In <199511141513.PAA03132@sauron.thlogic.com>, Jeremy DuBois wrote:
> Yes, I agree. The question becomes: how much power does it take to drive
>the pump, and is it a noticable amount? If you gain 1/8 a horsepower, it
>hardly seems worth it for the added emmisions (for street uses, obviously,
>racing is different).
> I took the pump off my Spitfire and didn't notice any difference, but I've
>had people argue that they did it on their cars and it made a lot of
>difference. Again, I think scientific evidence is needed.
>
A bit off the subject, but still the same thread.... Someone recently
commented that the air-injected heads were _stronger_ because of the
cast-in bosses. Sorry, not my experience, nor that of many others.
The cast-in bosses are drilled, which sets up stress points that make
the heads extremely prone to cracking. In my own experience I have
handled three air-injected heads and all three were cracked, usually
around the #2 cylinder spark plug hole. At least with my '73, doing
away with the air injection had more to do with getting a solid head
than with removing the power loss due to the pump. I have heard
similar stories from several parts dealers as well.
A. B. Bonds, whose head is not cracked
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