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Discussion Starter #1
Ok wow guys. I hope everyone is doing great. So the Bike had been running great until we was on a ride the other day fighting a 40mph steady head wind with gust to 70. It was a hard day. I couldn鈥檛 hear anything because wind was so strong so we just cranked her up to 85mph and cruised for a couple hrs constant. Everything was great. All of a sudden I felt a slight power drop. Still can not hear anything but the darn wind but the power dropped from 85mph to an put 70mph. I let off gas then rolled back on and brought her back up to 85mph. Held steady for another 40 or 50 miles. Then pulled off for fuel and when I pulled up to the pump I could hear the bike again. I heard it knocking. I thought shoot I just checked oil before I took off today what is going on. Removed 7 layers of clothes and hats etc to keep me warm. Then I started her back up after checking oil. Oil was fine. So started her back up and now I can hear her knocking and clanking. So pulled over to side of truck stop and let her cool all the way down. Checked what I could as I am now in the middle of nowhere Missouri. Started her back up and she is still knocking pretty good. I then got back on highway and wow she鈥檚 clanking now. Once I got up to speed the sound was much better but still there. I made it about 8 miles down the highway and stopped off at next exit. Now I have head gear off and I can hear it clanking. I made some calls and had a trailer come get me Tryin* not to cause more damage as I know this sound is bad. So I get her home and tear apart and holy cow. The rear cylinder has gotten so hot it tore up the back of the piston. (Exhaust side). I found that the exhaust pushrod was also hitting on the tube hard. Made defined witness marks. So my question is this. my oil pressure never dropped under 28psi. This is where it pretty much has stayed since installing the S&S oil pump. If the exhaust pushrod is hitting the tube hard enough to prevent it from pumping oil up could this have caused the back side of the piston to melt. It鈥檚 a lubrication problem. When I tore apart the top rocker box did not have much wet oil either. What should my checklist be? Li know this motor is shot but I will need most parts to build another and don鈥檛 want this to happen again. Here鈥檚 pics of the rear piston. 10k miles on it. Damn it was running good.
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How do I bench test these fueling race lifters?
 

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I would think that would be heat and lack of lube from the bottom end, what's the front cylinder look like? Is the oil sprayer under the piston broken off, lose, or clogged? Oil doesn't come from the top down through the cylinders.
 

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OK, I have a little more time than I did earlier today. All that carnage just says it was to hot and trying to seize. To hot made it tight, or to tight made it hot, flip a coin at this point. Based on that glossy jug, I'd hedge towards to tight on the rings.

We need to see the other side of the piston, and we need the see the pin sides to.

Lets see the mating faces of the compression rings.
 

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Wouldn't rings gapped to tight cause the landings to beat out, of course maybe that's why the lower scraper is gone.
 

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Too hot or too tight will cause scuffing and eventually lead to scoring.When you "squeeze" the oil out between the surfaces the transfer of metal between the cylinder and piston wreaks havoc.
Also,too tight, too lean, too hot (lean),oil dilution with fuel from being too rich are all possible causes.
 

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Also,too tight, too lean, too hot (lean),oil dilution with fuel from being too rich are all possible causes.
Yep. (y)

Brian, you've been through a steep learning curve based on your recent posts in this forum. Your current situation is the result of a layman building a high compression, air-cooled engine and beating the crap out of it. The cause for this failure may be listed above but may require one with experience to put their hands on all of the pieces to properly solve this puzzle.

In a previous thread you were chasing some top end noise and were advised to check interference with the pushrods and the covers. Above you said, "I found that the exhaust pushrod was also hitting on the tube hard. Made defined witness marks."

The pushrod hitting on the cover probably didn't cause the failure. But finding this issue after your engine self destructed, when you knew to check it weeks or months ago, tells me that you do not posses the qualities of a person that should be building a high compression air-cooled engine subject to the demands that you require. You might get away with over looking a minor detail, a small miscalculation on the tune or a slight clearance mistake when you're running WOT for 10 seconds at a time. Running 85 MPH into a 40+ MPH headwind for two hours is more like an endurance event and you better damn well have everything right before trying it again. I predict similar events in the future unless something drastic changes.
 

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This^^^ makes me wonder where that bottom oil scraper ring is. Was it ever there? You would think there would be some sign of it but I don't see it. Need more pictures.
 

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i agree that rhe bottom oil ring,, should show some signs of having been in place,, and how it just disappeared.. its a high tensile steel ring? a guess would be,, the oiler nozzle somehow failed,, and caught the ring,,,

the damage to the piston, looks like lack of lubrication, to the thrust face clearance
,, or both
 

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Discussion Starter #15
I pulled the bottom scraper ring out before taking photo is why you do not see the bottom scraper. As for the pushrod hitting the tube I did have the same issue a few months ago and took it back apart and cut the inside tubes down to help prevent this. It had been running quiet and great. The rings were gapped via computer and shipped to me installed in the jugs Already. I could look up the gaps but they were in spec. On last post I had just began tearing into it. Oh sorry it鈥檚 06 Electra glide With a 107鈥 kit. So now I have it all the way down and the only place I have found any witness marks are the lifters and the two exhaust pushrods. On the pushrods they are minimum but the bottom of the lifters are pretty scarred up. I measured the bore and it was just right on the limit of specs according to the book. I haven鈥檛 tested the piston jets yet but the lifters are all clear. Pushrods clear. Would a bad intake or exhaust valve cause something like this. This drastic. Second wouldn鈥檛 you be able to hear it if it was a bad valve. I installed a in dash of鈥 pressure gauge and it never lost any pressure at all. I鈥檒l check this to make sure it鈥檚 working. new pressure plate,oil pump,piston coolers, everything. It had to be lack of lube to get this hot I just haven't Found out why. . Here鈥檚 the shots all the way around. The front doesn鈥檛 have this issue. Or should I say didn鈥檛.
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like I said I did remove the lower scraper Before taking any shots. It was seized into the gap of piston and was very difficult to remove. Thanks guys. All your help is wonderful.
 

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Do you have pictures of the other piston/cylinder to see how they compare? Was the scraper you removed broken and was it entirely in the ring groove like the top one? I'm not surprised it was stuck the way the piston looks but with damage on one side and not both seems like a ring problem or trash in between the rings at that spot. Don't see how this damage is from the topend (valve train) unless it's trash in the oil from the top, but if there is any marks on the lifters I wouldn't use them, show a picture too.
 

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the bottom of the lifters are pretty scarred up.
The roller? What does the cam lobe look like?

I measured the bore and it was just right on the limit of specs according to the book.
On the tight side of the limit or the loose side? What was piston to cylinder clearance and was it measured with a torque plate on the cylinder?
 

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Discussion Starter #18
I will have to go back through the book but I sent the jugs off and had the Pistons sized and rings gapped for the exact bore which they provided. The company I hired to do that did all the piston to jug measurements etc. as for the cam they have some marks where the roller was rubbing off on them. Not scored to point you can feel with yourself fingernail but you can see very slight witness marks. It鈥檚 the sides of the lifters not the rollers that are scored up. The lifter bore was on the loose side of the spec. The oil ring was not broken I had to break it to get it out. Maybe when I installed the piston into the rod I slipped and allowed ring out of place but man I swear I triple checked. But hey I鈥檝e done much worst. I will send some photos when I return today. When I originally removed I thought that the oil scraper must have slipped off and I didn鈥檛 catch it because of the look and marks in the piston looks like the same design as the oil ring. Then a friend said that also could have been just from heat. ?? I just don鈥檛 know other then me making the mistake on the Install what else it could have been. I tested everything and replaced 98% of everything. How would you not realize that though after installing and spinning your rear wheel to confirm your not in a bind and everything operates smoothly.?? Is there a way to test the camplate other then purchasing the tool?
 

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OK, now some questions.

How did you measure the jug, exactly? And did you measure the piston clearance to the jug, as in with a feeler gauge? Or calculate it?

Now some observations and things to consider.

I don't see any cross hatch in that jug. That would be a big issue.

And with the damage all on one side of the piston, that is usually piston fit. But on a Harley can indicate a bad rod. Are both rods free to rotate independently on the crank?

Past that, the jug has been smoking hot, but the piston does not read lean, so that again points at piston fit.
 

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Past that, the jug has been smoking hot, but the piston does not read lean, so that again points at piston fit.
Piston fit would have shown quite a bit sooner than 10k miles, wouldn't it. Or does it depend entirely on how poor it fits?

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