When I saw those brand new Amal Pre-monoblocs I was hoping they would be a good choice for my twin carb head. I liked the vintage presentation and was hoping the new models would perform well. It looks like they would be OK in some parts of the throttle range (idle to wide open) but not all so I am now in the hunt for the Premiums. Just like Trev 1st recommended.
Here is what an Amal carb tech replied in an email to me when I asked him to compare the two carbs with reference to the Monobloc as well:
Dear Steve
In my personal view the Mark 1 Concentric is the superior road carburetter. Because the design of the slide causes it to form a ?roof? to the venturi as it rises the pickup tends to be crisper and more immediate which makes for a noticeably pleasanter ride (especially on the ?twisties?). Carburetters with a ?jet block? design such as the Pre-Monobloc and Monobloc tend to be more efficient at speed and indeed the Concentric gives away 2 or 3bhp at maximum torque compared with a Monobloc. However this would be difficult to detect on a road machine which is rarely used flat out.
The Premier carburetter uses a new design of pilot jet which was intended to improve idling and pickup further and also be removable , allowing full access to the interior of the carburetter for cleaning (which is becoming more necessary with modern fuels, especially in the US. Customers report that they are able to achieve slower and more reliable idling with the Premiers and also report improved fuel consumption. There is an article here about using the new carburetters on a Triumph twin:
http://www.amalcarb.co.uk/News.aspx?id=56 The Premiers also use the Stay-up puncture proof floats and a new aluminium needle valve which improves control of the fuel flow. To date no-one has reported any wear on the hard anodised slides which are more resistant to wear and smoother working than any other slide material. The pilot jets are available in different sizes for tuning.
Kind regards,
Phil Beresford
Technical Sales Co-ordinator
Burlen Fuel Systems Limited - The SU and AMAL Carburetter Companies
Spitfire House, Castle Road, Salisbury, Wiltshire. SP1 3SA
Tel: +44 (0)1722 412500 Fax: +44 (0)1722 334221 Email: customer.services@burlen.co.uk Website:
http://www.burlen.co.uk
