Following on from an e-mail to the Jensen list, the question was asked about fitting Edelbrock performance parts during an engine rebuild or upgrade. The following is a few tips regarding the equipment.

Edelbrock is by no means the only manufacturer of performance parts out there, but the original mail asked about Edelbrock, and as we have used their carbs and manifolds on the Monday club cars, we will stick them for the main part, but will also add other parts that are available.

Carbs

Any original, or high mileage replacement carb on your Jensen will probably be in poor condition, which will cause poor starting, rough idling, poor fuel consumption, and a lack of performance. There are rebuild kits which are ok to freshen up a relatively new carb, but the throttle spindles on my original Thermoquad were worn and in allowing air, causing all the problems listed above. A rebuild kit will NOT cure this. If you are experiencing any of the problems mentioned, it may be time to look at a brand new carb.

There are 2 ranges, and several models of Edelbrock carb to choose from. The Performer range are good reliable carbs for standard road use (I have one on 136-8779), and the Thunder series is similar but with more features for high performance applications. Both come in manual or electric choke.

The manual versions seem to be jetted rich for performance, and the electric lean for economy. Both can be re-jetted to be either lean or rich depending on your preference. My electric choke 1411 carb is now jetted rich for performance.

The general consensus is the 383ci, and standard 440ci engine need a 650cfm (Cubic Feet per Minute) carb, and that going to larger carbs can reduce throttle response and increase fuel consumption. Highly tuned 440ci engines may need the extra breathing of a 750cfm carb.

Edelbrock now list them by cam duration, which may be a better method of working out what will suit you best.

https://www.edelbrock.com/shop/carburetors.html

Follow the link below for the calibration kits.

https://www.edelbrock.com/shop/carburetors/carburetor-accessories.html?product_list_limit=30

Inlet Manifolds

Edelbrock make a range of manifolds, but the Torker and Victor range are VERY high performance models, and may not work very well on a car used for moderate driving.

The Performer range is more suited to the type of driving (most!) Jensen's are used, the "Performer" and the "Performer RPM"

 

 The Performer is a street manifold giving power from idle to 5500rpm.

 http://www.edelbrock.com/automotive_new/mc/manifolds/chrysler_bb_perf.shtml

The Performer Plus is a "Hot" street manifold giving power from 1500 to 6500rpm.

https://www.edelbrock.com/shop/intake-manifolds.htmlhttp:/www.edelbrock.com/automotive_new/mc/manifolds/chrysler_bb_perf-rpm.shtml

The big concern is the height of the RPM manifold under the bonnet, and is not sure if it will actually fit. Does anyone know?

Cams

Edelbrock make kits of matched components. This way you can avaoid buying a cam which is unsuited to the inlet manifold, etc.

Edelbrock make a "Performer" power kit, which includes heads, cam, manifolds

  etc. This may take the guess work out of what you are looking for.

Here is some basic cam information for Chrysler engines

 

http://www.edelbrock.com/automotive_new/mc/valvetrain/valvetrain_main.shtml

 

Summit is one supplier, but there are others you might want to try.

 

http://www.hughesengines.com/

 

http://www.jegs.com

 

http://www.manciniracing.com/

 

Headers

Headers would be a great addition to that setup, but finding ones that will

fit the Edelbrock heads, and in the tight space of the Interceptor engine

bay is another matter. It can be very difficult to get the Carb (or fuel

injection) setup with the Edelbrock heads as the flow so much air. Hughes do

polished and ported iron heads for about $800, which are good for 500bhp,

without the setup problems, and "Block Hugger" exhaust manifolds will fit.

Exhaust

The standard exhaust on the Interceptor is quite restrictive, with a large reduction in pipe size in the section over the rear axle. Big bore versions are available from Jensen suppliers, but a good exhaust shop should be able to make you one. A balance pipe would also be a good addition to smooth out the idle and release more power.