The Lightweight Racing Interceptor (race uprated)
A unique roadcar; the Lightweight Racing Jensen Interceptor is the only lightweight version ever built. The original owner required an Interceptor manual which was as light as possible. To this end Jensen built the 1968 manual Interceptor with: no soundproofing, no power steering, no air conditioning, including a custom glass fibre louvred bonnet and a special manual radiator and considerable weight reduction, with no padding (that fills the normal cars), with lightweight aluminium road wheels. Only 23 right hand drive manual Interceptors were built. This car is the only original one-of-one unique, Lightweight Racing Interceptor. The car had race uprated suspension and a 440 Magnum Chrysler engine, rated at 375 hp (SAE), to make it more powerful for the original owner, to go racing in. The present owner bought the car in 1981 and has owned it ever since. At present the car has gone through an extensive restoration and been race uprated to make it the most powerful original engined, make and model, 60’s roadcar. The 440 cubic inch Chrysler has been stroked to 493 cubic inches (8.06 litres) and race uprated to over 1100 hp (net), producing 1100 hp (net) and 1100 lb ft of torque; with introduction of a nitrous oxide system; like Eleanor, the 1967 Shelly GT500 in the film Gone in 60 Seconds, but instead of the Mustang’s 427 cubic inch, 400 hp + nitrous, the Interceptor has 1100 hp. This makes it the unique 60’s classic hypercar for power-to-weight, at 821 hp per tonne. The Bugatti Vyron is 522 hp per tonne and the Super Sport 622 hp per tonne. So the Lightweight Racing Interceptor is a unique classic hypercar, that has more power-to-weight than the Bugatti. Unique and hypercar powerful and most importantly, one-of-one, the only original Lightweight Racing manual Interceptor. Without nitrous the 800 hp engine gives the car a better than 597 bhp per ton better than the Bugatti Vyron, the 21st Century hypercar.
The present owner bought the Lightweight Racing Interceptor as it was a one-of-one only car. It has the chassis number 116/2875. 116 denotes the manual cars (115 is the chassis number of the automatic cars), 2875 was the only one of the 23 RHD manual cars that had no power steering, air conditioning… with weight reduction – the Lightweight Racing Interceptor,a 440 cubic inch engine, alloy wheels and louvred glass fibre bonnet with battery in the trunk.
All European 60’s classic cars, had at most 300 hp; E Types 200 hp (net) 265 (SAE); similar to the Aston Martin DB:4, 5 and 6’s straight six. Only Jensens and Monteverdi 375’s had Chrysler 440 375 hp engines. Only these engines can be stroked and uprated to over 1000 hp with nitrous. The Ford 427 side oiler, as found in the AC Cobra Mk2 and Ford GT40 7 litre; produced 410 hp (net); 480 hp (net) (in the race GT40 with Holman Moody heads) respectively.
The most valuable one-of-one only American/European classic car is the Carol Shelly’s personal Cobra Super Snake CSX 3015. One of only 23 427 competition roadsters built, CSX was hot rodded by Shelby in 1967. Fitted with a pair of ball-drive Paxton superchargers, on a dual-quad 427, backed up with a C6 Ford auto gearbox, the other 427 Shelby was crashed after Bill Cosby sold it on. That makes the 3015 a one-of-one car. It was sold at Barret-Jackson in January 2007 at Scottsdale, Arizona for $5.5 million. The supercharged 427 made around 512 – 550 hp (net). As the C6 in standard form uses 60hp and probably has a high stall converter, the Shelby automatic gearbox probably uses 100 hp, dropping horsepower at the wheels to 412 – 450 hp. All Cobra’s weigh in at 2626 lb. In giving the $5.5 million Cobra a power to weight ratio of around 350 – 384 horsepower per ton. This is the second most powerful 60’s roadcar, in terms of power to weight ratio. The most powerful is the Lightweight Racing Interceptor, having a manual gearbox (that does not have an automatic gearbox using 100 hp just to work) and 1100 hp. Giving a 821 hp per tonne. As a one-of-one classic hypercar, the most powerful original engined + make, 60’s roadcar, the Lightweight Racing Interceptor is a blue chip investment for the serious collector.
The car has 1100 bhp and 821 hp per ton with the race cut-outs on the exhausts opened full, 1080 bhp for the road on closed exhaust.
The other super expensive Chrysler roadcar is the one-of-one Monteverdi HAI (shark) powered by a 426 cubic inch hp Hemi. This is an early 70’s car. Worth $17 million dollars plus. Two Monteverdi HAI’s built from parts are in the Swiss Monteverdi museum. This is the most expensive one-of-one classic 70’s roadcar. Powered by Chrysler. So one can see Chrysler engined cars have immense value if one-of-one cars. The Lightweight Racing manual Interceptor is Chrysler powered and a one-of-one only. It is all original, having the Hemi A833 4 speed Chrysler manual gearbox and a Salisbury 2.88 to one (unique to manual cars) back axle, mated to the 493 cubic inch Chrysler engine. The 440 Chrysler came out in 1967, so like the Hemi, are the true supercar engines of the 1960’s. Both the Hemi and RB (raised block) 440 engine have the largest deck height of 10.725 inches; so can be stroked up to 540 cubic inches. The Ford 427 and Chevrolet 427 have a lower deck height, so cannot be stroked to the same extent as the Chryslers of the 1960’s. In the 70’s Ford and Chevrolet caught up with the Ford 460 and Chevy 454. Chrysler has the perfect big bore, short stroke of a race motor.
Jensens in general are valuable, but not spectacularly so. But the one-of-one only Lightweight Racing Interceptor is vastly valuable, as it is the unique classic roadcar, hypercar, of the 1960’s. The most powerful 60’s classic roadster. As any investor will tell you the unique, most powerful, original, hypercar of the 60’s is a blue-chip investment. That is why the present owner bought it 30 years ago. Now due to emigrating from Britain to retire, the owner is offering this unique investment opportunity to the serious collector. The one-of-one Lightweight Racing Interceptor, most powerful classic hypercar will make the perfect centre piece of the serious collector’s car collection: making it the most prestigious collection in the world by having the most powerful one-of-one 60’s roadcar with 1080 hp. Closed exhaust 1100 hp + with open race exhausts.
There are a number of companies restoring American and European muscle-cars and classic cars respectively. Prices for Mustangs, Cudas and Cameros can be as high as $350,000; for restored, super powerful clones of muscle-cars. Mustangs generally have 427 aluminium after market engines that make up to 725 hp with twin Paxton super-chargers. Cudas generally have the Indy Hemi that in 528 cubic inch trim is 591 hp 641 lb ft of torque. Cameros have the 572 cubic inch after market Chevy engine rated at 620 hp and 650 lb ft of torque. These are all aftermarket non-original engines. The Eagle E Type uses the 4.2 straight six engine stroked to 4.7 litres and producing 300 hp. This is using the original E-Type Jaguar engine. Cost of these cars is £250,000 to £500,000. The Mk 3 automatic Jenson Interceptor is also sold as the Interceptor R with a Chevy 6.2 litre Corvette engine, auto box and uprated suspension for £117,000. Thousands of Interceptors were built with Mk 3 auto transmission, so the non-unique cars benchmark the price of Interceptors with 429 hp after market Chevy engines. Special resto-rods can be up to $1000,000 in the states; built as unique cars for the rich and famous. So the cost spread for non-original common 60’s cars, is from $350,000 – $1000,000, for fully built, US muscle car clones with high horsepower.
The one-of-one Lightweight Racing Interceptor is unique and has a 800 hp 800 lb/ft torque 493 Chrysler engine, using the original Interceptor 440 block+rocker covers. An original unique one-of-one car with an original Interceptor engine. Hemi Cudas have sold at auction recently for $400,000, a convertible for over $1 million dollars. No one-of-one car has appeared on the market recently. This one-of-one hypercar is an investor’s dream car for it is original, has cachet and has been out of the loop for 30 years. Like the Shelby Cobra Super Snake CSX 3015 the Lightweight Racing Interceptor has been factory race uprated, some of the extensive race uprated features are:-
Ram air induction in a special unique fibreglass hood adds 40 hp
Raised port racing cylinder heads, fully ported.
Race Blueprinting of the 493 Chrysler engine by top British funny car engine builder.
Roller camshaft so the engine can spin to 8000 rpm.
Raised RB block in as original Interceptor, strengthened with a stud girdle.
Raised capacity from 440 cubic inches to 493 cubic inches.
Race rods, H beam, 7.1 inches in length for maximum rod/stroke ratio.
Race carb, 1000 HP Holley custom tuned by the engine builder.
Race engine internals, all forged to take 1100 hp.
Race cooling system with custom aluminium radiator to take 1100 hp.
Race oiling system, Hemi pickup and high volume pump and pan.
Race suspension, special double lever front shocks, coil over shocks at rear.
Race brake calipers to uprate original Dunlop disc breaks.
Race fuel system, two Holley G rotor high volume 150 gallon pumps, and original fuel tank modified for racing with internal baffles.
Race nitrous system, controllable power upration from 100 – 300 hp. Set on 300 hp.
Race wheels, original 60’s Wolfrace 7in x 15 in dish-mags.
Race ignition MSD 7AL and MSD retard box for Nitrous Oxide sytem.
Race uprated Hemi A833 original Chrysler manual box.
Race exhaust, custom 3 inch large bore stainless steel twin exhaust.
Race exhaust cut-outs electronically controlled for open partial or closed exhaust system.
Race exhaust crossover to add 25 hp to engine output.
Race carbspacer to add 20 hp to engine output.
Race dual plane, max wedge port manifold, to boost low end end torque, and high rpm horsepower.
Race profiled standard port heads to enable the engine to idle at 800 rpm, and have power and torque from fast velocity in ports at low rpm.
Roadcar designed engine for 680 lb ft of torque from low rpm, off idle to >800 lb ft at 5200 rpm, to give a flat plateau-like torque curve for acceleration, all facilitated by the special methanol/water injection system.
All aftermarket naturally aspirated engines have a single plane, big port head, so don’t make power under 3000 rpm. The Interceptor race engine behaves like a standard 440 Interceptor. It idles at 800 rpm and makes power off idle with, power at 1000 rpm upwards; the carb spacer enables the dual plane to make power all the way to 7000 rpm. So the car idles in traffic, can be driven in town, the clutch engaging at 7.5 mph for ease of use. The standard original gearbox and back axle enable 200 mph at 8000 rpm. So the car is fully race uprated for the track or autobahn. It is easy to put a high-power intractable engine in any car, that can only be used on the track. Or use a 5 speed gearbox with 4.11 or lower back axle, and a 9 inch rear end. The Interceptor came with a 3.07 back axle. The Lightweight Racing Interceptor had a special 2.88 Salisbury limited slip differential, mated to the 4 speed A833 Chrysler box, uprated with hydraulic racing clutch assembly. First gear is 2.88 ratio enabling first gear 0-60 mph for maximum acceleration. Fourth gear is a 1:1 ratio for maximum top speed. A special Jensen race setup for the street – all original and fully rebuilt to the highest standard, by a top high performance car builder who has restored GT40’s and built many race cars.
Compare this with the as an E-Type for £600,000 shown on BBC2 Top Gear 16/4 which has the aluminium 6 cylinder 305 hp (SAE) type engine; Shelly 350 GT Mustangs with the 4.7 litre, 289 cubic inch 306 (SAE) horsepower, 347 lb/ft (SAE) cars cost $150,000 – $220,000, one example advertised at $898,000. Both cars compete for the premier 60’s sports car, yet none can compete with the Jensen Lightweight super competition manual Interceptor, thus making it extremely valuable, especially since it is a one-of-one hypercar. The Lightweight Racing Interceptor makes the E-Type and the Shelly 350 GT Mustang look pedestrian; their 0-60mph being around 7.6 second, 6 second respectively; while with drag slicks the Lightweight Racing manual Interceptor will do 0-60mph in the 2 second range.
As far as modified Interceptor’s go, the Interceptor R with the 429 hp 6.2 litre Chevrolet engine sells for £117,000. A V-10 Chrysler Viper engined MK3 Jensen Interceptor has been advertised on eBay for £125,000 and sold. This car had 630 hp (advertised ). The Lightweight Racing Interceptors 440 engine (now 493) makes 800 hp without nitrous. With nitrous the car makes 1100 hp – all original.
For the serious collector the car also has the original glass fibre louvered (non ram air) bonnet. To fit the original bonnet (hood) the inlet manifold and carb can be changed to the original dual low profile dual plane manifold, the car originally had when the owner bought it in 1981. The dual quad manifold has been specially ported by Hughes Engines in the USA; the carbs uprated to twin 750 CFM Edelbrock vacuum secondary carbs. The linkage is like the Hemi. The car runs on the rear carbs, twin chokes, then the front carbs, front two chokes, then the vacuum opens the chokes on the front and back carbs. This Hemi style carburation fits easily under the original Lightweight Racing bonnet (hood) and so enables the car to make 960 hp with nitrous. It is not ram air, so loses power due to heated air entering the carbs, but since the car has water/methanol injection the air entering the cab is cooled by the methanol/water to add 10 – 20% to the engine. So the collector has the original glass fibre bonnet/and dual quads for show time and the ram air race glassfibre bonnet and 1000 hp big dual plane manifold for maximum power on the road or track. The best of both worlds. The car comes with both bonnets and the dual quad setup (boxed as new), the car having on it the 1100 hp Holley Carb and max wedge dual plane, with ram air bonnet. The buyer can specify he wants the glassfibre bonnet and dual quads put on the car and the glassfibre race ram air setup taken off (to be shipped with the car for racing.) This will only be done after the car is bought to stop time wasters. It means the collector can have the glass fibre dual quad set up when the car is in his collection, on show. A simple manifold and carb swap, with the ram air bonnet and he can go racing or drive it fast on unlimited roads like an autobahn, or the Arizona road race… No other Jensen Interceptor had a factory fitted glass fibre bonnet only the Lightweight Racing Interceptor. The original owner got Jensens to put on dual quads to emulate the 300 Chryslers series that had the 405 hp dual quad engines in the 300G, Hand F 413 cubic inch super fast saloons of the 60’s. The inline dual quad setup gives the Lightweight Racing Interceptor 375 CFM to cruise on and up to 1500 CFM for all out racing, provides good fuel economy and lots of power; as well as fitting under the louvered glass fibre bonnet (hood) to impress the people who can’t afford the premier 60’s hypercar – the Interceptor.
The dual quad setup was on the 413 (343 hp (SAE)) Chrysler engines in the Facel Vega manual cars with the Pont a Mousson 4 speed gearbox; the dual dual quad setup on the Lightweight Racing Interceptor is in perfect keeping with the period and the vehicle. Facel Vegas are big heavy 4000lb saloons. The 3000lb Lightweight Racing Interceptor with dual quad engine, emulates the twin quad setup on the super Competition Cobras with their 427 cubic inch Ford; as well as the Shelly GT500 Mustang with it’s dual quad 428 police Interceptor engine. Having both a race setup, with the 1000 CFM Holley hp and the classic car dual quad setup, both on dual plane manifolds, offers the collector the best of both worlds. He has a vehicle that is period like the manual Facal Vega, Shelby GT500, Super Competition AC Cobras, Hemi Chryslers such as the Hemi and Cuda, the Baldwin motion and Yenko (all with dual quad) 427 cubic inch Cameros. Jensen Motors fitted the Lightweight Racing Interceptor with a 375 hp 440 Chrysler engine; I am told, the first owner added a dual quad setup from a 413 300 series Chrysler The dual plane dual quad manifold that came with the car enables the collector to emulate the carburation of this period; this time with two 750 CFM Edelbrock carburettors to provide carburation to the 493 solid roller cammed nitrous methanol/water injected motor, all in keeping with the period.
Unique aspects of the Lightweight Racing Interceptor are:- no power steering; found on all other manual cars making: the only one of the 23 without any option; like the L88 Corvette No air conditioning; almost all the 23 other RHD manual cars had air conditioning.
No soundproofing; all other manual cars were soundproofed as they were luxury grand pourers, not racing cars, like the Lightweight Racing Interceptor.
No spare wheel assembly; as the Lightweight Racing Interceptor was a road going race car; like the GT500 Shelby Mustang. A unique louvered glass fibre bonnet (hood) to take 100 pounds of weight off the front of the car, with an aluminium box, in the boot for the battery.
Double lever shock front suspension, not the single shock arms lever setup of the other manual cars and normal Interceptors MK ones A retrofitted 440 cubic inch 375 hp (SAE) Chrysler RB engine with dual quads. All the other manuals had 383 engines from the passenger car division. The 440 was a Police Interceptor engine and had high 10.5 to 1 compression and big valve 906 Heads.
Wolfrace dishmags; 7×15 inch aluminium wheels; not the steel Rostyle wheels of all the other 23 manual cars… were similar to the Wolfrace wheels found on the 7 manual AC Fruas 428 cars, that now command such a high premium. The 7×15 inch Wolfrace wheel was ultra rare, as it was intended for race tyres in the 1960’s period. The 2 spare Wolfrace wheels can be bought with the vehicle for an extra £3000 per wheel, if the collector wants 2 spare wheels for larger width track tyres, without the hassle of changing tyres on rims. The car has an aluminium bell housing, uprated hydraulic clutch and servo. The manual clutch on the normal manual cars was very heavy; not usable for racing. So the owner had the clutch system uprated for smooth pedal action. The car has a custom built aluminium radiator with uprated dual 11 inch fans and cooling needed for a high power race motor. The radiator is an exact copy of the original manual down-flow radiator (available with the car as well) that was in all manual cars.
Carburation is dual quad as discussed or for racing a 1000 Holley, with glassfibre race ram air hood, raised plenum. Both car use the 300 hp sequential nitrous system that comes in gradually with time to stop the tyres disintegrating under 1100 hp. The car has the rare turquoise leather hide interior not found in other manual cars or automatics in general. The colour favoured by Aston Martin cars of the 1960’s and 1970’s. The car has a special uprated Hemi A833 Chrysler manual box and special high performance propshaft with the 2.88 Salisbury limited slip differential not found in automatics but found on the SP 440 six pack Chrysler auto saloons. The rear suspension has coil over shocks not found on the standard manual cars, which used Armstrong Selecteride shocks.
The car has a lower stance than normal cars to provide race handling in a 1960’s vehicle, all other Interceptors have a higher ride height.
The Lightweight Race Interceptor has custom 1 7/8 inch exhaust silver coloured headers,. ceramic coated, not found on any other Interceptor due to the difficulty in making and fitting them.
The Lightweight Race Interceptor has a unique 3.5 collector linked to 3 inch stainless steel twin exhaust system; with a crossover pipe to add 25 hp to output by balancing exhaust flow, in left and right banks of cylinders.
As an investment the car is the only Jensen manual factory modified one-of-one Lightweight Racing Interceptor; that is the most powerful naturally aspirated original engined, 60’s classic car; 800 hp (net) 1100 with nitrous, to emulate the Eleanor 60’s Shelby GT 500; makes this classic hypercar equal in value to the Shelby Super Snake CSX 3015. Like the Shelby Cobra the Lightweight Racing Interceptor is one-of-one of 23 manual cars made. The Lightweight Racing Interceptor has more power from its naturally aspirated Chrysler engine, than the Shelby Cobra’s, 427 Ford with Paxton superchargers; it is also a manual so doesn’t suffer the huge power losses of a C6 Ford autobox with high stall converter. As the car has been out of sight for 30 years, it is a unique investment opportunity. The owner is not in a rush to sell, so the highest bid, by phone or email, will purchase the classic hypercar. As Mk111 Interceptors with Chevy L56 429 hp motors start at £117,000 from Interceptor R/S, starting bids should mirror this.
The original Chrysler 906 heads, fully ported, with 2.2 inlet valves and 1.81 exhaust valves, that were originally on the 440 engine, are available for an extra £7500. They fit on the 493 engine without problems; giving a 10.2 compression ratio and significant loss of horsepower, 100+, as compared to the aluminium race heads, now on the car. They are offered for completeness, so the collector has all the significant engine parts, if he wishes. The 906 heads go perfectly with the dual quad setup. The heads flowing 290 CFM, at 600 lift, which matches the ported dual quad manifold that flows 290 – 310 CFM; with the plenum dividers machined off an extra 30 hp is added; manifold flow should then be 307 – 327 CFM. This gives the serious collector all the options to maximising his investment. The 906 headed engine producing 600 – 650 hp.
Special Lightweight Features:
Manual Jensen Interceptors all had Austin Westminster lever shock type front suspensions, like the 10 manual Jensen CV8’s built. They all weighed in at 3500 lb. The Lightweight Racing Interceptor was lightened by:- 7×15 inch aluminium Wolfrace wheels, instead of Roystyle steel wheels, which were only 4.5×15 inch on the normal manuals. The weight saving was 50 lb.
No spare wheel or assembly, saving another 50 lb.
No soundproofing or padding, saving another 100 lb.
No air conditioning, saving 100 lb.
No power steering assembly, saving 25 lb.
No auto radiator (auto MK1’s weighed 3500 lb) saving 25 lb.
No automatic bell housing, saving 25 lb.
No automatic gearbox assembly, saving 25 lb.
A custom glassfibre bonnet, saving 75 lb.
An aluminium radiator, saving 25 lb.
Total weight saving approximately 500 lb.
So the Lightweight Racing Interceptor weighs approximately 3000 lb (the above figures are rough estimates)
This gives approximately a power to weight ratio of 821 hp (net) per tonne. (non metric ton) with the 1100 hp manual water injected nitrous motor. With original 906 heads, under the original bonnet with nitrous injection we have 709 hp (net) per ton (non metric). Even without nitrous the car has a 597 hp per ton, better than the Bugatti Vyron. Not bad for a 1968 class Hypercar (figures approximate).
Body: All new panels added by owner after he purchased it in 1981. A recent restoration has replaced the entire undersection of the car to take the 1100 hp, using 18 gauge steel, but leaving it totally original. The panels are as the owner replaced from 1990’s. Car was originally chocolate and brown, now the Brienz Blue seen in the Argos advert on UK television. All the new underbody work is meticulously captured in picture form by the owner.
Block: 30 thou over Chrysler 440 block.
Crank: Forged, 4.15 inch stroke.
Rods: H Beam, 7.1 inch long.
Pistons: Custom forged.
Rings: chrome Moly file to fit rings.
Stud Girdle: Hughes Engines stud girdle to reinforce main caps for 1100 hp.
Heads: Victor aluminium heads, fully ported (standard port), flow > 370 CFM at high lift).
Inlet Manifold: Indy Dual Plane max wedge hybrid, fully ported.
Alternative: Edebrock Dual Quad fully ported.
Carburation: Holley 1000 hp with double downleg boosters.
-alternative: Dual Edelbrock 750 CFM vacuum secondaries.
Camshaft: Solid Roller Com Cams custom grind: power band: idle to 6500 rpm for classic car use (can be uprated to bigger Cam for more power)
Head Gasket: Felpro 60 thou with Chemetic 0.38 gasket compression ratio is raised to 11.2 to 1.
Compression ratio: 10.6 to 1 or 11.2 to 1 (gives extra 30 hp).
Ignition timing: 38.5 degrees advance.
Capacity: 493 cubic inches, 8.06 litres.
Rod stroke ratio: 1.71.
Oiling system: Milodon 7 quart with 0.5 inch Hemi pick up, windage tray to add 15 hp and internal baffles to stop oil surge.
Oil pump: High volume, Milodon.
Water pump: high volume.
Headers: Custom 1.78 inch into a 3.5 inch collector.
Exhaust system: 3 inch stainless steel with crossover pipe to add 25 hp to engine output by balancing exhaust pipes.
Nitrous kit: 300 hp Zeks nitrous, custom polished bottle; MSD Retard Box; Edelbrock nitrous controller unit, with microswitch cab bracket.
Fuel system: Dual Holley G Rotor 125 gallon per minute, dual line setup, with return to original tank. (Modified with internal baffles for racing)
Starter: lightweight high power.
Roller Timing Chain: Double roller timing chain with Torrington bearing, Indy cast front cover and roller cam assembly.
Cam driven bronze distributor drive.
Glassfibre race bonnet hood with Ram air induction to add 5% to dyno horsepower.
Carb Spacer integrated with Nitrous induction to add 15 hp.
Exhaust crossover to add 25 hp to dyno horsepower.
Total output with classic car cam 800 hp.
With racing cam of 651 inlet 650 exhaust; 263 inlet duration, 270 exhaust duration at 50 thou lift, on a 108 lobe seperation, another 40 hp+ is added to the engine, with loss of low speed tractability to give 840 hp.
For circuit racing a Comp Cams 657I 659E 275, 282 duration at 50 thou, on a 108 lobe seperation is recommended by 440Source.com. This should give 860 hp.
The cars shorter duration cam is perfect for everyday city use and gives the best low rpm torque and horsepower, as well as acceleration from 0 to 60 mph. The only limit to the classic hypercar’s performance is the all original drivetrain with:-
Back axle: Salisbury limited slip differential 2.88 to 1.
Gearbox: A833 Chrysler 4 speed. 1st gear 2.66. 4th gear 1.
Wheels: Original 60’s Wolfrace 7×15 inch with
Tyres: 225/55/15 VR for street use.
Clutch: Centreforce with hydraulic clutch uprated for ease of use, with special hydraulic assembly custom machined.
The original tyre setup cannot put down 1100 hp, but enlarging with wheel tubs the rear arches devalues the car, so the car will wheelspin in all gears at full power. Larger tyes can be fitted on the 7 inch rims if necessary, probably 245/50/VR15’s.
The engine was built by the UK’s premier funny car engine builder. His wife drives their 3000 hp methanol powered Hemi supercharged funny car to 6 second dead, quarter miles. He blueprinted and custom built the 493 Chrysler. It was dyno tested and run in on a 850 CFM Barry Grant Carb that made 610 hp and 610 torque at 5800 rpm, 4600 rpm respective on a vacuum secondary carb with no spacer. So the engine can make good mileage with even a small vacuum secondary carb as found on normal Jensen Interceptors; all of which (except the SP) come with 850 CFM vacuum secondary carburettors. With ram air, carb spacer and ram air, the standard Jensen Interceptor J Series carburation of 850 vacuum secondary can make 680 hp for very good gas mileage and total originality. The 440 with dual plane manifold and 850 vacuum secondary carb in the base Interceptor engine makes 284 hp, found in Mk3 cars.
Unique Features of the Lightweight Racing Interceptor.
1. Large diameter unique wood and alloy steering wheel, to complement the non power assisted steering rack. All other manual Jensen Interceptors had small diameter vinyl steering wheels to go with their power assisted rack and pinion boulevard cruiser specification.
2. Unique torquoise hide interior with turquoise leather seats, the so called special hide option.
3. Headrests to support the neck of the driver for fast road racing.
4. Choke assembly in the dash to open and close the manual choke carbs fitted to the Lightweight Racing Interceptor. All other Jensen Interceptors had automatic choke Carter carburettors.
5. No spare wheel assembly. As a road going race car weight was at a premium. All the regular Interceptors had a spare wheel under the boot (trunk) floor: held there by a steel assembly. The Lightweight Racing Interceptor has an aluminium smooth boot (trunk); devoid of the hole in the boot (trunk) and the associated screw assembly to hold the spare wheel in place.
6. Unique 17×15 inch alloy wheels. The dishmags originally had radial ER70’s as seen on the MK111 E-Type. All other 68 and earlier cars plus 69 MK1 Interceptors had steel Rostyle wheels, 4.5×15 inch, as well as Dunlop high speed crossply tyres or 185×15 radials.
7. Double cylinder lever shocks on the front suspension to uprate the front suspension. The standard Interceptor of MK1 had single cylinder lever shocks.
8. A 440 Chrysler engine fitted by the factor to replace the 383 Chrysler engine shortly after it was built at the owners behest. The engine was a 375 hp high compression single carburated high performance version of the 440. The same engine found in Monteverdi 375 of that time…
9. An under-bonnet ram air assembly modified from the MK1 Interceptor air cleaner housing, which had dual snorkels and tubes that ran to pipes above the radiator to feed cold air into the 440 engine. This kept the engine cool. It also increased power by 5% due to ram air and cooled air being denser than hot under-bonnet air. The original air cleaner box is still with the parts available with the car. It was custom made by Jensens to fit the car.
10. Special 3 inch exhaust sytem with crossover to complement the high power 375 hp Chrysler and increase power due to the exhaust crossover balancing exhaust pulses.
11. The Armstrong Selecterides were changed to heavy duty shocks, later to coil over shocks.
12. Lowered suspension to make the Lightweight Racing Interceptor handle at speed and not wallow like the regular luxury cruiser Interceptors.
13. No soundproofing to reduce the weight of the car.
14. No bulkhead foil and soundproofing to let the big 440 engine lose more heat to the steel of the vehicle and reduce weight.
15. Custom made fibreglass louvred bonnet with 22 lourvres to reduce the front weight of the Lightweight Racing Interceptor and cool the engine bay at idle; needed with the big 440 Chrysler 375 hp. No other Interceptor was fitted by the factory with a glassfibre bonnet. The bonnet (hood) is a very sturdy glassfibre bonnet (hood) to take the stresses of racing. Jensen used the design for their MK111 steel Interceptor bonnets (hoods) in 1972.
16. The Chrysler 440 had special ported 906 heads fitted with big valves by Jensen Motors Ltd to boost the power of the big engined Lightweight Racing Interceptor. These are available with the car for an extra £7500 for the cylinder heads.
17. The engine was fitted by Jensen Motors with a mechanical camshaft to allow the big 440 hp to rev above 6000 rpm to 65000 rpm. The vehicle now has a solid roller camshaft to allow it to rev to 8000+ rpm.
18. The bottom of the block was opened to accept a 0.5 inch Hemi pickup by Jensen Motors Ltd and had a deep pan oil sump.
The engine was rumoured to develop 550 hp (SAE) with a Holley carb on the dual plane manifold after Jensen Motors Ltd finished the rebuild for the owner. It now develops 1100 hp to make it the most powerful original engined naturally aspirated 60’s classic car in the world. The engine comes with full build sheets from the engine builder plus run in dyno and 1000 hp Holley dyno sheets; for the serious collector. It has the original V5 document held by the current owner since 1981. It can be shipped at the buyers expense to any location in the world. It must be insured for shipping, paid for by the new owner. All trucking to and from the ports is at the owners expense. Payment must be by wire transfer, which will be arranged by phone or email. As you can see this car is a one-of-a-kind, one-of-one classic; the hypercar of it’s day and will only appreciate in value with time.
As it is so valuable bids will be accepted above £117,000 and the highest bid will buy the car. This may take some time so the collector who has to have this Lightweight Racing Interceptor in a hurry should have deep pockets and pay an order of magnitude or more to guarantee a quick sale.
Methanol Water Injection:
The Lightweight Racing Interceptor is fitted with a methanol water: 50:50 injection system to add 70 hp to the 493 cubic inch Chrysler engine; as well as to gaurantee the engine does not detonate, when used with the nitrous oxide injection system. As the methanol : water mix sprayed into the air cleaner hat cools intake temperature by 100F and for every 7F decrease in temperature, power increases by 1% the system can boost horsepower by 14%.
With compression raised by changing the thick 50 thou Felpro gasket for a chemetic 0.38 thou or lower gasket, compression can be raised to 11 or 11.2 to 1 and still use lots of advance. The engine uses 38.5 degrees of advance, without injection, so there is lots of scope for more advance at the 10.6 compression ratio or to keep 38.5 at 11.2 to 1 with a gasket change. The Victor heads can be milled to 12 to 1 as the methanol : water injector raises the octane value of 91 octane to 116 octane; or using super unleaded 96 octane to 121 octane. The original 906 heads are 79.5 cc and with a low profile chemetic gasket can give 10.9 to 1. Using the methanolol water injection system the engine produces 800 hp and 926 hp with nitrous oxide. Upgrading the compression ratio of the engine to 11.2 to 1 and a bigger cam can add 70 hp to the engine to give 1170 hp, or 12.5 to 1 mandates use of the methanol water injection all the time but can add 140 hp to produce 1240 hp, to beat the Vyron (Bugatti) Supersport and give the 882 hp per ton power to weight ratio. Change the cam to a sport profile Comp Cams custom grind 0.686 intake; 0.640 exhaust lift; 252 258 duration at 50 thou lift and you get another 40 horsepower at little expense to low rpm driveability; to raise horsepower to 1140 hp and 851 hp per ton. The 906 heads on the engine will give 650 hp easily and with nitrous 950 hp for an exact 60’s engine specification engine. It is up to the new owner to choose what to do; the car is sold with the 1100 hp engine as standard.
Race Uprated Breaking System:
The original Dunlop disc breaking system has been uprated with Aftermarket brake calipers to boost breaking response. The original single pad Dunlop system was not capable of stopping a high powered car. For originality the Dunlop discs are original equipment and their large surface area is up to braking a high power car with Coopercaft 4 pot aftermarket brake calipers. To further boost breaking efficiency an electric vacuum pump has been added to the braking system to maximise the vacuum that activates the brakes now braking is super servo assisted. All Jensen Interceptors had a vacuum reservoir in one of the chassis’s tubes, that now is kept at low pressure constantly by the aftermarket vacuum pump. This race uprated braking system is the best available on original MK1 Jensen Interceptors and means the The Lightweight Racing Interceptor will stop like a modern sports car.
The Lightweight Racing Interceptor parts:
The owner has collected unique or add on parts for sale. These include:
The original fibreglass louvred bonnet originally fitted to the The Lightweight Racing Interceptor. The owner took this off and stored it as it was totally unique and non replaceable. Jensen Motors Ltd made it specially for the car. For 30 years the owner drove the car with a steel bonnect (see pictures), so if it was damaged the steel bonnet could be easily replaced from second hand steel bonnets. The originial The Lightweight Racing Interceptor bonnet (hood) made from fibreglass to the same standard as a Martin Robey aftermarket bonnet, but totally unique to the car is available with the car for an extra £15,000.
The owner has two extra 7×15 inch original aluminium wheels supplied with the The Lightweight Racing Interceptor, so the original owner could replace the rear wheels with big racing tyres as a pair when racing. These 1960’s Dishmag wheels are unique and not available anywhere in the world for love or money. The car comes with 4 of these 7×15 Dishmag aluminium wheels. The serious collector may want 2 spare wheels in the 7×15 inch aluminium Dishmag to match the 4 on the car. These 2 spare aluminium one-of-a-kind Dishmags as supplied by Jensen Motors Ltd specially for the The Lightweight Racing Interceptor are for sale with the car for £6,000 the pair.
The 440 engine originally had 906 Chrysler cylinder heads. These were fully ported and have 2.20 inlet valves; 1.81 exhaust valves with bronze valve guides and hardened valve seats. They flow 290 CFM at high lift and will make 600 hp in a 12.5 compression ratio engine. A serious collector may wish to have these to go with the car. They are available for £7,500 the pair.
To match the 906 cylinder heads is a specially ported dual plane manifold that flows 290 CFM to 310 CFM after being fully ported by Hughes Engines. With the plenum dividers machined off the inlet manifold will flow 305 CFM to 325 CFM. Two 750 CFM Edelbrock vacuum secondary carburettors to match the manifold with the progressive linkage and twin quad air cleaner complete the induction system that will fit under the glassfibre original bonnet (hood). The entire induction system is available for £1500.
Race Uprated Suspension:
The front suspension has Sorbothane bushings to race uprate the original front suspension to aid the car’s handling. The double lever shocks give race upration to the front shock absorbers and are original equipment on the The Lightweight Racing Interceptor. The rear suspension has leaf springs race uprated with coil springs on the shock absorbers and a custom built special Panhard rod to hold the back end on the tarmac when applying over 1100 horsepower to the back wheels. Both front and rear suspension has been totally rebuilt and uprated as well as the back axle (photos available)
The Knowledge: Valuation:-
The “Top Gear” programme on BBC2; 24/7/11 repeated on 27/7/11; number 5 of 6 episodes; had Jeremy Clarkson road test an Interceptor R. This was a common and garden MK3 Jensen Interceptor which weighs at around 4000 lb. The car had had it’s Chrysler engine changed for a 6.2 Cheverolet LS6 small block with 429 horsepower (net). It’s back axle was changed to a Jaguar IRS. It had uprated breaks and a large bore exhaust on the LS6 exhaust manifolds and a Cheverolet style automatic box. Performance as Jeremy Clarkson noted was very quick 0 to 60 mph in 4.5 seconds, top speed 167 mph. Cost was £117,000.
The one-of-one The Lightweight Racing Interceptor has an original Chrysler 8.06 litre engine, producing over 1100 hp. The car is totally original and powered by an Interceptor engine, not a Cheverolet. Instead of weighing in at 4000 lb it weighs around 3000 lb. Power to weight ratio for the Intercepor R is 240 horsepower-per-ton. For the The Lightweight Racing Interceptor 821 horsepower-per-ton. So if the The Lightweight Racing Interceptor was a clone, a normal MK1 automatic which had it’s engine and gearbox changed to a 440 and a manual A833, it would be 821/240 times more expensive or 3.42 x £117,000 = £400,000 (approximately).
As the The Lightweight Racing Interceptor is an original one-of-one car it’s value is an order of magnitude higher than £400,000 or £4 million. Since it is the most powerful 60’s classic car on the planet in terms of power to weight ratio (at least outside the USA); this adds value to the £4 million estimate of its’ worth; since it is the pinnacle of 60’s classic cars; equivalent to the Monteverdi HAI that has an eight figure value. So any sum above eight figures is possible as its’ resale value in the future. The car has been unavailable for 30 years and once bought will be snapped up by a rich collector, disappearing from the other collectors like: Jay Leno, the Sultan of Brunai… for another generation. This means it’s value is inestimable. To this end the car will be sold to the highest bidder, starting at a reserve price of £117,000 and continuing upwards till the owner has got the maximum value available.
Comparing the The Lightweight Racing Interceptor at 821 hp/ton with the Bugatti Vyron Supersport with 1180 hp and 622 hp/ton at 2 million euros (exchange rates on 2/8/11); one can see the The Lightweight Racing Interceptor is probably worth £1.75 million pounds sterling or more, if it was one of many. Not one-of-one only and unique the Audi/VW corporation is building hundreds of Vyrons and 100 Supersport Vyrons. The Lightweight Racing Interceptor is a one-of-one car and gives the collector who buys it the unique most powerful 60’s hypercar on the planet for his collection. It may be therefore argued that £1.75 million pounds is under pricing The Lightweight Racing Interceptor, as it cannot be duplicated. More importantly the collector is unlikely to sell it for another decade or more because of its unique one-of-one heritage and the kudos it gives to any collection thus raising it’s value to the level of the Shelly Super Competition Super Snake at £3.44 million or more.
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Value as a Historic Racer:
September – October’s edition of Classic Cr and Sports Car had a Lightweight Racing Pantera, De Toraso GTS (1972) with a 565 hp Chevel and Ford Engine (12.5 to 1 plus race motor), advertised for 450,000 euros. This was a 1 of 4 built Lightweight Racing Panteras. The unique Lightweight Racing Interceptor is a one-of-one and has 800 hp in street trim, that can be driven in heavy traffic, (unlike the Lightweight Racing Pantera) 1100 hp with nitrous oxide. If the Lightweight Racing Interceptor engine was converted to full race specification the following changes could be made:-
Compression raised to 12.5 to 1 by skimming the race heads.
Charging the water/Methanol injection from manifold boost activated to permenantly on, with a 12 volt cut out to stop the ignition if it runs out of fluid. This would enable the 12.5 to 1 race motor to run on super unleaded on the street.
Opening the ports to the heads to Max Wedge specifications that slows intake velocity by one half, so hurts street performance but enables the heads to flow 375 CAM at 700 lift, for racing, giving 825 hp without ram air and water/Methanol injection and 900 hp with the ram air, water/Methanol injection for circuit racing.
Charging the intake manifold to a Max Wedge single plane, such as the Indy manifold that flows 500+ CFM.
Charging the cam to a 700 lift 290 duration out 550 solid roller, for historic racing only.
The engine would then give 900+ for historic racing only, 1200+ with nitrous oxide.
Valueing the car from the Lightweight Racing Pantera, another American engined classic car; valued at 450,000 Euros giving 565 hp, the 1100 hp Lightweight Racing Interceptor is worth at a minimum 640,000 Euros, if one takes it’s power out at 800 hp (non nitrous oxide boosted, 880,000 Euros, with nitrous. As the Pantera is 1 of 14, the Interceptor is unique one-of-one so worth 14 times more, or 12.2 million Euros or 10.8 million pounds. So the investment value of purchasing the car is huge, as the owner will accept 2.3 million pounds sterling to secure the car without lengthy bidding.
Value is added to the Lightweight Racing Interceptor as it is a valid Historic Race Car which can be used for historic racing, hill climbs and speed events, such as the Brighton Speed Trials. Powered by a genuine Jensen Interceptor engine tuned to produce over 800 hp in street trim, 1100 hp with nitrous oxide, the car has a 578 bhp/ton power to weight ratio in racing trim, with an ultra mil camshaft for inner city driveability. Like the 426 Hemi Super Stock racers, the Lightweight Racing Interceptor has exhaust cutouts to add 20 hp + to the cars 780 hp1100 hp with nitrous oxide injection, for acing or speed trials. The 3 inch exhaust has a 3.5 inch exhaust cutout with electrically operated baffles to allow, at the flick of a switch, the exhaust to be opened for racing, from the luxury of the driving seat. Open exhausts add plenty of power and torque, but, more importantly, they make the Lightweight Racing Interceptor a street legal Historic Race Car, like the Ford GT40’s or Super competition Cobras, thus adding value to the Lightweight Racing Interceptor: to put it into the million pound plus category of a 427 Ford FT40 with Holman (what word here?) heads. Unlike the Ford 427 GT4 which only has 480 hp, the Lightweight Racing Interceptor has 1100+ hp in a 3100 lb car, dwarfing the power to weight ratio of the Ford 427 GT40. As the Ford 427 GT40s are valued between 1-2 million pounds, one can see the value of the one-of-one Lightweight Racing Interceptor is at the very least, equal if not more to the 1-2 million pound value of the GT40 Ford race cars.
Value always comes from being unique, the one-of-one hypercar of the 60’s, so the Lightweight Racing Interceptor is arguably the most valuable 60’s race car and definitely the most valuable street car of the 1960’s. This enables the potential buyer to see the Lightweight Racing Interceptor as an investment like gold; something that will only go up in value because of its rarity. Another Lightweight Racing Interceptor does not exist, as this was the only manual Interceptor with no options 440 cubic inch engine, allow wheels, glass fibre bonnet, battery in the trunk (boot) and no spare wheel assembly, with no soundproofing, power steering, with Bugatti Vyran supersports costing 2 million euros having 1180 hp in a 4000 lb car and the new 700 hp Zonda costing 1 million euros; the unique one-of-one 1100 hp Lightweight Racing Interceptor with a 3100 lb racing weight can be seen as a one-of-a-kind investment when measured up against the Bugatti and Zandra. It wont break or corner like the 21st Century hypercars but will beat them in a straight line. More importantly as it is a one off, it will go up and up in value with time as it is the only 60’s hypercar that can measure up to the Bugatti and Zonda: with it’s original 440 Chrysler engine in normal aspirated, unsupercharged, form. It also is a very placid street able racing engine giving power from it’s 800 rpm idle. The Bugatti is turbo charged, the Zonda a high rpm screamer. The Lightweight Racing Interceptor is superior in (what the hell is that word really!) torque to the (is that EI?) Zonda, and lighter by 900 lb to the E2 Bugatti. It adds cachet to any serious collection and is most importantly a one-of-a-kind.
The car has been unmodified having all original brakes, suspension, engine and gearbox. But all the mechanicals have been race uprated.
Suspension: race uprated with plyurethane bushes and coil over rear shocks.
Brakes: have Coopercraft 4 part calipers = vacuum pump to aid braking.
Engine: original 440 Chrysler box race uprated
Gearbox: original A833, Chrysler manual with after market centreforce clutch and uprated hydraulic clutch assembly added to original manual clutch in alloy bell housing.
Battery: is in boot (trunk) unlike all other Jensens in special alloy case. Jensen motor company moved the batter to the boot (trunk) when they retrofitted the 440 Chrysler engine in the 60’s.
This is the only Interceptor to have full length 1 and seven eights tube headers that swing forward then back to give the full length to all exhaust tubes, to go into a 3.5 collector, 3 inch exhaust and 3 inch electronically graduated cutouts.
The car is all original just race uprated.
The market for high end classic cars of prestigious and rare makes is strong both in the USA and Europe. Russian and Arab millionaires now look for top of the market real estate, classic cars, yauhts and businesses. With inflation losing the value of flat currently, sound money has fed to tangible things like gold, commodities, high end: mansions and classic cars. The Lightweight Racing Interceptor is a one-of-one unique 60’s hypercar. Outside of the USA the Lightweight Racing Interceptor stands as the most power original engined make classic car of the 1960’s. Chrysler 440 cars of the 60’s can be replicated to produce the power of the Interceptor but the (what word here??) body cars are 4400 lb and the A body Barracudas and Dodge Darts were made in the tens of thousands.
In Europe the Ferrari 250 GTO’s, Aston Martin D4’s 5’s and 6’s and Lambourghini Miura’s struggled to produce over 300 hp net. The Lightweight Racing Interceptor produces 1100 hp and will drive in heavy traffic. In full race trim the Interceptor can make 1220 hp+. Only 23 RHD manual cars were built. The ILHD manual car was a heavy weight with power steering and aircon and has been reducted to a Vin plate and have chassis, most of it’s original parts lot forever. This made the IRHD Lightweight Racing Interceptor the undisputed rarity of the Jensen motor cars. Added to its premier position as the most powerful 1960’s classic car, having 1100 hp and its total orgininality, being in the same owner’s hands for 30 years: the unique glassfibre hood, allow road wheels, 440 engine, wooden steering wheel, Hemi A833 gearbox and rack and steering assembly being still with the original vehicle, co,pletes the rarity package for the serious collector. Name of these pieces are available now so a duplicate car cannot be made. Martin Roley’s do not have any 15×7 inch Wolfrace wheels, the fibreglass louvred bonnet, gearbox parts, steering assembly, propshaft (a special to the Lightweight Racing Interceptor, manual gearbox, radiator, battery in trunk assembly or unique turquoise hide trim interior; all of which makes this vehicle a one-of-a-kind. Added to the state-of-the-art race upration of all the hypercars mechanicals, but keeping their originality, makes the Lightweight Racing Interceptor a very sound investment.
Photos of the Interceptor prior to its total restoration of 2011. Note the steel bonnet used to protect the original glass fibre louvered bonnet that was kept in storage while the car was driven, see picture of glass fibre bonnet. The car will be identical to this except it will have a full race glass fibre bonnet with 4 inch ram air scoop and headrests on the turquoise leather seats. The body has been totally rebuilt to take the power and all body misalignment corrected during the £60,000 rebuild.