[Nickhey71]

Think I've got photos to work with ipad.


These are taken as engine was being rebuilt:

               
These taken recently with bores cope and photographed with iPhone, hence poor quality:                

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[Nickhey71]

Too good to be true, nice shiny 'rebuilt' engine....

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[Ab54666]

Who built the engine Nick?

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[Nickhey71]

Hi

Don't really want to name or shame as there could be an unforseeable reason.

They are a well known UK specialist in the 968 and its engines , which is why I chose them originally.


However I think the main candidates are:

- incorrect or poorly gapped rings

- bores not reworked to allow rings to bed in

- fuel wash

- not using a specific break-in oil


I do recall a delay while they were "waiting for the correct rings to arrive".

I didn't use a break in oil, but would have done if advised.

The fuel wash factor is on the list because the ECU had a race chip which I assume increases the fuel delivery rate. It did not occur to me to put the standard chip back in at the time, because as can be seen the bores were fine following around 18 months of using the race chip.


Should get the replacement engine back in the next week, following a light refresh (belts, seals, chain/pads etc)

Have decided to leave the internals alone, following a satisfactory borescope, sump/cam cover off inspection.


Fingers crossed it doesn't immediately drop a valve or throw a rod, lol!

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[Ab54666]

Sorry, I wasn't thinking of a 'shame' part, just interested to now, feel free to PM me.

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[PorscheG96]

However I think the main candidates are:

- incorrect or poorly gapped rings

- bores not reworked to allow rings to bed in

- fuel wash

- not using a specific break-in oil


I do recall a delay while they were "waiting for the correct rings to arrive".

I didn't use a break in oil, but would have done if advised.

The fuel wash factor is on the list because the ECU had a race chip which I assume increases the fuel delivery rate. It did not occur to me to put the standard chip back in at the time, because as can be seen the bores were fine following around 18 months of using the race chip.

 

Sounds very similar to my current dilemma.  I recently bought a 968 race engine from a wrecked car that was built by a premier engine builder.  Granted there are many nice parts that I'm happy with and plan to use on my engine build in the future, I decided to perform a complete teardown to assess the engine's condition.  Everything looks fresh from gaskets and seals to valve train and bearings, however, the bores are seriously scored - even worse than yours, actually.

 

I share the same theories as you with regard to root cause, ie. fuel wash due to poor tuning [larger injectors, adjustable FPR and custom DME chip], and spotty bottom-end tolerances.  Would you mind sharing your ring gap and bearing measurements?  On my engine, the measurements were at the extreme end of allowable tolerances...tight ring gap, loose rod bearings IIRC.  Will dig up the numbers.

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[Nickhey71]

Hi porscheG96, sorry for the slow response,


Yes I'm planning to have a post mortem carried out, but that will be sometime later in the year.

I'll make sure they take the measurements of all critical components and check against factory tolerances and your data.


Another suspect identified is the injectors. Talking to the guys who are preparing the replacement engine, they say it's a known issue that injectors can seize partially or even fully open and dump loads of fuel into the cylinders.

Hence the need to get them serviced!


Everything will be documented on here, once that process is finished.

Hope that will add something to the knowledge base....


Cheers

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