OS.30 Carnage

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Oh aint that nice.... looks like the lower rod bushing was not getting lubed enough..... sure sux it let go in that fashion......I have a .18 cvrx that must have about 4 gallons on it by now...... Guess is time I pull it down and check it all out.....
 
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Not bad. Would have been more entertaining though if the rod would have seized to the crank and broke one or the other. Lube is one possibility like Jam said, another is excessive high temps.
 
Ive only run quality fuels. Started with Odonnells then Werks so lack of lube shouldnt have been a problem. The mill has never been run hot. There must have been something internal that caused the bushing to fail.
 
Well after carefully looking at the pix again, sure looks like the rod is mighty dark and the end of the crank also looks very dark.... the discoloration is a sign of heat in any engine......heat only comes into play if run seriously lean causing the discoloration and ultimate failure of the rod lower bushing.... which in turn destroyed the crank and the engine case..... in any case sure is nice pix.... :lmao:
 
I would like to see the rest of the engine parts also, I bet the top of the piston is burnt and the sleeve is also discolored around the exhaust port area.......
 
Yea, should have taken more pics before I tossed it. The piston sleeve looked good. No pits, scars or blueing. In fact the pinch was still good. The starting shaft however was blue and the rotostart plate was loose. I'm wondering if that is a symptom or the cause. The actual engine backplate was fine as well as the one way bearing. I'm wondering id the starting shaft (stupid design) was walking and moved the rod while moving? This engine has an external one way and a starting shaft similar to the f series hpi engines. It has a notch to catch the crank instead of the spring loaded pin.

My nephew was running the truck when it happened. Everything was fine. Ran 3 tanks through. He ran it out of fuel the last time and I went to refuel it, when I noticed the roto plate hanging on by one screw. The screws were applied with loctite so that baffeles me.

So the question is did the roto start coming loose allow the starter shaft to wobble digging into the rod or did the rod wobble and dig into the starter shaft, heating the screws on the roto plate causing them to back out???

I did keep the cooloing head. It looks new. The motor was never run hot while I had it. My brother-in-law put a gallon through it before I got it. I did pull it down and change the bearings. Didnt see anything out of the ordinary. I have since put 2 gals on it.
 
Ok dug it out of the trash. I think the black you were talking about was poor lighting. In this pice the only back is right at the rod busing. Got a pic of the piston and sleeve as well.


better pics next post vvvvv
 
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Well got it apart. Few interesting things. Notice the nice brown oil in the case and in the bearings. Theres still some on the crank so it was getting oil. Better pics of the crank and piston too. Now the interesting part, look at the oil hole in the rod. It doesnt go all the way through hmmm... Did it jst get melted over or was it never all the way through in the 1st place and I was luck it lasted as long as it did?













 
Thanks for the additional pix, is pretty weird as to wtf did happen...... I am thinking the oil hole in the rod got packed with debris when the bushing went south..... ya got a puzzler in this one Jim....... I have seen the oil passage plug with oil goo on a few engines but they did sit a long time.... insides do look relatively clean and all so I dunno what may have went on. WEIRD WEIRD
 
I'm thinking something went south with the rotstart/starting shaft. I think something caused it to rub on the crank/rod overheating it. Just a guess, but maybe it wore out and wobbled causing it to jam. I just cant see what else it could be. Oil hole clogged like you said, maybe. It had been a year since I ran it, but used Odonnells. Very oily not ashy though.
 
Another weird thing, usually rods go bad when the p/s wears out allowing it to travel too far oblonging (sp?) the rod bushing. Pinch is still good on this one.
 
Just remembered something. Every time I started it, my radio was glitching like crazy. It never did that before. I blamed the radio. I even ordered a 2.4 to replace it. I wonder if I had a metal on metal rub from the start.
 
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