Engine & Gearbox

The Engine Bay……..28 year old and needing a good clean and repaint…..

wheels 345 (Medium)


wheels 455

Turret Detail in Black Satin

wheels 454 (Medium)

Inner wing panels in Alpine Weiss (White)…….

wheels 462 (Medium)


Voila !

2.5 Litre Porsche Engine


Looking good, but then………developments then changed and a decision was made to take this engine out !

If a special one off more powerful New Engine was fitted to match the lightweight chassis the car would not only obtain a higher power to weight ration from all the total weight reductions (Over 250Kg !) but also increase further with more engine power..

Components were sourced, and tuned from across the Altlantic ocean from the Porsche Racing Specialist Lindsey Racing (USA):

– 3.0 944 S2 Litre Block  (Lightly Honed)

wheels 1000287


– 2.5 944 Turbo Crank 2.9kg has been machined off (knife edged) and polished, the original crank design is at the bottom

wheels 1000300


– 968 3.0 Litre lightweight Forged Conrod’s as opposed to the cars original heavier cast rods

wheels 1000320


New Lightweight Forged German Manufactured Wossner Pistons & Rings with a higher Compression ratio. (10:9:1)

wheels 1000307


Orignal cast 2.5 Litre piston on the left…..New Forged on the right…….

wheels 1000323

You can see how much slimmer the lighter forged Piston is, also the forged rod….

wheels 1000324

wheels 1000322


– 2.5 Litre 8 valve Cylinder head before it was sent to Lindsey Racing (USA) for a full rebuild and gas flow work on the Inlets which yields a improvement of 28% more CFM airflow

wheels 662

And after………

wheels 1000289

wheels 1000290

wheels 1000296

wheels 1000295

Widefire Head Gasket

wheels 1000318

The capacity of this “Bitzer” configuration is 2707cc

Each piston capacity is just over 675cc x4 cylinders with 2 valves per cylinder…..


The original Steel Flywheel……….@ 7KG

wheels 290 (Medium)


Machined off 1KG to 6KG

wheels 552 (Medium)

But an even lighter Aluminium Spec (USA) item was then decided on….

Which only weighs 2.7 Kg !

wheels 1000614


New Engine Build

Many parts and components were required to completely build the new engine..

wheels 1000437

The car’s original engine was stripped……

wheels 1000487

wheels 1000490

The oil Pump, And Balance shaft housings were stripped and powder coated……

wheels 1000483


On the left is a modified cut down & drilled (Lighter) Alternator bracket which will carry a 3kg Alternator and not a 6kG version as the original bracket did on the right!

wheels 1000473


The original Camshaft was identified as there are 2 versions…….

wheels 1000475 (Medium)

And a new special profile was selected and made in the USA by Web Camshafts from California.


wheels 1000616


The Lobes profile of the new Cam (On the left below) are different, with more duration

between the inlet and exhaust valve’s opening…..

Which with mapping will increase engine Torque and BHP,

especially in the mid RPM range….

wheels 1000623

Adjustable Cam Pulley (Lindsey Racing USA)

wheels 1000605 (Medium)


Summit Prep (Preston Uk) built the Engine:

wheels 1000740


Summit Prep Engine 3


Summit Prep Engine 2


Summit Prep Engine 1


Engine 0114


The Engines Colour scheme is Silver block / head and ancillaries… with a vibrant

blue / purple Cambox and Inlet Manifold…

This is a mock up with an experimental cambox, the actual Inlet being used, placed

on to the old engine…..

wheels 1000443 (Medium)


Another experiment (R&D) is to see what RED “Porsche” letters look like, so this Cambox is the one from the original engine, which has been powder coated in a RED…

wheels 1000479

All the surfaces have been flattened down by hand to achieve a billard smooth finish,

The next stage is to paint the entire component in the Blue / Purple Colour

with a Special High temp (200 degree) paint blended at thewheelrestorer……

Then when this is dry……I will use a light grade of sanding paper to remove the red

from the top Logo area only, this should reveal a RED Colour, which when Gloss

Powder Lacquered should be looking good!

wheels 1000481

The bottom and ends have been masked using a special high temp tape…….

wheels 1000478

After preparation all by hand, flatting down all surfaces……the Cambox was painted

with a High temp Metallic Blue

wheels 1000494

Once baked and cooled the hardest bit was to remove the blue paint with a palm

sander revealing the red underneath on the Logo….

The finished article…….

wheels 1000498

Assembly progressing……..




The Engine was installed (Feb 2016)

IMG_6093 (Medium)


Modified and lightened original Inlet Manifold

I Cut off the swan neck, and made the throttle body entry more straight…….

wheels 1000009 (Medium)

Exactly the same Inlet manifolds……

Original on the left,………. modded on the right ( lightened of course!)

wheels 1000049 (Medium)

Powdercoated in Primer ready for a colour….

wheels 1000106 (Medium)

This inlet was then sent to the USA to a company called Kennametal

They have a service called “Extrude Honing” which involves an abrasive putty which

is forced under pressure through the inlet manifold, this cleans up the rough casting

walls and vastly improves the airflow by up to 25%

An example of the process………Before with the rough casting surface evident

Extrude stock

And After the process

Extrude done


Here’s the Inlet back from the USA………

wheels 1000278

And a shot of the main throttle inlet looking nice and smooth………

wheels 1000286



wheels 1000344


Standard Throttle body and Bosch TPS,

An extension tube has been made to give the Inlet a big Plenum volume for the incoming air to “settle” before it’s distributed  to the 4 Inlet Tracts

Powdercoated to suit the Blue Inlet and Black Throttle body………….

wheels 1000770


The Inlet needs some thought and designing, the objective is to create a straight line

of flow for each component : Air Filter, AFM, Throttle body……

wheels 1000792

wheels 66731147



Here’s a sketch of what was intended Inlet system with an ITG Filter located behind the front badge panel



But to get the Engine running first a quicker system has been installed.


Inlet1 (Medium)


And before the Rolling road tune, i boxed in the Filter with some Zircotec specific HEat shielding


wheels 66731585 (Medium)


Modified lighter Balance shafts are were fitted, (with one of the counter balance weights cut off) sourced from Broadfoot Racing USA


Race_Shafts_7 (Medium)




The original is aluminium & plastic but………….it’s too heavy !

wheels 640 (Medium)


Or rather a lighter version is available……..approx. 1.5kg lighter

Winner Racing (China)

Here coated in a VHT Ceramic Grey

wheels 66731399 (Medium)


The original fan assembly is very heavy (3.5kg)

wheels 641 (Medium)

I’ve installed a lighter Spal version around 1.5kg

wheels 66731417 (Medium)



The original Alternator was a lardy 6kg…..!

wheels 624 (Medium)

A Brise lightweight (3kg) has been fitted.


Brise alternator

wheels 1000764

The original Bosch starter motor is not too heavy and will be used…

wheels 626 (Medium)


Starter Motor

The original was used for a few months after the install but was struggling to turn over, either due

to the high compression or it was on it’s way out!


So I replaced it with a GEAR Reduction WOSP Unit.

wheels 66731844 (Medium)


Transaxle Gearbox

To be checked, rebuild and fitted with a LSD

wheels 680

Wavetrac (USA) unit Supplier By EMC Motorsport (Birmingham)


wheels 1000586 (Medium)


Summit Preparation stripped the gearbox and are rebuilding it with the new LSD




New Gearshift and rear linkage

wheels 130 (Medium)


Then I found the gearstick was too far away from my low bucket seating position and also

the throw was too long and at a full arm’s stretch, so a Modified “Dog leg” gearshaft

was designed and made which brought it 2″ nearer towards the steering wheel and also

2″ further back.

wheels 66732037 (Medium)


Also to be used with a Only944 Short shift rear linkage

wheels 66732047 (Medium)


Dogleg shift rod fitted, and the test drive was a success, the new position is far easier to

get hold of and the knob also better control than the original bulky stem / knob


wheels 66732056 (Medium)


the original rear linkage came off easy enough but the stay bar sheared it’s bolt

in the top of the gearbox!

wheels 66732068 (Medium)

So without removing the gearbox to drill it out! I had to design a bracket and put the

stay on the other side.

wheels 66732076 (Medium)


Revised version II with a Nylon Gearknob and extra gusset for strength

wheels 66732180crop (2) (Medium)



Powdercoated Driveshafts with New CV Joints

wheels 66731612 (Medium)



Original Engine Tray stripped / coated & fitted:

wheels 66731723 (Small)


The car was Running on July 13 2016, and then after several more jobs I collected it on Friday 5th August,

Over that weekend the car & Engine were “Run In” and a Rolling Road session took place 9th August

By Wayne Schofield (Chip Wizards)

Chipwiz0255[1] (Medium)

The results were better than anticipated, after 8 hours “Live” mapping a final figure of 205 bhp & 205 Ft Lbs of Torque was achieved…..

Click on the “ChipWiz” & “Tech Spec” underlined links below to view the actual Rolling Road Graph and a specification sheet and the car’s final weight..

which is 1010 Kg ! …………..but this will be reduced further, I want a number beginning with 9…!


TEch Spec 924srr27L