All,
If I had the money I would have the aluminium head for the weigh saving alone
and not just weight saved for its own sake but high up and right over the
front wheels just where you don't want it.
Aluminium runs cooler than iron and like for like can run a higher
compression ratio which is either gas mileage or power. I think have a whole
number
maybe more.
The Aluminium heads are all from Pearce no matter who sells them. Maybe some
folk buy a bare casting from Pearce and grind it themselves.
The aluminium head has bigger ports from stock, possibly massivly bigger and
I would expect that on a standard engine this is detrimental to performance
but on an engine that has a cam with something like 290/300 duration it would
pay off. Pearce copied some of the features of the APT iron modified heads
that
they built into their aluminium head.
As far as I know, a modified aluminium head would equal or out peform an iron
head but as with all these things no-one including Pearce has any flowbench
figures for Aluminium heads.
Note all the above is for the A-series head, for the B-series head the
arguments for the aluminium are weaker.
Also, the above doesn't include comment on the Mini Spares aluminium 8 port
head which may or may not be as good as the Pearce head. And don't forget the
16 valve aluminum heads from KAD and Jack Knight.
Daniel1312
In a message dated 25/08/03 02:36:39 !!!First Boot!!!,
pixelsmith@gerardsgarage.com writes:
>
> Hey Cap'n,
>
> I don't know where you get your numbers from to make this claim, but
> I have recently heard from an extremely knowledgeable and well known
> source that the aluminum head does NOT flow as good as a stock cast
> iron head and that if the extra money spent on the aluminum head
> invested in even mild porting of a stock head with Rimflow valves
> would perform much better. I only recently heard this and was
> surprised myself, but the credibility of this individual I think is
> without question. If you have some factual data to back up your
> claim, I'd like to hear about it.
>
> Gerard
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