Kirk Cowen wrote:
> If you have an mga head, throw it away and install a stock 1800 head.
> Grind the edges of the stock intake manifold to let it flow better.
All depends on which 'A' head. The 'A' 1622 head is identical to the
early 'B' (18G to 18GK) head ... IOW, the 'B' used the 'A' 1622 head.
The 'A' 1489 and 1588 heads are another story ... the late 'A'/early 'B'
head would provide larger valves and improved porting *but* has a 43cc
combustion chamber ... so you will have to remove approximately .045
for the late 'A'/ early 'B' head to retain the 1489/1588 38.7cc chamber size
... else you will decrease the compression ratio.
An interesting point ... the increase in capacity from 1489 to 1588
resulted in an increase of power from 68 to 80 ... where as the incease
in capacity from 1588 to 1622 resulted in an increase of power from
80 to 93 ... the increase in power from 1588 to 1622 is out of proportion
to the increase in capacity ... why? ... IMHO, because the 1622 was
fitted with flat top pistons (increasing the CR from 8.3:1 to 8.9:1) and the
head with larger valves and improved porting. IOW, the 1489/1588 engines
should respond nicely to an increase in the CR and the late 'A'/early 'B'
head.
Safety Fast! ... larry.g.unger@lmco.com
'61 MGA 1600 MkII
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