Big end failed

[Vintage man]

Today driving my 1600 tp bus it last all power then locked up, stripped the engine and found that only one big end ran a bearing. The bearing pushed out on the sidesWhy would the happen and could over heating have caused it. What would go first if it did over heat. Thanks in advance as it is really bugging me.Could overheating cause this without damaging the piston and barrels.

[Tony Z]

anything could have caused it, wrong oil, dirty oil, old oil, incorrect machining clearances, wrong bolt torque, knocking, wrong spark plugs, burning exhaust valve, wrong timing, not serviced often enough, broken down oil, petrol in oil, too low oil level, too high oil level, air in oil, oil without anti-foaming additives, over-revving, worn out block, bad luck...

overheating might have roasted the oil and caused this. Overheating might have been causing detonation and the first thing to give in was the big end

[retrovan]

You will have to give more detail on your engine.

Was it newly built, was it very old, did it have all the plates around the engine, was it serviced recently

Maybe a picture of the engine in the car before it happened would also help.

All these would change the prognosis.

Herman.

[Dawie]

Did the oil pressure light come on before this happened?

[Vintage man]

Will get some pictures ,no oil light but since the motor was fitted even after fresh oil and serviced the oil light came on fligering when hot at idle.It was a rebuilt engine.

[Terry Phillips]

Who done the motor and how long ago was it done.

[Vintage man]

Not sure Terry but was standing for about 4 years before I fitted it.

[Tony Z]

you've got compression leaks everywhere

[Vintage man]

Thanks Tony ,I did notice that the one side was hotter than the other side as the paint on the silencer was off compared to the right side.The exhaust also had a bit of leakage,Would it be a vacume leak that could cause this as the both sides would have been the same then,

When you say compression leaks , is that heads ,valves.

[Tony Z]

yours are barrels to heads
bad machining and/or bad fitting is likely the cause

[Vintage man]

[Vintage man]

Some pictures added and I see the conrod that seized is dry as the rest still wet with oil.
Cause ?

[retrovan]

It would seam as if you have a blocked oil port and or bad spring in your pressure release by-pass.

Some guys when rebuilding an engine, forget to flush the oil cooler and the old metal shavings block the oil passages when 1st starting the re-build motor

Please see these items and make sure where your problem is before making the same mistake again.

sorry that it happened, good luck

Herman

[calooker]

Some pictures added and I see the conrod that seized is dry as the rest still wet with oil.
Cause ?

Its dry because it got so hot it burned all the oil off.

[calooker]

Will get some pictures ,no oil light but since the motor was fitted even after fresh oil and serviced the oil light came on fligering when hot at idle.It was a rebuilt engine.

If the motor blew and the light never came on tells me that you had a blockage in the oil passages as little or no oil got to the big end.
This leads to the rod end getting super hot to the point it will melt / fuse metals.