Well doesn't time fly when you are busy doing other work , I took my 1986 S3 5.0L 32v off the road 5+ years ago , 270,000 + kms on the odometer , but with lots of city/suburban driving in its first 15+ years of life & with thousands of hours engine running stopped in traffic the real kms traveled is much higher if it kept moving & not stopped . I was concerned about the crumbling state of the old head gaskets , plus after all those years / decades the entire engine bay was in a poor state , be it old crumbling wiring harnesses & oil leaks from everywhere & the old magnesium inlet manifolds were a paint crumbling mess , so I just parked it at work with the idea of taking the engine out of it when we were not so busy at working on customers Porsche's If it wasn't for Sean Buchanan, I would never had gotten around to doing what we wanted to do & the final result is simply amazing , far far better than I could ever hope for & it made for lots of fascinating before and after photos , I was happy to do just the engine and engine bay , but Sean had other ideas , much much further . This car sucked up more late evenings & Saturday afternoons than I first realized , month after month , year after year , not every week , but when we could , it was a labour of love.

First of all ( years ago ) engine out , mount on engine stand , dismantle all the engine external components and as per normal there were kilos of hidden dirt mixed with oil in more nooks and crannies & thick grime everywhere , hours & hours of cleaning fun , every external bolt & nut from engine external components , be it brackets , alternator bolts , sub-frame bolts & engine external bolts were cleaned & measured & catalogued , because along with hundreds of other small & medium sized steel brackets all these bits were going into our tumbler to be completely cleaned of rust and surface corrosion and a uniform final finish so we could send ( boxes ) of these and other steel parts to be sent to be re- yellow gold zinc plated back to the original look
There was one thing I wanted to do to this engine & that was to discard the original S3 quad cam heads & install 928S4 cylinder heads , but I want to retain the beautiful S3 inlet manifolds , not so easy , buy I already knew that , now the Australian delivered 1986 ( only ) 928S3 5.0L 32v engine was a lower compression ratio as compared to the 1986 USA version , USA was 10.0: 1 , where as the Australian 5.0L was 9.3:1 compression , that was because ( back in 1986 ) we in Australia a very poor quality low octane unleaded fuel ( petrol ) with lot & lots of sulphur ( rotten egg gas out of exhaust pipes of all unleaded cars back in the late 1980's ) and the 1986 S3 did not have any knock sensor control , the 1986 951 did , but the 928 had to wait until the next year for that ( 1987 > ) and the 911 didn't get it until 1990 ( 964 ) .

The 1986 S3 ( Aus M28/45/46 ) had special 100mm dia pistons that had a concave dish in the middle to lower the compression ratio to the 9.3:1 , very similar to the Australian 1985 928S 4.7L , 2v 98mm pistons with the concave dish to lower the compression on that engine .Note } the 928S3 quad cam cylinder head combustion chamber had a volume of 56.5cc , where as the 928S4 heads had a volume of 42cc , so with the thickness of the head gasket ( crushed ) and the bore size of the head gasket fire ring ( all makes a difference )& the volume of the cylinder at BDC & the piston deck clearance calculated the theoretical static compression ratio of installing S4 heads on the M28/45/46 engine should result in a 10.8 : 1 or 10.9:1 static compression ratio = Nice on 98 premium unleaded But before all that , we had to make sure the condition of the original pistons & cylinders were OK .

So over the next month or two ( years ago ) the engine cam apart & it was just fantastic , the original pistons & cylinders had zero wear , the pistons were perfect , even the piston rings were unworn ( perfect ring gaps ), the con-rod bearings were perfect & the main bearings looked amazing , the thrust bearing was unmarked , it had zero wear & yes this engine was a very lucky engine because it never ever from new had anything other than 20w-50 engine oil in it ( I have known and serviced this car from new ) , that part of the reason I purchased this particular 928S all those years ago , but this is an auto trans car ( basically its a 928S4 ) but it never every wore its engine thrust bearings , I wonder why ? Answer = it never ever suffered the fate of having low oil film strength 10w-40 or much worse the very low oil film strength 5w-40 oil viscosities that humans stupidly put in last century Porsches early this century

The standard 100mm alusil bores were fantastic , no lip and no scratches ( fantastic oil film strength ) and after cleaning , on reassembly of the engine we even reused the main bearings & pistons , so at that point the S4 heads were going to be used ( reconditioned 2nd hand ones we had in stock ) , I even went so far as to calculate the S4 heads ( machined ) and genuine Porsche 928S4 thicker head gaskets to keep the compression ratio were I wanted it . The S3 quad cam engine used head studs , but the 928S4 runs head bolts , so I purchased the correct sized head bolts from Porsche to match the version of the S4 heads , naturally that means the removal of the old head studs from the crankcase New timing chains & 928S4 tensioners & nylon slipper guides.
Now the real interesting part is the shape of the inlet ports in the 928S4 heads , they are oval but 90 deg out in comparison to the very unusual oval ports in the 928S3 quad cam heads , now that would not be an issue if you were converting to 928S4 manifolds , but I didn't want that , I wanted the look of the more complex S3 manifolds , so that took lots & lots of labour porting the manifolds to match up ( fun fun fun ) , but I wanted perfection & time was on my side Everything in the engine bay that was once yellow chromate ( be it bonnet hinges , accelerator linkages , bonnet catches ( hundreds of little parts ) are back to their original look in yellow gold zinc plating & I am really fussy with the look , the handy man kits you can buy to re plate these parts always look to gold or too fake , I wanted the exact look The magnesium inlet manifolds & the magnesium (twin cam) cam covers were sent away to be stripped & redone back to original silver appearance coatings with the inside of the manifolds & (twin can )cam covers in DF2 non wet-able matrix coatings & all the through bolts & cup washers were re- yellow gold zinc platedNew re manufactured engine wiring harnesses & new 4 pintel hole Bosh injectors , we use these only in the M28 45/46 Our new custom 120 amp Alternator , plus heaps more , far too much to list .

Meanwhile Sean was dismantling the front & rear suspension ( completely ) including the auto transmission ( transaxle ) & removal of the Torque Tube & Sean overhauled the T Tube & medium blasted all the rear suspension arms & he entire alloy sub-frame ( all the bolts & washers were re-yellow gold zinc plated ) , Sean even polished the original exhaust system ( type of stainless ) , but it does have a custom rear muffler delete in stainless Rebuilt front suspension upper & lower control arms ( Roger & 928sRus supplied ) Parallel Flow A/C condenser & custom new radial blade A/C electric fan incorporated into the existing shroud , which took a lot of extra labour , but its for a certain look .

The wheels I had re anodized 14 or 15 or so years ago , but even better they are the wheels I always admired , they are the exact wheels on a silver Porsche 928S in the Porsche museum & they were standard fitment on the 1988 & 1989 Porsche 944 Turbo S ( Fuchs Forged & anodised in silver ) , meaning they at first glance to be the wheels from the 1989 928GT , but they are not , well not exactly The rear wheels are from the 928 Club Sport 1987 prototype & 1988 Club sport were non tyre pressure sensor CS Fuchs wheels , meaning no holes in them & they are 16" X 9 " & yes they must have the hard to get these days 245 / 45 / 16 tyres .

The front wheels are unique to the 951 Turbo S & the 928S in the Porsche museum , 7" X 16" with ET 65mm , didn't I spend a small fortune years ago buying these wheels from an Australia delivered 951 Turbo S with NO salt corrosion & then spending another bigger fortune getting them repaired & re-anodized & worth every cent & because the ET is perfect the steering feel is perfect & now as of the last two weeks my 928S is re registered & insured & I have been driving her , boy go boy it drives fantastic , its interesting , with the increased compression does exactly what I expected , it goes better than extremely well with the added advantage of extra engine braking even with an auto trans , , the Auto box is just fantastic as is well suited to what I like , the performance is as expected = fantastic , very much like a 928GTS only a tad quicker ( I have a GTS as well , which will start restoring soon ) This 928S is a real life test bed on what's achievable in 2018 & I must say its quite impressive , its that good I can not stop driving it Years in the making

Some photos below

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