Modification of "waffle" manifold to suit to IDF 4

[Slawo2000]

Hello Guy,
In the nearest future I would like to replace my IDF¢ž¢s 40 carbs with 44. I use standard 124 Sport …œwaffle‚ manifold and I wonder how to modify it to suit to 44 mm IDF¢ž¢s. Is it enough only to enlarge entry of the manifold as on the attached sketch ? Or should I enlarge ports gradually on their whole length ?
Slawomir

[Guy Croft]

hi Slawomir

what you have proposed is correct and that's what I would do, make sure the exit area of then manifold is same as inlet port and that the cross section of the inlet manifold is constant from exit right up to the 90 deg curvature section.

After boring out for 44s you need to keep the bend radii as big as possible where you blend the downdraft section into the runners.

GC