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ACK [piston]

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austin10_4

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Just thought i'd take the Jag out for a little spin tonight but just as i was breaking the 90mph trying to get to 100 atleast /bcforum/images/%%GRAEMLIN_URL%%/frown.gif BANG lost compression, banging all over the place black smoke you name it it was not a pretty site. So, anyway i thought id bring it home and see the damage, turns out i snapped a piston conrod! Any ideas why this should happen? Not under any strain or anything, only thing i have noticed for a while now, is going from second to third gear, it makes the engine cough and gurgle for a few seconds when it normally didnt :| Anyway, just thought id give you all something to think about!
 
At 90 MPH under a load IF the con rod broke consider yourself lucky it didn`t come through the side of the block. And even if it didn`t come through the side of the block and it DID break, there will most assuridly be "Other" damage. Possibly the camshaft or even the crankshaft, Hopefuly Not, But I wouldn`t count on it.
 
coldplugs- i've had the head off the engine, and using my special piston push/pull clamps, i pulled the piston right out, and only half the rod came out!
 
Bet that cylinder's trashed! & you are lucky the rest of the rod didn't go through the block!

That usually happens if there's a serious oiling failure - bad pump possibly?
 
austin10_4 said:
using my special piston push/pull clamps, i pulled the piston right out
Click to expand...

I would be interested to see a pic of this "Special" tool. Is it home made? Can you post something or send me a pic in P.M.? Might be something I would like to add to my collection of "Special" tools.
Kerry
 
""""""interested to see a pic of this "Special" tool""""""

probably an Aluminum magnet.


""""""""turns out i snapped a piston conrod! """"""

Even good English steel has a finite life.
 
tony barnhill said:
Bet that cylinder's trashed! & you are lucky the rest of the rod didn't go through the block!

That usually happens if there's a serious oiling failure - bad pump possibly?
Click to expand...

Oil pump failure won't cause a connecting rod to fail, it'll cause
a camshaft to fail first, seizing in the head, then the open valves
hit the piston and break off the stems, then the pistons come back up
the bore tnd try to push the valve heads through the head, but cant
because the piston fails before the head...

AMHIKTBOT...
BTDTBT...

SteveL
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]AMHIKTBOT...
BTDTBT...[/QUOTE]

??

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Oil pump failure won't cause a connecting rod to fail, it'll cause a camshaft to fail first, seizing in the head, then the open valves hit the piston and break off the stems, then the pistons come back up the bore tnd try to push the valve heads through the head, but cant because the piston fails before the head...[/QUOTE]

So, all that happened because the oil pump failed? & the result was a broken rod? Or a piston with a big hole in it?
 
If the oil pump failed, there will be a LOT more damage than just one broken connecting rod.
 
Gah. That means a complete disassembly/rebuild. Hope the block was spared: those don't grow on trees. At least you're in the right part of the planet to more easily find bits. I did up a 3.8 in a client's 150 a few years back and had an awkward time finding some of the parts. They're "around" but it was: some from here, some from there. Like an Easter egg hunt.
 
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