The ideal 993 engine

M64 crankcase, sound bearing bores and case halves

There is no aftermarket crankcase for this engine and there is unlikely ever to be one. That inverts the usual logic of a build: the donor engine is worth buying for its case, and a seized or holed engine with intact main bearing bores is a better starting point than a running one, because everything else here gets replaced anyway. For a Turbo the case is the M64/60. Albert Motorsport and Freisinger both trade in M64 cases and cores. Note that the 102.7 mm bore this build uses may require the case to be machined, so a sound case is the starting point of a machining job rather than the end of the search.

Known sources: Albert Motorsport / 911race , Freisinger Motorsport

Billet steel, 80.4 mm stroke

The 993 3.6 runs 100 mm × 76.4 mm. Swindon’s GT3+ crank takes the stroke to 80.4 mm, which with the matching 102.7 mm bore gives 3,996 cc — the arithmetic behind the 4.0 figure. It is billet machined in EN40B, a nitriding steel, and described as an evolution of the OEM GT3 4.0 crankshaft with more rigidity for higher rpm. Steel is the right answer here and this one is steel; a light-alloy crankshaft solves a problem nobody has. Swindon ask to be consulted on rod requirements if their own rods are not used, which is a fair warning: crank, rods and pistons are one dimensional set, not three shopping decisions.

GT3+ 4.0 Crankshaft, 80.4 mm Stroke · Swindon Powertrain £6,000 as of 2026-08-18

Titanium, steel bolts

Rods are where titanium genuinely earns its place: the mass is reciprocating, so every gram removed reduces the load the crank and bearings see at every revolution, and the benefit compounds with rpm. Swindon’s set is dimensioned for the GT3+ crank and the 102.7 mm pistons, which is the reason to prefer it over a generic titanium rod here. Grade, mass and bolt specification are not published; the bolts stay steel in any case. A titanium rod with titanium bolts is a rod that comes apart.

Titanium Connecting Rod Set, 24V 4.0 · Swindon Powertrain £10,000 as of 2026-08-18

1 alternative

• Titanium Connecting Rods · Pankl Racing Systems

102.7 mm bore, pistons with matched liners

Swindon supply the pistons with Capricorn 102.7 mm barrels, matched to their crank and heads. LN’s Nickies are the alternative worth knowing about: billet aluminium cylinders with a nickel-silicon-carbide bore, which conducts heat out of the cylinder far better than the original — the constraint that matters most on an air-cooled engine under boost. The catalogued Nickies set is a 3.6 naturally aspirated package, so it belongs to the other version of this build.

24V Piston and Liner Set, 102.7 mm Bore · Swindon Powertrain £6,000 as of 2026-08-18

4 alternatives

• 24V Piston Set, 102.7 mm Bore · Swindon Powertrain · £3,600
• Nickies Billet Aluminium Cylinders, air-cooled 911 · LN Engineering
• Nickies Cylinders 105.029 mm with 12.5:1 JE Piston Set, 911 3.6 · LN Engineering
• Mahle Motorsports Piston and Cylinder Sets, Porsche · MAHLE GmbH

Original crankcases may need machining to take the 102.7 mm bore. Piston alloy and compression ratio are not published and are not guessed at here.

Four valves per cylinder, retrofit to standard M64

The M64's two-valve head is the ceiling on the whole engine. Swindon's 24-valve kit lifts it without moving anything else: the standard crankcase, cam drive, lubrication system and exhaust all carry over, and it accepts 95 to 102.7 mm bores. Flow is 40% better on the inlet and 66% better on the exhaust than a standard 993, the valvetrain is engineered to 12,000 rpm, and the whole set is 3.5 kg lighter than the heads it replaces. Better exhaust flow matters twice over on a turbo engine, because it buys the same power at less boost and less backpressure. Past 100 sold, so this is a production part, not a promise.

24-Valve Cylinder Head Kit, M64 (964 / 993) · Swindon Powertrain £31,448 as of 2026-08-18

Steel, profile to suit boost

The Swindon kit includes its own camshafts, shafts and finger followers. The catalogued alternatives are two-valve profiles and are listed here for the naturally aspirated version of this build, not the 24-valve one. Camshafts stay steel in every case.

Porsche 993 Euro RS Profile New Billet Camshaft Set For Hydraulic Rockers (ENG 05 562) · Web Camshafts US$1,305 as of 2026-08-17

1 alternative

• Camshaft Set, 911 3.2 / 964 · Schrick

Titanium valves, steel springs

Titanium inlet and exhaust valves, springs, caps, collets and shims come with the Swindon kit. For a two-valve engine the catalogued spring and titanium retainer set does the same job in miniature. Springs themselves stay steel — titanium has no useful fatigue limit for a part cycling tens of millions of times.

High Performance Valve Spring and Titanium Retainer Set, 911 (993) · Patrick Motorsports

Billet aluminium, coil-on-plug provision

The BBi kit is the one that matters for this build because it carries the ignition: coil-on-plug in place of the twin distributors, which is the change that lets the engine run modern management at all. The billet sets from Patrick and Tarett are the answer if the distributors stay.

Air-Cooled EFI Valve Cover and Ignition Kit · BBi Autosport US$1,450 as of 2026-08-17

2 alternatives

• Billet Aluminium Valve Covers, 911 (993) · Patrick Motorsports
• Billet Aluminum Valve Cover Set, 911/964/993 · Tarett Engineering · US$431

Head stud kit and gasket sets

Air-cooled heads seal against the barrel without a conventional head gasket, so this position is studs and the rest of the top end. Swindon supply a stud kit for the 24-valve conversion; its material is not published, and this catalog will not assume titanium for the one fastener group carrying the head clamping load.

24V Cylinder Head Stud Kit · Swindon Powertrain £972 as of 2026-08-18

1 alternative

• 993 Engine Gasket Set - Cylinder Heads (GAS 993 100 902 00) · Victor Reinz · US$518

Adaptor to retain the factory pump

A dull part that says a lot. The 24-valve heads move things the factory pump mounting relied on, and somebody engineered an adaptor so the car keeps its power steering. The existence of this part is a better measure of how finished the conversion is than any power figure attached to it.

24V OEM Power Steering Adaptor · Swindon Powertrain £2,266 as of 2026-08-18

Two compact units, matched to displacement

Two small turbochargers on a 4.0 with four-valve heads is a different proposition from two small turbochargers on a two-valve 3.6 — the engine swallows far more air for the same boost. The catalogued upgrades all target the original 993 Turbo installation, which is the sensible starting point. Note that the GT2 K24 units are handed: left and right are different part numbers.

TTE800 Upgrade Turbochargers, 911 Turbo (993) · TTE Global (The Turbo Engineers)

6 alternatives

• TTE750 Upgrade Turbochargers, 911 Turbo (993) · TTE Global (The Turbo Engineers)
• BACK-ORDER BorgWarner K24 Turbo For Porsche 993 GT2 - LEFT (TUR 993 123 013 82 / 53249887003 / 993123113HP) · BorgWarner · US$3,548
• BACK-ORDER Borgwarner K24 Turbo For Porsche 993 GT2 - Right Side (TUR 993 123 014 82 / 53249887004 / 993123114HP) · BorgWarner · US$4,246
• Race Turbocharger K24/K26, Left, 911 Turbo / GT2 (993) · FVD Brombacher
• Race Turbocharger K24/K26, Right, 911 Turbo / GT2 (993) · FVD Brombacher
• K24 18GXT Compressor Wheel Upgrade, 911 Turbo (993 / 996) · Protomotive

Printed compressor or turbine housings are custom work. Nothing additively manufactured is catalogued for this application.

Six throttles under a plenum, drive-by-wire

There is normally a fork here, because individual throttle bodies and turbocharging pull in opposite directions: ITBs earn their keep on throttle response in a naturally aspirated engine, and a boosted engine wants a plenum it can pressurise. Swindon’s kit sidesteps it — six throttles built with Jenvey, bolting straight to the 24V heads, with a GT3-type plenum mounted on top and one electric motor per bank. Throttles under a plenum work boosted; bare trumpets do not. The remaining entries are the naturally aspirated answers.

24V Six Throttle Body Kit with Fly-by-Wire · Swindon Powertrain £6,120 as of 2026-08-18

4 alternatives

• Carbon GT3 Plenum and Filter Kit · Stuttgart Classica · £3,995
• EFI Throttle Bodies, 45–48 mm, 911 (964 / 993) · AT Power
• Air-Cooled EFI Individual Throttle Body System · BBi Autosport · US$13,500
• GT3 Intake Plenum Conversion Package With Motec M130 Drive-By-Wire Coil-On-Plug Ignition For 3 Bolt Heads 964 993 Engines · Patrick Motorsports · US$25,929

Air-to-air, full width

The 993 Turbo's charge coolers sit in the rear wings and are the quietest limit on the standard car. A full-width core is the catalogued upgrade.

Turbo Intercooler / Charge Air Cooler - 630 Ci Full Width Type (1978 - 1994) Porsche 911 Turbo / 930 / 965 (TUR FPOR 0315) · Patrick Motorsports US$4,459 as of 2026-08-17

Flow-matched injectors sized to target

The catalogued 42 lb set suits an uprated standard Turbo. A 4.0 at serious boost needs more, and the size is a function of a power target nobody here has measured, so no figure is given.

42 lb Flow-Matched Fuel Injectors, 911 Turbo (993) · Five O Motorsport

Standalone, drive-by-wire, CAN

One thing worth knowing before choosing: BBi's system and Rywire's harness are the same electrical architecture bought two ways. Rywire is BBi's technical partner and builds the harness inside the BBi package. Buying both is buying one thing twice.

Air-Cooled EFI Electronics and Wiring · BBi Autosport US$10,750 as of 2026-08-17

4 alternatives

• Mil-Spec EFI Engine Harness, 911 / 964 / 993 Twin Plug · Rywire Motorsport Electronics
• Patrick Motorsports EFI Chassis To ECU Wire Harness By MoTec (ELE M 6598 M130 C PMS) · Patrick Motorsports · US$4,196
• Engine Management and EFI, Dual Plug, 911 (964 / 993) · Clewett Engineering
• Mil-Spec Motorsport EFI Engine Harness, air-cooled 911 · Technica RaceWire

Cam and crank position, distributor removal

Small parts, but they are what physically ends the distributor era on this engine.

Air-Cooled EFI Cam Sensor Kit · BBi Autosport US$235 as of 2026-08-17

1 alternative

• Air-Cooled EFI Distributor Block-Off · BBi Autosport · US$85

High output alternator

Coil-on-plug ignition, electric fuel pumping and a full sensor set draw far more than the 1995 harness expected. The 240 A units exist because of exactly this.

High Output 240 A Alternator, 911 (964 / 993) · PMB Performance

1 alternative

• High Output 240 A Alternator, 911 (964 / 993) · Classic Retrofit

Inconel 625

Turbine inlet temperature is where titanium stops being the answer. Ti-6Al-4V loses strength well below the temperatures a boosted exhaust manifold sees continuously; a nickel superalloy does not. Inconel 625 is heavier than titanium and lighter than the steel it replaces, and it survives. K-Line's 993 Turbo manifolds carry the heat exchanger, which keeps cabin heat — the thing most race exhausts quietly delete.

Inconel 625 Manifolds with Heat Exchanger, 911 Turbo (993) · Kline Innovation

3 alternatives

• Inconel 625 Exhaust System, 911 Turbo (993) · Kline Innovation
• Inconel 625 100-Cell X-Pipe, 911 Turbo (993) · Kline Innovation
• Inconel 625 Silencer Section, 911 Turbo (993) · Kline Innovation

Titanium or ARP studs and nuts

Exhaust studs are consumables on an air-cooled 911 — they seize, then they snap in the head. This is a small amount of money against a large amount of grief.

Titanium Exhaust Manifold Studs and Nuts, Porsche · Silverlake Projects

1 alternative

• Exhaust Manifold Studs and Bolts, Porsche · ARP (Automotive Racing Products)

Composite, sealing to the tinware

The shroud is the largest single piece of engine tinware and it is not decoration: it directs every bit of cooling air the engine gets. It is also not interchangeable here — four-valve heads change the shape the shroud has to seal against, so the 24V build needs the shroud made for it and the generic composite shrouds below belong to a two-valve engine. Whichever is fitted has to seal as well as the steel did; fit matters more here than on any body panel.

24V Carbon Fan Shroud · Swindon Powertrain £2,119 as of 2026-08-18

3 alternatives

• Carbon Fan Shroud, air-cooled 911 · Stuttgart Classica · £995
• Fan Shroud with Integrated Heater Block-Off, 911 (964 / 993) · Stuttgart Classica
• NEW STOCK! Composite Engine Tin Surround For Porsche 911 with 964 / 993 Engine Conversions - Without Air Shroud (ENG 911 36 COMP ETS PMS) · Patrick Motorsports · US$1,395

Carbon or carbon/Kevlar

Same argument as the shroud, in more pieces. Carbon/Kevlar rather than plain carbon is the sensible choice for anything below the engine, where impact and abrasion resistance is worth more than the last few grams.

Composite Engine Tinware, 911 (964 / 993) · Stuttgart Classica £3,295 as of 2026-08-18

Single-belt RS conversion or serpentine

The factory RS ran a single belt where the standard car ran two. Two independent makers offer the conversion, which says something about how well it works. The RSR serpentine kit is the more thorough version of the same idea.

Billet Aluminium Fan Hub, 911 (964 / 993) · Rothsport Racing

3 alternatives

• RS Fan Hub Conversion, 911 (964 / 993) · Stuttgart Classica · £149
• 993 GT3 RSR Serpentine Pulley Conversion Kit (ENG 993 106 151 80 RSR PMS) · Patrick Motorsports · US$1,680
• Engine Cooling Fan Impeller - Porsche 964 / 993 (ENG 964 106 015 31) · Porsche AG · US$802

Auxiliary coolers with thermostat

The 911's oil is half its cooling system, and a boosted 4.0 asks a great deal more of it than a 3.6 did. The thermostat matters as much as the cooler: over-cooled oil on a cold morning is its own kind of damage.

Porsche 964 993 RSR Auxiliary Engine Oil Cooler System - No AC (OIL 964 207 RSR PMS) · Patrick Motorsports US$1,330 as of 2026-08-17

3 alternatives

• 1989 - 1998 Porsche 964 / 993 - Dual Front Engine Oil Cooler System (OIL 964 207 DFOC PMS) · Patrick Motorsports · US$670
• Heat Exchanger / Oil Cooler - 25 Row Proline STD 9 Series - SETRAB (OIL SET 50 925 7612) · Setrab · US$410
• Setrab 180F Engine Oil Thermostat Set AN-12 Universal (OIL 901 107 T180 AN12 PMS) · Setrab · US$231

Updated scavenge and return

A known weak point on the 993 Turbo, and the updated scavenge line exists because of it.

Turbocharger Oil Scavenge Line Update, 911 Turbo (993) · Turbo Kraft

1 alternative

• NEW STOCK! 993 Turbo Oil Return Pipe Set - Left & Right Sides (TUR 993 107 338 53 PMS) · Patrick Motorsports · US$300

Structural carrier, Turbo pattern

The clearest gap in the whole catalog, and it lands squarely on this build. The 993 Turbo's engine carrier is a structural part and nobody makes an alternative to it. Rennline's tubular carrier is explicitly non-Turbo — it is linked to a different factory reference and that exclusion is deliberate, not an oversight. Stuttgart Classica's 753 g grade 5 titanium support is the RSR pattern, not a proven substitute for the Turbo carrier, so this catalog does not claim it as one. For a twin-turbo 4.0 the honest answer today is the factory part.

Tubular Engine Carrier, 911 (964 / 993 non-Turbo) · Rennline US$649 as of 2026-08-17

1 alternative

• Titanium RSR Engine Support · Stuttgart Classica · £395

Factory reference: 993 115 021 53 Engine carrier

Both alternatives listed are near misses, not replacements. Verify interface before fitting either.

Semi-solid or solid

Semi-solid is the road answer and solid is the track answer, and the gap between them is measured in how much of the engine you want to feel through the seat. Tunable mounts exist precisely because that line is personal.

Semi-Solid Engine and Transmission Mounts, 911 (993) · WEVO

5 alternatives

• Tunable Semi-Solid Engine Mounts, 911 (964 / 993) · Rennline
• Semi-Solid Engine Mount Upgrade V2, 911 · Function-First
• Euro RS Engine Mount Set, 911 (964 / 993) · Patrick Motorsports
• Solid Engine Mounts, 911 (964 / 993 / 996 / 997) · Rennline
• Solid / Sport / RSR Transmission Mount For Porsche 964 / 993 Turbo (TRA 993 375 055 70 PMS) · Patrick Motorsports · US$235

Factory reference: 993 375 049 05 Engine mounting

Lightweight or midweight, Turbo torque capacity

Midweight rather than lightest-possible is the considered choice on a torque-rich turbo engine — a very light flywheel makes a boosted engine harder to drive smoothly, not easier. The catalogued Turbo package is made by Aasco.

Midweight Flywheel and Sport Clutch Kit, 911 Turbo (964 / 993 / 996T / 997T) · Aasco Motorsports US$3,879 as of 2026-08-17

2 alternatives

• Euro RS Lightweight Clubsport Single-Mass Flywheel and Clutch Conversion, 911 (964 / 993) · Patrick Motorsports
• RS-Type Clutch Conversion Kit, 911 Turbo (964 / 993 / 993TT) · Lufteknic

Torque biasing or clutch type

A 4.0 biturbo will find the limit of the standard differential quickly. On the Turbo's four-wheel drive the front axle behaviour is part of the same decision.

Torque-Biasing Limited Slip Differential, G50 Six-Speed (993) · Wavetrac (Autotech Driveline)

1 alternative

• CLUB Limited Slip Differential, GT2 / GT3 / GT3 RS / 964 (996 / 997) · Guard Transmission

Crankshaft, camshafts, drive gears, valve springs, head studs, rod bolts

Every one of these is either fatigue-loaded for the life of the engine or carries a clamping load that depends on the material's stiffness. Titanium's lower modulus is a virtue in a connecting rod and a liability in a head stud. Substituting here is the most common way an otherwise well-specified engine fails.

Peripheral brackets, covers, exhaust hardware

Titanium hardware belongs where the fastener locates a part rather than clamping a structural joint. Case through-bolts sit on the wrong side of that line, which is why the catalogued range is held at low confidence until each kit has been read individually.

Titanium Engine Fastener Range · Stuttgart Classica

Catalogue-level entry, not yet verified kit by kit.