because after I cleaned the shaft, I then had bare metal that I was going to attaching other bare metal to, and that just seemed wrong, so I put grease on. If that was a mistake, it wouldn't be the first.

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 11:05 am
by Tomcatfixer
Thank you for pointing that you own a Dnepr. I wasn't paying attention.

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 12:21 pm
by jeffsaline
For putting rotating parts together in engines you might consider getting a small bottle of Maxima Assembly Lube. My local independent shop carries it on the lubrication shelves and it costs about $10. It is red and smells like cinnamon so you can easily tell when you've been using it. It will stay in place longer than oil when you first start an engine and is good until normal oil flow reaches the parts. It is good on seal lips too.

I am not familiar with the engine you are working on so please take that into consideration with what follows. My guess is the oil pressure system works with a fairly low pressure. I'll also guess tolerances are generous in parts. I wonder if oil isn't following the path of least resistance and if there is a clogged, or maybe even partially clogged passage oil will move out of the pressure zone at a different location. It doesn't take a lot of oil to lubricate a ball type bearing so low flow is ok. IF there is a clogged oil passage in the crankshaft that should transfer oil to the right side of the engine oil might just be exiting at earlier opportunities in the oil system. I fear you might need to take the engine back down and clean and check all oil passages in the case, crankshaft etc. to verify the passages are clear and pass oil.

Now just a short story from about 17 years ago. A local guy bought a BMW airhead and had some trouble doing a tune up. He also had an airhead he had owned for many years that was out of service with a damaged left cylinder and piston. He was a poverty rider and I did a lot of work to help him out and get going again. I think I had about 3 weeks into his machines by the time he had a running bike again. We decided we should put the R100 top end on his old R80 case and that way get the better of the two bikes running. Soul have been an afternoon job and so it was. Until we went to start the engine and I wanted to start it with the valve covers off just to verify oil flow to the top ends of each cylinder. The left side had oil flow in about 5 seconds after start up. No flow to the right side. We installed the left valve cover as it makes a mess when the oil is flowing well. Ran the engine again and still no flow on the right side.

I was sure I had the right side put together correctly as I've done a few top ends on airheads. I got an oil can with engine oil in it and had him squirt some oil on the rockers while the engine was running just to keep them lubed. I bet we ran that engine for 15 minutes and never got a drop of oil from the engine on the right side top end. I took the right side apart and verified it was put together correctly from what we'd done. No problems noted. Still no oil flow.

We decided to put the R100 bottom end in the bike and put the top end back on it. So I swapped in the R100 bottom end and installed the top end. Started the engine and had oil flow in less than 10 seconds. Fixed a timing issue with a different advance mechanism and rebuilt the carbs and did a really good tune up. He had a running airhead again. It said R80 on the starter cover but was an R100. The owner was really happy.

We had talked about the R80 engine case that didn't have oil flow to the right top end. He told me about 10 years and he guess 30,000 miles earlier a BMW shop in Minnesota had replace the main bearings for some reason. Then he wrecked on the left side and the bike had sat for about 4 years. He offered me the R80 engine bottom end to play with as I was intrigued as to why it didn't have oil flow to the right top end. I removed the crank from the case and probed oil holes in the case.

When a front main bearing on an airhead is installed it is pressed in place. It isn't a ball or roller bearing but a babbitt bearing. Once installed in the case 5 oil holes must be drilled into the bearing to allow oil flow. The shop only drilled 4 holes and missed the right side oil feed hole. So that engine had run for about 10 years and 30,000 miles with no pressure feed oil to the right side top end. I measured all the valve train parts that hadn't been pressure lubed for that time and could not find any difference in size from the left side parts that were pressure lubed. I've still got that engine case and crank and someday might just drill the last hole and put that engine in something.

Good luck with whatever you decide to do.

Best,

Jeff

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 2:35 pm
by RC20
The grease is there because after I cleaned the shaft, I then had bare metal that I was going to attaching other bare metal to, and that just seemed wrong, so I put grease on. If that was a mistake, it wouldn't be the first.
Per the above, assembly lube or even just oil if its going to sit and possibly rust, grease is a really bad thing to have inside an engine.

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 8:21 pm
by Korto
OK, everyone's agreed that using the grease was a "bad choice", and may be the cause of my problem. I need to pull the engine back apart, as soon as I can make garage space again and clean it all out.
Bugger.

What's a good grease-remover for a "poverty-rider" to use inside the engine? I've been using petrol, but there's a lot of advice against it.

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 8:58 pm
by Tomcatfixer
My favorite rubber-friendly solvent is kerosene.

Re: Oil not getting to right cylinder head

Posted: Fri May 15, 2020 9:22 pm
by Lokiboy
Since you’re pulling it apart, LeMoto site has really good info and specificity how to test if your oil will flow properly within the engine.
https://lemoto.info/c4%3A-engine