ej257
03 December 2006, 09:21 PM
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ej257
my ej257 started knockin so i stopped to find the engine had seized took it home to find the engine turns back and forth about a third of a turn.
timming belt is ok any other suggestions before i pull it apart?
timming belt is ok any other suggestions before i pull it apart?
04 December 2006, 08:21 AM
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Oh Dear
Originally Posted by simbo
my ej257 started knockin so i stopped to find the engine had seized took it home to find the engine turns back and forth about a third of a turn.
timming belt is ok any other suggestions before i pull it apart?
timming belt is ok any other suggestions before i pull it apart?
---john---
04 December 2006, 12:46 PM
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Originally Posted by John Stevenson
I would imagine you will be buying a new crank and rod(s), set of main & big end shells, gasket set, oil pump and oil.
---john---
---john---
04 December 2006, 06:49 PM
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Really not worth the risk of reusing the oil pump unless on tear down it's completely undamaged. Replace the Modine without question, and the components being re-used from engine will need a very very thorough clean
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30 May 2007, 12:20 AM
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30 May 2007, 09:52 PM
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Looking at that disaster, my opinion would be that you probably had a bent valve [ or two ] when it all went together. The valve head has eventually snapped off and then mechanical intercourse is inevitable.
Impreza valves are very thin stemmed and the only way that you can be sure of them EVER, is take them out of the heads and spin them in a drill chuck. Careful checking will show the bent ones.
It is very rare that when we rebuild engines, we manage to use all the original valves, there is always one or two that are bent.
Once bent, the valve straightens into the seating by the force of the spring and then releases as soon as it is off its seat. You all know what happens when a piece of metal is continually bent and then straightened. A hollow valve stem only lasts so long.
Just my thoughts based on what we see day to day.
Good luck with the repair, that is a comprehrensive failure. Call me if we can help with any parts.
David APi
Impreza valves are very thin stemmed and the only way that you can be sure of them EVER, is take them out of the heads and spin them in a drill chuck. Careful checking will show the bent ones.
It is very rare that when we rebuild engines, we manage to use all the original valves, there is always one or two that are bent.
Once bent, the valve straightens into the seating by the force of the spring and then releases as soon as it is off its seat. You all know what happens when a piece of metal is continually bent and then straightened. A hollow valve stem only lasts so long.
Just my thoughts based on what we see day to day.
Good luck with the repair, that is a comprehrensive failure. Call me if we can help with any parts.
David APi
31 May 2007, 09:06 AM
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Using the data we collect and our own experience of the mayhem we see inside the engines that come here. Usually at a rate of a minimum of 12 a month, we believe:
When the big end fails the shell bearing spins around within the rod and eventually disappears. That leaves the con rod big end loose to the amount of the thickness of two big end shells on the crank About 5 mm.
At the top of the stroke the piston is able to travel up and hit the head. [It has gained 2.5mm of stroke ] Because of the delay of the crank pulling the rod down again [ it has to take up the 2.5 mm of slack before it moves] the valves are opening and 'help' the piston on its way down again.
Ditto the exhaust valve is still shutting when the piston is on its way to the top.
We rarely find 4 bent valves mostly 2.
What worries me is that we almost never find less than 2 valves bent on the damaged cylinder. Other ' customers' of engine parts from us tell us that the valves in their engine are fine................ Have they taken them out and looked? 'No need, I can see they are straight '
David
When the big end fails the shell bearing spins around within the rod and eventually disappears. That leaves the con rod big end loose to the amount of the thickness of two big end shells on the crank About 5 mm.
At the top of the stroke the piston is able to travel up and hit the head. [It has gained 2.5mm of stroke ] Because of the delay of the crank pulling the rod down again [ it has to take up the 2.5 mm of slack before it moves] the valves are opening and 'help' the piston on its way down again.
Ditto the exhaust valve is still shutting when the piston is on its way to the top.
We rarely find 4 bent valves mostly 2.
What worries me is that we almost never find less than 2 valves bent on the damaged cylinder. Other ' customers' of engine parts from us tell us that the valves in their engine are fine................ Have they taken them out and looked? 'No need, I can see they are straight '
David
31 May 2007, 09:28 AM
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For the time it takes and bearing in mind:
1/ the consequences of a valve head dropping off
2/ potential poor performance
3/ how labour intensive a Subaru engine is to remove, strip and fix.
It makes most sense to take them out and spin them up to be sure.
Obviously, the consequences for one of our engines to wreck itself are far more serious than someone who makes a mistake whilst building their own engine. BUT in general terms if you are spending heaps putting together a good engine, no stone should be left unturned.
Rather like big end bolts; use 'em once, bin 'em and be sure.
David APi
1/ the consequences of a valve head dropping off
2/ potential poor performance
3/ how labour intensive a Subaru engine is to remove, strip and fix.
It makes most sense to take them out and spin them up to be sure.
Obviously, the consequences for one of our engines to wreck itself are far more serious than someone who makes a mistake whilst building their own engine. BUT in general terms if you are spending heaps putting together a good engine, no stone should be left unturned.
Rather like big end bolts; use 'em once, bin 'em and be sure.
David APi
31 May 2007, 06:42 PM
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Looking at that disaster, my opinion would be that you probably had a bent valve [ or two ] when it all went together. The valve head has eventually snapped off and then mechanical intercourse is inevitable.
Impreza valves are very thin stemmed and the only way that you can be sure of them EVER, is take them out of the heads and spin them in a drill chuck. Careful checking will show the bent ones.
It is very rare that when we rebuild engines, we manage to use all the original valves, there is always one or two that are bent.
Once bent, the valve straightens into the seating by the force of the spring and then releases as soon as it is off its seat. You all know what happens when a piece of metal is continually bent and then straightened. A hollow valve stem only lasts so long.
Just my thoughts based on what we see day to day.
Good luck with the repair, that is a comprehrensive failure. Call me if we can help with any parts.
David APi
Impreza valves are very thin stemmed and the only way that you can be sure of them EVER, is take them out of the heads and spin them in a drill chuck. Careful checking will show the bent ones.
It is very rare that when we rebuild engines, we manage to use all the original valves, there is always one or two that are bent.
Once bent, the valve straightens into the seating by the force of the spring and then releases as soon as it is off its seat. You all know what happens when a piece of metal is continually bent and then straightened. A hollow valve stem only lasts so long.
Just my thoughts based on what we see day to day.
Good luck with the repair, that is a comprehrensive failure. Call me if we can help with any parts.
David APi
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