Conversion from triple Solex's to Jenvey throttle bodies.

Conversion to throttle bodies.

In this post I have endeavoured to describe the components and other changes required to convert from Solex carburettors to Jenvey Heritage throttle bodies.

Some of this content may have been included in previous posts, however I think it is worth having one specific post specifically for this part of the project.

My feedback to anyone thinking about this is, it's a lot of work! Made doubly difficult if the engine is fitted. For me as the whole car was stripped down it was the ideal time to do it.

Fuel line update

The fuel system changes that are necessary:

• Additional filter, pre low pressure pump
• Fispa regulator is replaced with a swirl pot that has an integral high pressure pump and regulator and filter.
• A return pipe from the swirl pot back to the tank

(note the High Pressure Filter is integral to the Jenvey swirl pot)

Picture shows Swirl pot fitted in place of the Fispa regulator as well as the return fuel line.

The Jenvey EFI swirl pot with integrated high pressure fuel pump and pressure regulator has been designed to convert low pressure fuel from the low-pressure fuel pump to high-pressure fuel for electronic fuel injection. 

It includes an integral 3 bar fuel pressure regulator on the return side. It has been designed to swirl fuel from the low pressure pump and high pressure return ensuring liquid is centrifuged out forcing air into the middle / top of the pot which then escapes via the bleed.   This ensures there is a constant feed of high-pressure fuel to the engine even when the fuel tank level is very low and the low-pressure pump start drawing air. 

Internal baffling and a 60 micron filter built into the internal pump pickup

https://www.jenvey.co.uk/swirl-pot-setup-sytec

Inlet Manifold

The inlet manifold was modified by inserting a baffle between the siamesed ports.

An additional water temperature sensor was added as required by the ECU, allowing the original analogue temp sensor and gauge to continue working as normal.

Engine

During the engine rebuild (Bob Dove Motorsports) a crank trigger wheel was designed, manufactured and fitted. The required sensor was attached to the engine.

List of Sensors

The following sensors were fitted to various parts of the car, none of these are visible to the casual viewer.

• Crank position sensor (see previous paragraph and photos)
• Water coolant temperature  (see earlier paragraph and photos)
• Air intake temperature sensor
• Fuel pressure sensor
• Knock sensor
• Throttle position sensor is built into the Jenvey throttle bodies
• Lambda oxygen sensor

ECU

I used the EMU Classic Black ECU

Wiring loom

The wiring loom was created using a set of colour coded and id printed sleeves from the ECU manufacturer. The design, layout and make up of the loom is quite a task, especially if like me if you have never done it before!!

I added a relay to control a new external electric fan, triggered by the ECU

Clean 12v feed to ECU via relay

Clean feed for Swirl pot via relay

Heritage Throttle Bodies

Jenvey Dynamics, Bridgnorth, WV15 5HP, UK

Dynamo

I wasn't planning to replace the Dynamo, but at start up I did get some interference and guessed it was the Dynamo. I have replaced it with a Dynator for Wosp https://www.wosperformance.co.uk/dynators

Dyno

Now you need to find a good tuner who really knows the ECU of choice, my final run-in and tuning was successfully completed by Page Motor Sport

I ended up with a very smooth power curve and flat torque curve. I did have a small vacuum leak on one of the mounts which probably lost be about 5hp. However with 148hp at the wheels I'm happy.

See the video of of one of the power runs