The Original 911

01 Layout

Everything has a place

Porsche showed the car as the 901 at the Frankfurt motor show on 12 September 1963 and started series production at Zuffenhausen on 14 September 1964. At the Paris Salon that October, Peugeot objected: it claimed the French rights to three-digit model names with a zero in the middle. Porsche had built 82 cars as 901s before the badge became 911, and the engine and parts numbers kept the 901 prefix.

The brief was a successor to the 356: a 2+2 fastback with a rear-mounted six and more room inside. Ferry Porsche had the wheelbase cut from 2.40 m to 2.20 m to keep the fastback. Ferdinand Alexander "Butzi" Porsche designed the body, Hans Mezger and Ferdinand Piëch developed the engine, and Helmuth Bott ran the road testing that shaped the chassis.

Take the body shell away and the layout is easy to read. The fuel tank and the spare wheel sit in the nose. The cabin floor carries a central tunnel. The gearbox sits ahead of the rear axle, and the engine hangs behind it, outside the wheelbase. Pick a system in Fig. 02 to see where its parts live, then start the engine to watch fuel, oil and heat move.

The numbers that shape it

The short-wheelbase car is compact. It is 4,163 mm long, 1,610 mm wide and 1,320 mm high, on a 2,211 mm wheelbase, with tracks of 1,337 mm at the front and 1,317 mm at the rear. It weighs about 1,080 kg (some sources say 1,030 kg) and has about 150 mm of ground clearance. The body is a welded steel monocoque with bolt-on front wings.

Hanging the engine behind the axle puts roughly 40 percent of the weight on the front wheels and 60 percent on the rear. That gives the car its traction, and its reputation. Helmuth Bott, who ran the testing, found that the first series cars reacted "too viciously to steering corrections and oversteer". Porsche's own account says it bolted an 11 kg cast-iron weight into each corner of the front bumper for customers who complained, listed in the parts book as a bumper reinforcement. The lasting fix was a smoother bearing under each front strut, after which the weights went. If your car still has them, they are part of its history: keep them.

The 1969 B-series moved the rear wheels 57 mm back, to a 2,268 mm wheelbase, without making the body longer. This guide covers the short-wheelbase cars built from 1964 to 1967. Parts and specifications changed even within those years, so check every figure against the type numbers stamped on your engine and gearbox.

Heat for the cabin

There is no water and no radiator. The engine fan blows air over the cylinders, and some of it passes through the heat exchangers, steel jackets around the exhaust headers. That warm air is then sent into the cabin or dumped. A petrol-burning Webasto heater was an option. The heat exchangers carry exhaust, so treat any exhaust smell from the vents as a fault to fix before you drive.

Electrics

The car runs on 12 volts from one large battery in the nose. The alternator lives inside the fan housing, and the fan is pressed onto its shaft. Porsche's parts book calls it a generator, a word it also uses for the 912's dynamo. The voltage regulator is a separate unit, as on every 911 up to 1981.

02 Engine

The air-cooled flat-six

The Type 901 engine is an air-cooled flat-six of 1,991 cm³, with an 80 mm bore and a 66 mm stroke. It has two valves per cylinder, one chain-driven overhead camshaft per bank, and dry-sump lubrication. On a 9.0:1 compression ratio it makes 130 PS (DIN) at 6,100 rpm and about 174 Nm at 4,200 rpm, and it is good for 6,500 rpm.

It is built in pieces. The aluminium-alloy crankcase splits vertically down the centre of the crank and is held together by through-bolts. Magnesium cases came later, in 1968 or 1969, depending on the source. The forged crankshaft runs in eight main bearings, the eighth a nose bearing at the pulley end, and each of the six connecting rods has a crankpin of its own. Each cylinder is a separate finned barrel with its own aluminium head. One cam housing per bank spans the three heads and carries the camshaft and rockers.

Below the crank, a gear-driven intermediate shaft does the timing work. Two chains run from it, one to each camshaft, at the pulley end of the engine, and the cams turn at half crank speed. The same shaft drives the pressure and scavenge oil pumps inside the crankcase.

Which cylinder is which

• The left bank holds cylinders 1, 2 and 3, and the right bank holds 4, 5 and 6. Left and right are as you sit in the car.
• Both banks are numbered from the fan end. No. 1 is the left cylinder nearest the fan and No. 3 the left one nearest the gearbox. No. 4 and No. 6 sit at the same ends on the right.
• The firing order is 1-6-2-4-3-5, one cylinder every 120° of crank rotation.
• The Z1 notch on the crank pulley marks top dead centre for No. 1 and No. 4. It lines up with the crankcase joint, or with the notch in the fan housing. Turn the engine only clockwise at the pulley. Turning it backwards can damage the chain tensioners.

Chains and tensioners

Each chain has a tensioner that presses an idler arm against it. The original tensioners are sealed, spring-loaded units, damped by their own oil like a small shock absorber. These tensioners fail with age, and nothing warns you first. When one goes, the chain goes slack and can jump a tooth, and the valves hit the pistons.

The usual cure is the oil-fed tensioner Porsche introduced on the 1984 Carrera. Pelican's bolt-on kit is for 1969–83 engines. On 1965 and 1966 engines it will not fit, because the cam-tower oil lines attach differently, so those engines need the later chain housings and covers, fitted during a rebuild; Pelican says 1967 engines can be converted the same way. Fit the later idler arms (930.105.509.00 and 510.00), which do not bind, and replace any of the six chain ramps that are pitted.

Cam timing

Each cam sprocket bolts to its hub through a ring of holes, 17 in the sprocket and 16 in the hub. Only one pair lines up at a time, so moving the locating pin one hole moves the cam by about 1.3°, or 2.6° at the crank, like a vernier. To check the timing, set the valve clearance to 0.10 mm and put a dial gauge on the No. 1 intake valve's spring retainer. The gauge reads that valve's lift at overlap top dead centre.

For the cams used on most 1965 engines (type 901/01), the factory figure is 4.2–4.6 mm of lift, with 4.3 mm ideal. That number reaches us only through a forum post quoting the factory manual, and the figure for the 901/05 was not found. Confirm both in the manual before you set a cam. The full procedure is in chapter 08.

Valve clearance

Set intake and exhaust valves to 0.10 mm with the engine stone cold, after at least four hours. Start with No. 1 at top dead centre on its firing stroke: Z1 at the crankcase joint, and the distributor rotor at the notch in the distributor body. Then turn the crank 120° at a time and do the cylinders in firing order, 1, 6, 2, 4, 3 and 5. Use a feeler blade on a handle. Pelican's writers say "a normal feeler gauge will not do the job well".

Inside one cylinder

Fig. 04 cuts one cylinder open. The intake valves are on top of the engine and the exhausts underneath. Each carburettor sits above its bank's intake ports, and the exhaust leaves from below into a heat exchanger. The exhaust valves are hollow and sodium-filled to carry heat away, and every valve has an inner and an outer spring.

Each piston carries three rings, and Mahle made the cylinder and piston sets. A head gasket seals each head to its cylinder. Under each cylinder sits a base gasket, 0.25 or 0.50 mm thick, which sets how high the cylinder stands.

03 Oil & air

Dry sump, big fan

A dry-sump engine keeps its oil somewhere else: in a separate tank in the right rear wing, behind the wheel. A pressure pump draws oil from the tank and feeds the bearings and the cam housings. A second pump, the scavenge pump, empties the crankcase as fast as oil drains into it, and sends it back to the tank through a spin-on filter. Both pumps sit inside the crankcase, driven by the intermediate shaft. With no pool of oil under the crank, the engine can sit low, and hard cornering cannot starve the pump of oil.

A thermostat in the crankcase keeps oil out of the cooler until it is warm. The cooler bolts to the right side of the engine under the fan housing, in the stream of cooling air. These cars have no front-mounted cooler; that arrived with the 1969 911S. A strainer screen sits in the bottom of the crankcase under an eight-nut sump plate.

The same fan cools everything. It has 11 blades and stands upright in the fan housing on the alternator's shaft, turned by a V-belt from the crank pulley. The belt tension is set with shims between the two halves of the fan pulley.

Checking the oil

The dipstick is in the tank's filler neck. Check it with the engine hot and idling, on level ground. A reading taken cold, or with the engine off, comes out low, because oil sitting in the crankcase has not yet been pumped back to the tank. If you top up to that reading, you overfill it.

Changing it

1. Warm the engine, then switch it off and raise the car level.
2. Drain both the tank and the crankcase. On a dry sump, draining only one leaves much of the old oil behind.
3. Take off the sump plate and clean the strainer screen. The plate is held by eight nuts. Use new gaskets.
4. Fit a new spin-on filter on the tank.
5. Refill through the tank. About 8 US quarts (7.6 litres) goes in at an oil change on a car built before 1973 (Pelican's figure).run the engine until it is hot, then read the dipstick at idle.

Sources disagree on the drain-plug torque, so take it from the factory manual. The cooler is reached by taking off the right-hand heat exchanger, and the thermostat sits beside the breather cover. Both are places to look when you trace a leak.

04 Fuel & spark

Carburettors and points

Fuel lives in a 62-litre tank in the nose (one 1963 specification says 68 litres). An electric Bendix pump sends it to two triple-choke carburettors, one above each bank, so each cylinder has its own barrel.

Solex or Weber

The first engines, type 901/01, ran two Solex 40 PI carburettors. They have no float. An overflow holds the fuel level steady in each chamber, and an extra engine-driven pump returns the surplus to the tank. They were hard to keep in tune and had a flat spot in the middle of the rev range.

From early 1966 the 901/05 engine, starting at engine number 907001, used two Weber 40 IDA 3C carburettors with ordinary floats. Sources date the changeover anywhere from February to the middle of 1966, and many earlier cars were converted in period. If yours still has its Solex units, keep them: they are now sought after.

Setting up the Webers

Never look down into the carburettor stacks with the engine running: it can spit fuel and flame back through them.

1. Get the engine fully warm, and set the idle to 1,000–1,100 rpm.
2. Balance the airflow through all six throats with a flow meter such as a Unisyn. Use each carburettor's idle-speed and air-correction screws to bring every throat up to the highest one.
3. Set each idle mixture screw. Turn it in until the idle starts to drop, then back it out about an eighth of a turn.
4. Check the linkage. Both banks must open together. If one starts to open first, Pelican's fix is to shorten its drop link.blip the throttle: both linkages move at the same instant.

Early Webers have no adjustable accelerator pump, and their small idle jets can make them spit back. When you rebuild one, set the float tab to 18 mm. Solex setup figures were not found for this guide, so use the factory manual for those.

Points, cap and plugs

Ignition comes from a single set of contact-breaker points, used from 1965 to 1976. The distributor is at the back of the engine, next to the left chain housing (Pelican has you take it out to reach the left cam's oil line). It turns at half crank speed, so its rotor sweeps all six cap towers every two turns of the crank. Both Bosch and Marelli distributors are listed for 1965–69 cars. Marelli caps can no longer be bought, but a Bosch distributor drops in.

• Points gap: 0.016 in (0.41 mm) as the starting point on 1965–68 cars, then set the dwell.
• Dwell and timing: the factory figures for the 901/01 and the 901/05 could not be confirmed for this guide. Take them from the factory manual for your engine's type number. Fig. 06 shows the mechanism, not the numbers.
• Static timing: with Z1 at the crankcase joint, the rotor should point at the notch in the distributor body. If the engine will not fire, the crank was probably at No. 4's top dead centre. Turn it one more full turn, then lift the distributor out and refit it with the rotor at the notch. A distributor that is half a turn out can backfire through the carburettors.
• Plugs: M14, tightened to 25–30 Nm with no anti-seize. A modern cross-reference for the 2.0 is the Bosch W3DP.

05 Gearbox

Clutch, five speeds, one differential

The gearbox and the differential share one aluminium case, the transaxle, which bolts to the front of the engine and sits ahead of the rear axle. Power goes in at the back, through the clutch to the input shaft. The input shaft runs forward over the differential to the gear stack in the nose. Each speed is a pair of gears, one on the input shaft and one on the pinion shaft below it. The pinion shaft carries the power back to the differential's ring gear, which turns the output flanges and the half-shafts. Both shafts and all their gears hang on an intermediate plate, which is closed at the front by an end cover.

Porsche called the family the 901 gearbox. A car from these years normally has a type 901/0 five-speed (built to mid-1965) or a 902/1 (1965–67). A four-speed 902/0 was offered, and a ZF limited-slip differential was optional. The Sportomatic semi-automatic arrived for 1968. The case is aluminium, sand-cast on the earliest boxes; magnesium cases arrived in 1969.

The lever works a dogleg gate. Reverse is up and to the left, and first is down and to the left in the same plane; second and third share the middle plane, and fourth and fifth the right. Every forward gear has Porsche's split-ring synchromesh. When the sliding sleeve touches the split ring, drag turns the ring against a stop, which tightens brake bands inside it so the ring grips harder still. Once the gear is turning at shaft speed, the sleeve slides onto its dog teeth. First gear has one brake band and the others have two.

Fig. 07 uses the 902/1 ratios. Its road speeds assume a 165 HR 15 tyre that rolls about 1.98 m per turn, which gives about 203 km/h at 6,500 rpm in fifth, close to the quoted 210 km/h top speed. It shows no reverse ratio because no source confirmed one.

The clutch

The clutch is a single dry plate by Fichtel & Sachs, 215 mm across on 1965–69 cars. It is push-type: the release bearing sits on the gearbox and pushes on the pressure plate. The cable runs straight to the release arm, and the adjuster is under the gearbox. Set about 25 mm of free play at the pedal. With the pedal pushed all the way down, the release arm should travel about 15 mm. Early 1965 cars used a different pressure plate from later ones, so match the part to your car.

Replacing the clutch means separating the engine from the gearbox. While they are apart:

• renew the release fork's bushing and guide clips;
• tap a new pilot bearing squarely into the flywheel;
• fit a new rear main seal;
• always fit a new or resurfaced flywheel.

The six flywheel bolts are renewed every time and tightened in criss-cross steps of about 20 Nm, up to 150 Nm. The pressure-plate bolts take 20 Nm. The flywheel bolt heads are shallow, so keep the tool square on them or they strip.

Shift linkage and half-shafts

The lever sits in a ball cup on the tunnel floor and moves a single rod back through the tunnel to a coupler under the car, which joins the gearbox's selector rod. Before you take the coupler apart, mark its position and rotation. If it goes back a few degrees out, the gate feels wrong. Grease the ball cup. On cars before 1974, the reverse lockout springs wear.

The 1965 half-shafts use Nadella universal joints, not constant-velocity joints; Löbro CV-jointed shafts arrived around 1967. The flange bolts take 47 Nm on Nadella shafts (M10) and 43 Nm on early Löbro shafts (M8). The flanges are located by roll pins, so pry them gently. Lock the shafts with first gear and the handbrake while you work.

What you can do at home

A worn first-gear synchro is a realistic home job of about five hours:

1. Take off the end cover. Reverse parts may drop out.
2. Hold the intermediate plate to the case with a nut and spacer on one stud.
3. Remove the first/reverse fork and slider.
4. Undo the hub bolt with an impact wrench.
5. Take out the snap ring, synchro ring, blocks and band, then pull the hub.
6. Refit with a new gasket and selector seal.

Setting up the ring and pinion or rebuilding the differential needs gauges and shims that most garages don't have. Leave that to a specialist.

06 Chassis

Torsion bars, struts and discs

Torsion bars do the springing at both ends of the car. At the front, MacPherson struts carry the hubs on single transverse lower arms. A longitudinal torsion bar runs inside each arm's pivot tube: 18 mm thick on 1965–68 cars, though one Pelican page says 19 mm. Its back end sits in a lever with an adjusting screw, and that screw sets the front ride height.

At the rear, semi-trailing arms carry the hubs. Two transverse torsion bars, one for each side and 23 mm thick, run inside a tube across the car. Each spring plate sits on its bar's outer splines and bolts to the trailing arm, and eccentric bolts at that joint set the camber and toe.

Steering is by a ZF rack and pinion, 2.25 turns from lock to lock. The brakes are solid discs all round, 282 mm at the front and 285 mm at the rear, with fixed two-piston calipers. The very first cars had Dunlop-licensed calipers like the 356's, and ATE calipers followed. The 1965 car has a single hydraulic circuit and a 19 mm master cylinder mounted under the car; dual circuits arrived for 1968. The handbrake works small drums inside the hats of the rear discs. The wheels are 4½J × 15 steel rims with chrome hubcaps, on 165 HR 15 radials.

Taking out a rear bar

1. Put the car level on four stands under the inner torsion tube. Don't use the bar covers you are about to remove, and don't stand the car on the engine or gearbox: Pelican warns that can make it unstable.
2. Jack under the trailing arm and raise it slightly, so the jack carries the arm.
3. Take out the damper's lower bolt.
4. Remove the cover. It has four bolts, one of them hard to see.
5. Lower the jack slowly until the plate is slack and the bar is no longer twisted.
6. Trace the plate's outline on the body. It is your ride-height reference when the car goes back together.
7. Remove the four fasteners that join the plate to the arm: the toe eccentric, the camber eccentric and two 19 mm bolts. Keep the arm on the jack.
8. Free the plate and draw out the bar.each bar carries an L or R mark. Grease the splines when it goes back.

Ride height and the splines

The two ends of the rear bar have different numbers of splines: 40 at the inner end (9° per tooth) and 44 at the outer end (8°10′ per tooth). Turn the bar one tooth one way and the plate one tooth back the other way, and the net change is 50 minutes of arc, about 7 mm of ride height. One degree is roughly 8–9 mm. Fitting the plate higher than your chalk line lowers the car. Replace bars in pairs, and keep the bolts snug until the car is back on its wheels. Expect it to take more than one try.

Pelican's ride-height figures compare the height of the wheel centre with the height of the torsion-bar centre, and the two ends run opposite ways:

• Front: the wheel centre sits 108 mm above the torsion-bar centre on European cars (99 mm on US cars), within 5 mm from side to side.
• Rear: the torsion-bar centre sits 12 mm above the wheel centre on earlier cars, within 8 mm from side to side.

Pelican measures with the spare wheel fitted and the trunk otherwise empty, and says to check the factory booklet for your year. Then set the alignment in order: ride height first, then camber, then toe. The 1965–67 factory alignment figures could not be confirmed for this guide. Pelican's general 911 guidance is about 6.5° of caster and +10′ of front camber with a little toe-in. At the rear it is about −1° of camber with zero toe.

Brakes

• Calipers: don't split the halves unless they leak. Push the pistons out with low-pressure air, and lubricate the new seals with brake fluid. Set each piston's recess at 20° to the pad slot, which stops squeal.
• Bleeding: right rear, left rear, right front, left front, more than once each. Use DOT 3 or DOT 4 fluid, never DOT 5.
• Handbrake: through the hole in the disc, turn the star-wheel adjuster until the shoes lock, then back it off four or five teeth. The handbrake should hold within about four clicks; if it doesn't, adjust the cables.

Lifting the car

Chock the wheels that stay on the ground, and set the handbrake and first gear. At the rear, jack under the sump plate on a block of wood, or at the side jacking points, and put the stands under the torsion-tube covers. At the front, jack at the lower-arm mounting points and put the stands under the front torsion-bar mounts. Never jack on the floor pan or the rear seam. Shake the car before you get under it, and add backup stands.

07 Teardown

Taking it apart in a home garage

An original 1965 911 is now a six-figure car. Hagerty valued a 1965 coupé at $185,000 in October 2024 (its condition tier isn't shown), and most auction results from 2024 to 2026 fell between about $130,000 and $285,000. Buyers check a car against Porsche's factory record card, the Kardex, and the Certificate of Authenticity, so original parts and matching numbers carry real money. Take it apart the way an archaeologist digs: slowly, recording everything.

Before you pick up a spanner

• Record the numbers. The chassis number is stamped into the body under the front-trunk carpet, with an aluminium plate beside it; the engine number is on the right side of the crankcase, on the fan-housing support beside the fan. Photograph both. Porsche’s Production Specification, which replaced the Certificate of Authenticity in 2019, no longer lists engine and gearbox numbers; a Porsche Classic Technical Certificate checks the fitted numbers against the factory record.
• Photograph every stage from several angles before a part comes off, and again with it off. Hoses, wire routing and tinware are much easier to refit from photos than from memory.
• Bag and tag. One labelled bag or tray per group, as in Fig. 09. Parts that wear together go back together: each head, rocker and piston returns to the cylinder it came from, and each bearing shell to its journal.
• Keep everything, worn and broken parts included. Many owners swapped the original Solex carburettors for Webers in period; the Solex units are now sought after.
• Keep a log of every measurement, shim and spline position as you go. You will need it at reassembly, and the next owner will want it.
• Be realistic about time. Excellence puts a worst-case restoration of an early car at 2,500–3,000 hours.

Space, tools and safety

You need room to walk all round the car with the engine out beside it, a bench, good light, a floor jack and four axle stands. Get an engine stand of the Porsche type, which supports the case by its lip; a generic stand can damage it. Most of the work needs ordinary metric tools. These are the special ones:

• a cam holder (Porsche P202) and a 46 mm crowfoot for the cam sprocket nuts, plus a locating pin (P212; an old spark-plug tip works);
• a flywheel lock and a flywheel-bolt tool;
• an extra-long Allen key, or an Allen socket on an extension, for the head nuts (Pelican's teardown mentions both 8 mm and 10 mm, so check yours first);
• a long 8 mm Allen with a socket end, and an angled 13 mm spanner, for the heat-exchanger nuts;
• a collet-type stud remover, snap-ring pliers, a hardwood dowel for the wrist pins and a soft mallet;
• a metric dial gauge on a stand, and a feeler blade on a handle for the valves.

Getting the engine out

Pelican says Porsche recommends dropping the engine and gearbox together and separating them on the floor; many owners drop the engine alone. Pelican wrote up the order below on a later car and says it is "almost the same" on all of them. Confirm each step on your car before you undo anything.

1. Disconnect the battery, negative first.
2. Drain the crankcase and the oil tank.
3. Raise the rear of the car, higher than you expect. The engine has to come down and out under the bumper.
4. Disconnect the oil lines. Hold the hard line with two spanners, then take off the rubber hose to the tank.
5. Unhook the clutch cable. On early cars it attaches directly to the release arm.
6. Label and disconnect the starter wires, the reversing-light switch and the speedometer drive.
7. Disconnect the heater hoses at the heat exchangers.
8. Undo the shift coupler through the trap door in the tunnel. Mark its position first.
9. Disconnect the fuel lines, the wiring harness, the earth strap, the breathers and the accelerator rod.
10. Decide how it comes out. To drop the engine and gearbox together, undo the half-shafts at the gearbox flanges and support the gearbox mount. Early cars use a one-piece mount bar. To drop the engine alone, undo the four nuts that join the engine to the gearbox, and support the gearbox so its mounts aren't strained.
11. Put the jack under the sump plate and raise it until it just begins to take the weight. Then remove the engine mount bolts.
12. Lower the engine about 30 cm, until the fan clears the bumper, then draw it back. Change the jack's angle until the engine comes off the gearbox studs. It becomes unstable at that moment, so have your helper steady it.nothing still joins the engine to the car: no wires, cables, hoses or earth strap.

Taking it apart

Fig. 09 follows this order. Every group goes into its own labelled bag or tray, photographed before and after it comes off.

1. Air cleaners, carburettors, manifolds and distributor. Plug the intake ports.
2. Fan, fan housing, tinware and alternator. Mark the alternator's wires before you unplug them.
3. Clutch and flywheel. Lock the flywheel, and keep the bolt tool square on the shallow bolt heads.
4. Exhaust and heat exchangers. Soak the nuts in penetrating oil for days, then heat them, so the studs don't snap.
5. Chain-housing covers and oil lines, then the tensioners.
6. Valve covers, cam sprocket nuts, rockers and camshafts. The sprocket nut needs the 46 mm crowfoot and the cam holder, and Pelican warns it "may take two strong people". Keep the rockers and their shafts in order.
7. Chain housings. The chains stay in the engine until the case is split.
8. Heads and cam housings together. Loosen the head nuts evenly, a little at a time, and label each head by cylinder.
9. Cylinders. Keep each one with its own piston.
10. Pistons and wrist pins. Cover the openings in the case before you take out the circlips.
11. Oil cooler, breather and thermostat, the sump plate and intermediate-shaft cover, then the case fasteners. Two fasteners hide deep in the chain area. Split the case with a rubber mallet; never prise the halves apart.
12. Crankshaft and rods, chains, intermediate shaft and oil pump. Bend back the pump's lock tabs first, and keep every bearing shell in order. Renew both pressure-relief valve springs.

The head studs are set in with thread-locking compound. To remove one, heat the case and use a collet-type stud remover. Clean the parts in an aluminium-safe hot tank, and never sandblast the case: grit left in the oilways destroys bearings.

08 Rebuild

Putting it back together

An aluminium 2.0 case is a good base for a rebuild. Unlike the magnesium 2.2, 2.4 and 2.7 cases, it does not need inserts in its head-stud holes. Plan on about 76 hours of your own time before any machine-shop work: about 10 to remove the engine, 16 to strip it and 50 to rebuild it.

Inspection and the machine shop

• Crankshaft: have it crack-tested (Magnaflux). A used crank at its standard size is better than a reground one.
• Rods: fit new small-end bushes, and have the big ends resized.
• Cylinders: if your engine has later replacement cylinders, Mahle Nikasil ones can be honed and KS Alusil ones cannot be treated the same way. Ask the shop which you have.
• Valve guides: a wobble test first, then a bore gauge.
• Measurements: take bearing clearances, crank end float, guide wear limits and deck height for the 66 mm-stroke 2.0 from the factory manual. The figures in later manuals are for other engines, so don't borrow them.

Putting it back together

Reassembly reverses the teardown. These are the steps where most rebuilds go wrong.

1. Close the case. Coat the mating faces with a thin film of anaerobic sealant (Pelican uses Loctite 571 in one article and 574 in another). Fit new, lubricated O-rings on the through-bolts. Pelican uses Dow Corning 111; builders on the forums prefer green Viton O-rings and no silicone sealant. Hold each bolt with a ring spanner as you tighten its nut, so it can't turn and cut its O-ring. Tighten the through-bolts first, in stages and criss-cross, turning the crank after each one. Then tighten the 13 mm nuts round the edge, all before the sealant cures.the crank still turns smoothly by hand.
2. Fit the pistons and cylinders. Stagger the ring gaps around each piston, compress the rings, slide each cylinder on, then fit the wrist pin and new circlips. Use new base gaskets and keep the large cylinder fins downward. Hold each cylinder down with two head nuts until its head goes on.
3. Fit the heads and cam housings. Pelican sets all the head studs at the same height, 133–134 mm (one reader recommends 135 mm), so check the figure for your engine. Bolt each bank's three heads to its cam housing before they go on the engine, so they line up. Use the large washers under the head nuts, and turn the cam as you tighten. If it binds, back off and change the sequence.each camshaft turns freely in its housing.
4. Time the cams, as described below.
5. Fit the tensioners. If you fit the later oil-fed type, prime each one by pumping it under oil until no air comes out, and pull its retaining pin only once it is installed.
6. Set the valve clearances to 0.10 mm cold, in firing order (chapter 02).
7. Refit the oil system, tinware, fan, induction and ignition, then the clutch and flywheel.

Timing the cams

Pelican's procedure, written on a later engine, is the standard method. Do the left bank (cylinders 1–3) at No. 1, then repeat at No. 4 for the right bank.

1. Fit only the No. 1 and No. 4 intake rockers, so no other valve can touch a piston, and set both to 0.10 mm.
2. Mount the dial gauge on a cam-housing stud. It should bear on the edge of the No. 1 intake spring retainer, parallel to the valve, with at least 10 mm of preload.
3. Set the crank at Z1 on the crankcase joint. Turn each camshaft so the punch mark on its end faces up, and hold it with the P202 holder.
4. Fit the locating pin through the one sprocket hole that lines up with the hub. Keep the chain taut while you work, with locking pliers on the tensioner arm or with a mechanical tensioner.
5. Zero the gauge, turn the crank 360° to overlap top dead centre, and read the intake lift. To change it, move the pin to the hole that gives the reading you want, then snug the nut.the reading is the same after two more full turns (720°).
6. Repeat at No. 4 for the right bank, then tighten both sprocket nuts.

For the cams fitted to most 1965 engines (901/01), the target is 4.2–4.6 mm of lift, with 4.3 mm ideal. That figure is the factory manual's, reported in a single forum post; later 901/01 and all 901/05 figures were not found. A high reading means the cam is advanced. Builders aim to get both banks within a few hundredths of a millimetre of each other. They read the gauge with the nut tight, because friction, not the pin, holds the timing.

First start and break-in

1. Build oil pressure first. With no fuel and no spark, crank the engine about five times for 6–7 seconds each, until the gauge shows pressure.
2. Start it and let it idle for about 20 minutes, watching for leaks, then change the oil.
3. Drive gently: no more than 3,500 rpm for the first 500 miles, then no more than 4,500 rpm for a while.

Break-in advice varies. Another Pelican article says 4,000 rpm, non-detergent oil and 20 minutes at 2,000 rpm, so follow your engine builder or the oil maker. Opinions also differ on re-torquing the head nuts after the first few hundred miles; ask your machinist.

Gearbox and chassis

Join the gearbox to the engine before the pair goes into the car, or offer the engine up to a gearbox still in place. Lift it in by reversing the removal order, and reconnect the shift coupler exactly where you marked it. Then set the clutch free play and bleed the brakes. Set the ride height and alignment in that order (chapter 06), and only then road-test the car.

09 Reference

Numbers, tools and sources

Specifications

Torque values

These come from manuals and forum posts covering a range of years, and few are confirmed for the 1965–67 engine. Use them to sanity-check your work, and take the final figure from the factory manual for your engine's type number.

Engine numbers

Porsche Classic's parts catalogue gives the first engine number of each run:

Books and manuals

• Porsche 911 Workshop Manual (factory), 911 F, 1965–1971, two volumes in English, reissued by Porsche Classic. The specifications for your engine's type number come from here.
• Wayne R. Dempsey, How to Rebuild and Modify Porsche 911 Engines 1965–1989. Motorbooks, 2003. ISBN 978-0-7603-1087-8. A photo-by-photo engine teardown and rebuild.
• Bruce Anderson, Porsche 911 Performance Handbook. Motorbooks; first edition 1987, third edition (1963–1998) 2009, ISBN 978-0-7603-3180-4.
• Wayne R. Dempsey, 101 Projects for Your Porsche 911, 1964–1989. Motorbooks, 2001. ISBN 978-0-7603-0853-0.
• Peter Morgan, Original Porsche 911. Bay View Books, 1995; later editions to 1998. The reference for what is correct on an original car.
• Paul Frère, Porsche 911 Story. First published 1976; ninth edition with Tony Dron, Haynes, 2013, ISBN 978-1-84425-990-8.

Clubs

The Early 911S Registry and the Porsche Club GB Early 911 Register both cover cars built from 1964 to 1973, and their members have done most of these jobs before you.

Sources

Every fact in this guide comes from these sources, and an independent check compared the text against them. Many figures rest on a single source. Where a figure comes from a forum post, or the sources disagree, the text says so. Confirm anything you will set a tool to against the factory manual for your engine's type number.

Porsche

• Porsche Classic, parts catalogue 911 (1965–69), 1 Kat 073 (PDF)
• Porsche Newsroom, 60 Years of the 911: the first generation
• Porsche Newsroom, the 911's origins from the 754 to the 901 (German)
• Porsche Classic News 2016 (PDF): early handling and the bumper weights
• Porsche vehicle documentation FAQ

Specifications and history

• Excellence, 1965 Porsche 911 specifications
• Excellence 264, "The earlier early 911"
• Excellence 211, Helmuth Bott
• Wikipedia, Porsche 911 (classic)
• Philip Raby, the 2.0-litre 911, 1964–1967
• Porsche Club GB, early 911 buyer's guide
• Stuttcars, the 911 F-series story
• CAR, March 1965: first drive of the first 911
• Magneto, what's so special about the Mezger flat-six
• Sports Car Market, 1966 Porsche 911 profile
• Hagerty valuation tool, 1965 Porsche 911
• Kardex versus Certificate of Authenticity

Workshop procedures

• Pelican Parts, 101 Projects: jacking up, oil change, engine drop, clutch replacement, engine teardown, machine shop, engine rebuild, cam timing, chain tensioners, valve adjustment, ignition tune-up, timing, carburettor rebuild, carburettors, shifting, 901 first gear, half-shaft joints, heat exchangers, bleeding brakes, ride height, alignment, torsion bars
• Pelican Parts articles: engine rebuild, engine drop, valve adjustment, chain tensioners, torsion bars, caliper rebuild, oil coolers, oil leaks, static timing
• Porsche Club of America, cam timing
• Rennlist forum, the 901/01 cam timing figure
• Performance Developments, valve adjustment
• FCP Euro, valve adjustment on a classic 911
• derFix, the evolution of Porsche oiling systems, part 2 (PDF)

Gearbox

• Bluesky Motorsports, the 901 series transmission (PDF)
• Cogs Cogs, gear ratio charts
• California Motorsports, 901 transaxle specification
• Automotive Tech Info, an inside look at Porsche transmissions