S50b32 rebuild - Z3M Coupe content

[Lysis]

This silver car came for a visit on Saturday and its owner was so overwhelmed with our garaging facilities he decided to leave it. I must comment on the unmolested condition of this car and its superb overall condition having recorded some 160 000km with a full service history and a sympathetic owner. This truly is an excellent example.

A compression test was done to determine the condition of the motor. The test indicated a very likely possibility of a damaged cylinder head gasket. Cylinders five and six reported the same values which were some 33% less than cylinder one to four.
[1:140, 2:135, 3:140, 4:140, 5:105, 6:100]

Notice here the condition and colour on cylinder five.

The owner decided for work to proceed on the car and the required repairs to be completed.

Tappet cover off, as can be seen this vehicle has been pampered.

Unplugging fuel injection harness.

Notice the difference in colouration of throttle body butterflies 1-4 and 5-6.

 

[Nick]

raise: wow that looks complicated.

 

[Kish2604]

Good attention to detail and workmanship...looking forward to reading more...:thumbs:

 

[Peter@AEW]

Having first hand experience with this car I concur with Lysis in his description of it.

Its owner whom I had the pleasure of meeting is absolutely passionate about the car and strives to keep it in tip top condition.

 

[moranor@axis]

I find the colour difference quite interesting

 

[RAArmstrong]

Wow massive respect!! raise:raise:

 

[AdiS]

I find it interesting with all the comments about how well this car has been looked after, that the head gasket is potentially faulty? What would be the reason for this if the car was not neglected or abused?

 

[444YYY]

I find it interesting with all the comments about how well this car has been looked after, that the head gasket is potentially faulty? What would be the reason for this if the car was not neglected or abused?

+1 also curious....

 

[moranor@axis]

1st theory is it may have overheated at some stage

will let the workshop guys elaborate...

 

[tyu333]

Quick hi-jack:

The butterflies on my M Coupe with 177 000km on the clock all looked like the 5 & 6 in your picture :fencelook:

And after a little bit of TLC, with improved the throttle response

Quick hi-jack over.

 

[ChrisBrand]

Was the drying off of the oil necesarry or is it just because new oil will be added later and you don't want it to mix with old oil?

 

[Rayzor]

Nice write up and excellent workmanship :bravo:

 

[Peter@AEW]

I find it interesting with all the comments about how well this car has been looked after, that the head gasket is potentially faulty? What would be the reason for this if the car was not neglected or abused?

+1 also curious....

The car is not driven regularly and apparently when it was driven to us it was the first time that it was out for some months.

Once the headgasket is examined as well as the head we shall report back.

From photographic evidence posted one can clearly see that the car has not been touched by cowboys.

We could speculate as to teh reasons but would prefer that we get an engineers report prior to feedback here.

 

[Lysis]

Head was stripped off the block so that a more thorough investigation could be undertaken.

A picture of the Vanos bridge with the impact driver used to loosen the Vanos cap screws. These cap screws are ordinarily able to be hand loosened.

The below picture is of the cap screws with silicon sealant clearly in evidence.

Vanos inlet piston screw with either silicon or loctite on the threads. That is a definite no no.

Inlet manifold and Vanos unit removed.

The gear set is in good condition. This can be seen from the blunt gear teeth.

A picture of the inlet tracts, which as can, be seen are spotless.

Cam box has been removed. The S50B32 is a derivative in construction to the M88/S38 motors in as much as the camshafts and cam followers are housed in their own “head”. This has changed in the S54 which uses cam journals and rocker arms and is a one piece construction.

Cylinder one to the left, cylinder six to the extreme right. Gasket looks in order and on first examination there appear to be no cracks on the head. I would be interested to hear your views on why the exhaust valves have an uneven colour.

Here is a picture of the cam box just for interest sake.

The decision was taken with the owner to pull the motor and subject it to a rebuild. A number of reasons informed his decision, amongst which were: excessive piston to bore clearance (twice the TIS specification), low compression on all cylinders especially five and six, bore glazing and bore marking. This indicates a possible overheat at some stage, alternatively a possible incorrect running-in procedure (Chris “Fordkoppie” thanks for highlighting that one).

No more engine.

Owner arrived to collect his car with a vehicle, which apparently never breaks down.

Our apologies for the single leaf on the carpet.

13 years old and no cellulite.

The world’s first lifted Z3 M Coupe. A Smart for reference

 

[tyu333]

Been having lots of sleepless nights about the right silencer being a tad lower than the left. I see its same on this one.

 

[msm]

Lysis - love the attention to detail on your work :thumbs:

 

[Lysis]

Been having lots of sleepless nights about the right silencer being a tad lower than the left. I see its same on this one.

The right silencer is hanging lower than the left because there is currently no mid section on the exhaust.

 

[444YYY]

I like it. Well done Lysis.

Please tell us the reason for the different colour on the exhaust valves

 

[Kyle]

Awesome stuff, looking forward to the progress :thumbs:

 

[Jeremy]

Well done team Axis!!!