<VV> VirtualVairs Digest, Vol 38, Issue 105

[djtcz at comcast.net]

snipped and bottom posted 

-------------- Original message -------------- 
> Subject: Re: follow up to no compression in cylinder #3 - found 
> the problem! 
> To: 
> Message-ID: <000001c892b5$0663aa70$0201a8c0 at HEBRINK> 
> Content-Type: text/plain; charset="windows-1250" 
> 
> Many thanks to all who offered help with my question regarding no 
> compression in cylinder #3. I would especially like to acknowledge Michael, 
> Bill, Harry, James, JR, Jack, Russell Ron and Clark for their specific help 
> and recommendations. Lots of good suggestions, but in the end, it turns out 
> to be something completely different! 
> 
> I hope you will be able to view the pictures I took of the culprit. I would 
> describe this as catastrophic damage to the rod, rod cap and bearing. 
> Probably did a number on my crankshaft too. 
> 
> Still interested in hearing from anyone that wants to lob in ideas, 
> suggestions, amusing anecdotes or words of encouragement. 
> 
> Thanks again, 
> Jedd 
> 
> 

I think it may have run out of oil.

Looks like both rod bolts are still intact.  The break looks to have originated from the bolt seat in the cap.  The worn and rounded condition of the edges of the rod big end bore suggest it was acting like a bearing for a while, which usually happens when the rod bearing inserts are long gone. Like this one.
http://lh3.google.com/John.Schwaner/Rw4_-3kZ3zI/AAAAAAAAAhs/B8yy0wF3UHg/lycomingBearing.jpg?imgmax=400

http://www.obd-onboarddiagnostics.com/images/Dodge/bearings.jpg

The rod bearings wear real thin, real quick when there is more heat generated than the oil can flush away.
http://www.turbocelica.com/TheShuttle/Engine/Images/spunbearing/spunrb4.jpg

The burned dark color of the entire big end suggests plenty of heat, as  generated by failing bearings.
http://lh6.google.com/John.Schwaner/Rw4-jnkZ3lI/AAAAAAAAAfs/IngWmLvy19o/lycomingBearing1.jpg

http://lh5.google.com/John.Schwaner/Rw4-xXkZ3pI/AAAAAAAAAgM/kYomFK-0_KA/lycoming_rod_cap.jpg?imgmax=400

Sometimes the bearing failure is caught before the bearing finishes welding itself to the crank.
http://memimage.cardomain.net/member_images/8/web/2216000-2216999/2216807_44_full.jpg

If it really is a structural rod failure things stay relatively clean during the mayhem.
http://images.hotrod.com/incoming/hrdp_0604_10_z+ford_302_engine_parts_failure+connecting_rod.jpg

Dan Timberlake 
Westford, Massachusetts, USA