Inlet Manifolds

Recent development has recently encompassed a detailed look at the manifolds available for side draught carbs. The steel inlet manifolds available have long been acclaimed the very best, out-performing all the alloy types by far. After flow-testing a number of randomly picked steel manifolds, the results showed that as a rule they did not meet their expectations and varied - considerably in some cases - from one port to the other on the same manifolds. Despite this they were still superior to the other manifolds available.

Having set a base-line of data we have designed an alloy manifold that out-flows the steel ones, is extremely consistent port to port, and greatly reduces port-biasing of the mixture. The results were as follows:-

                  Steel      Mini Mania
    3.75"      116.2       116.8
    6.00"      116.6       117.4

The manifolds tested were all unsettled, in fact the alloy ones were straight out of the casting box. We tidied up very slightly the short manifold to see what happened, and the flow went up to 117.2CFM. That is another benefit of the alloy manifold, there is scope for modifications to increase flow even further. We expect the flow figures to be higher on the finish machined manifolds.

The Cast manifolds come complete with rose- jointed linkage mounted directly to the manifold to eliminate flexing. The low line of the linkage makes it ideal for Sprite or Midget applications.

CAST MANIFOLDS:
C-AHT772
3¾" Long 40/45/48 DCOE/DHLA.

C-AHT773
5" Long 40/45/48 DCOE/DHLA.

C-AHT774
6" Long 40/45/48 DCOE/DHLA.

Also stocked are the steel Maniflow manifolds:

C-AHT775
Split Weber manifolds, 3¾" long, upswept.

C-AHT776
45 DCOE/DHLA, 5" long.

C-AHT776A
45 DCOE/DHLA, 7" long.

C-AHT777
45 DCOE/DHLA, 3½” long.

C-AHT778
48 DCOE/DHLA, 3½” long.

C-AHT779
48 DCOE/DHLA, 5" long.

C-AHT780
48 DCOE/DHLA, 7" long.

C-AEG490
HS4/6 twin SU manifold. Narrow balance pipe.

Two types of steel formed inlet manifolds are available for the Arden 8 port alloy head.

C-AHT507
For twin 45 DCOE/DHLA side draught carbs for racing.

C-AHT508
For twin 40 DCOE side draught carbs for road use.

We have produced our own range of cast alloy manifolds for the many SU applications covering the ‘A’ series. The single SU manifolds are developed to give maximum airflow and gas speed yet fit all engines even if the standard air cleaner set up is used -without requiring massive bulkhead alterations and speedo cable re-routing. The as-cast finish provides maximum fuel atomization.

C-AHT770
Takes 1 1/2" and 1 3/4" carbs, HS or HIF type. Medium sized port runners suit all small bore engines irrespective of state of tune, and large bore engines up to fast road spec (dependent on head inlet port size).

C-AHT771
Takes 1 1/2" and 1 3/4" carbs, HS or HIF type. Really designed for 1 3/4". It has large port runners for use on extensively modified heads on big bore engines (1380cc and over).

Both have water heating facility ( 1/2" tube).

The twin SU manifolds have been carefully produced to minimize cross-port-flow interference caused by the balance tube, and have good radii in all the right places. Further blending can be carried out if required, but leave a ground finish to promote, fuel atomization. DO NOT POLISH!

C-AEG488
H2/ HS2/ H4 Manifold.

C-AEG489
HS4/ HS6 Manifold.