Quote:
the best head to use-A15, A14, or A12 and what are the benifits or disadvantages of each
Even though this is an old question, it is still an often asked question. A basic answer is in our Tech article "
Cylinder Heads Overview".
* 1981-1982 engines in USA used the "emissions" H95 head. This is probably the most common head to find on an A15 in USA. This head was used by A12A/A14/A15. It is an excellent mid-RPM design with low emissions and good fuel economy. But certainly not a maximum HP design, which is obtained with higher RPM.
It also has the largest combustion chamber of an A-series cylinder head, for lowest compression ratio. Although the pistons normally used with it kept the compression to 8.5:1.
* 1980 A15 used the typical A14 oval-port head (80 hp @ 6000 RPM)
* MPG A15 use the round-port A14 head (67 HP at 5600 RPM)
I know this doesn't touch on the turbo aspect, but hopefully it will help clear up some of the confusion around A15 engines.
Transfer
