Is there really a difference in the flow between a '55-'56 and '51-'54 Twin H Intake?

50C8DAN

I have been looking at both the early Twin H and the latter Hash Twin H and the only real difference I can see between them is the early has an external balance tube and the latter has it internal.  I have always heard the early was a superior design and the later design was modified due to the inability to adjust valves in the Nash body.  So is there really an internal difference that matters?

bob ward

There is no internal difference that matters.
The 308 with Twin H was too wide for the Hash engine bay which was designed without the 308 in mind. The internal balance tube manifold is narrower than the earlier variety and was a necessary mod to get the engine to fit.

50C8DAN

thanks Bob that is what I was starting to believe after looking at all the photos I have of the two types.

ratlee2

Both will fit in a 53 Hornet if you use the exhaust manifold from the same year as the manifold.  I have a 55 motor with twin H in my Hornet now.  Other than a slight modification to head pipe where  it meets the exhaust manifold, the fit is good.

50C8DAN

Not concerned about the exhaust.  I will be using a 55 - 56 Twin H as the starting point for the new manifold design.  There will not be a heat riser connection to the exhaust manifold for the new design, it will be hot water heated.