Neil Cotty wrote:
> Out of interest is anyone aware of different size
> inlet valves for the 1600, and the 1600Mk2. My
> valves from my 1600 head measure 1.5" and the valves
> out of the Mk1 B head which I believe to be the same
> as a 1600Mk2 valve measure 1.55" (should be 1.56").
> ... [snip] ...
> I never knew that the valves were smaller on the
> 1600, or do I possibly have a head off a different
> car?? I recently found out my H4 carbs were Magnette
> spec and not MGA so who knows!!!
Nope, correct sizes ... MGA 1500/1600 have 1.5" inlet
valves, and the MGA 1600 MkII/MGB 1800 MkI have 1.56"
inlet valves. FYI ... also a corresponding increase in
the size of the exhaust valves. Can't speak to the
correctness of the casting, but I do know there were
casting differences between the MGA 1500/1600 heads
(that effect performance) and ass*u*me they existed
on the Magnette engines.
The increase in power from the 1588cc to the 1622cc
engine cannot be explained by the 34cc increase in
capacity .... the increase in CR from 8.3:1 to 8.9:1
certainly is a major factor, but IMHO its the increased
valve sizes and flow characteristics of the MGA 1600 MkII
head that makes the difference. You can obtain a rather
larger increase in power on a 1588 at a minimal cost by
fitting 1622 rods and pistons (to increase the CR) and
a 1622/1800 head.
Later ... Larry
'61 MGA 1600 MkII
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