Vauxhall C20XE 'Redtop' Bike Carb Conversion Kit
danST Engineering are pleased to be able to offer this complete bolt on kit for the Vauxhall Redtop C20XE Engine. The package consists of the following:
1x TIG welded danST Engineering Aluminium inlet Manifold
1x Set of R1 40mm Mikuni Carburettors
1x danST Engineering Carb Fitting Kit (4x Fluoro lined silicone hoses and 8x stainless mikalor clamps) in red, blue or black
A Pipercross PX600 filter kit can be added to this kit for an additional fee if required - please contact for further details.
This kit is ideal for anyone wanting to carry out the popular bike carb modification as an alternative to the old weber twin 40 style conversions. Bike carbs offer excellent performance, reliability and fuel economy when compared to the weber alternatives. These conversions are very popular in both modified and kit car circles and provide a low cost, simple power upgrade not to mention a fantastic soundtrack!
All danST supplied carburettors undergo a comprehensive inspection, strip, ultrasonic clean and rebuild process as required. Every set of carburettors are run on our dedicated test rig to ensure smooth idle and transition to higher RPM (see our youtube channel for running examples). We provide the carbs with base settings (and necessary jets) to allow you to get your engine up and running/driving. However these settings are only approximate and it is therefore essential that the carb jetting is set up by a competent engineer/mechanic using the necessary wide band AFR equipment (ideally on a rolling road) to avoid engine damage.
The manifold is manufactured from high quality aluminium with a precision Water Jet cut 10mm thick flange and TIG welded 45mm (Outside Dia) runners with a 3mm thick wall. All internal joints are fully ported/ground to ensure a smooth flow.
Carbs pictured may not be the exact model but will be in as good or better condition. Buy these now and have your cars performance increased ready for the summer season!
Please Note: All of our carburettor kits are made to order and therefore on a 10 working day lead time. This is to allow for manufacture of the manifold and preparation of the carburettors.
What Else Will I need?
The carburettors in this kit will take care of the fueling of the engine, however you will need a means of running the ignition system and this will likely fall into one of the following categories:
1.1) Distributor Based Engine. If your engine is equipped with a distributor as standard, this will work fine alongside the carbs to run the spark. Some distributor based systems have a vacuum line from the original inlet manifold. This vacuum reference gives additional advance at light throttle openings to aid light throttle response and economy, however many customers making performance upgrades including twin carbs simply opt to leave this line disconnected to simplify the install. If you do wish to retain this advance then our vacuum balance bar product must be fitted to our manifold to provide a stable signal (see our shop). One single tapping into our manifold is not sufficient and will result in a pulsed signal.
1.2) OE Fuel Injection Engine. Depending on the standard management your engine is equipped with it may be possible to retain the standard ECU to run the ignition system. All original sensors and connections should be retained (with the exception of the original fuel injectors) to ensure the ECU has all the necessary inputs. If the ECU has a vacuum feed from the original manifold our balance bar product (see our shop) can be fitted to the new manifold to ensure the ECU retains this load reference. One single tapping into our manifold is not sufficient and will result in a pulsed signal. If the vacuum line is not retained it is likely that the ECU will revert to a basic 2D ignition map similar to running a distributor.
1.3) Standalone Ignition Controller. The ultimate ignition control is of course a standalone 3d mappable ignition controller such as the NODIZ Pro (see our shop for further details). This system replaces the distributor or OE management system entirely and enables full control of the ignition map, allowing maximum power and torque to be achieved at every point in the RPM range. This ECU takes inputs from a crank sensor (this will need to be retro fitted if the engine is not equipped with one as standard) and either a throttle position sensor or manifold pressure (MAP) sensor. See our shop for further details of the NODIZ Pro Ignition Controller.
2) Fuel Supply
Motorcycle carburettors require a fuel supply pressure of 2-3psi. This can be achieved with one of the following:
2.1) Motorcycle Fuel Pump. Our bike fuel pumps are designed specifically to work with the carbs in our kits. They do not require a fuel pressure regulator and are an extremely simple inline install (in and out fuel connections and a 12v supply). Bike pumps should be mounted low down, close to the tank and horizontal. See our shop items for further details on our bike pump kits.
2.2) Aftermarket electric fuel pump and fuel pressure regulator. If you are upgrading from another aftermarket carb setup is is likely that this type of fuel system will already be in place. This can be re-used as long as a 2-3psi supply pressure can be achieved.
2.3) OE EFI Fuel pump and fuel pressure regulator. If the car is equipped with a fuel injection pump as standard the pressure will be considerably greater (typically 45psi+) than the required 2-3psi for the carbs. However there are regulators available that are capable of reducing this pressure sufficiently from EFI to carb requirements.
3) Throttle Linkage. The bike carb cable connection is relatively simple in comparison to other aftermarket carburettors with no complicated linkages required. In most cases it is simply a case of adapting the end of the existing throttle cable (inner and outer) to interface with the carbs. We can supply a universal cable kit that contains all of the parts to adapt an existing cable or make a cable assembly up (see our shop items).
4) Air Filters. It is important to protect your engine from airborn dust and debris and danST Engineering therefore always recommend running with an air filter fitted over our carburettor kits. We can supply a range of Pipercross PX500 and PX600 filters custom made to fit any carburettors used.
5) Rolling Road Tune. Our carburettors are all tested on our test bed and a base set-up carried out. This will ensure that with the carburettors installed your engine will start and drive. However final jetting and set-up must be carried out using the necessary AFR equipment and under real world load conditions (usually on a rolling road). This will ensure the maximum performance is achieved and will avoid engine damage that can be associated with running excessively lean or rich.
What power increase will I see?
Power gains are highly dependent on other work carried out to the engine. As with any induction modifications the carbs will better compliment an engine that has had an exhaust manifold and system upgrade as a minimum. Camshafts and headwork will of course further benefit the power and torque curves. As a rule of thumb expect 10-20bhp gains with our kits on a healthy engine with a good ignition set-up, depending on other modifications.
Please see our shop for accessories that will aid with the above as well as further parts to further compliment your install. Additionally you may wish to consider our range of ‘Deluxe’ carburettor kits as these contain a host of useful accessories – these kits can also be tailored to your requirements. Further advice and technical information is available on the danST Engineering homepage.
Bike carburettor tuning services.
danST Engineering are pleased to be able to offer bike carburettor diagnostic and set-up services using our in house chassis dynamometer (rolling road) based in Shipley, West Yorkshire. Please drop us a message to discuss your requirements.