->>
->> 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
->>
->
-> Hmmm... Interesting. Lindsay Porter, in his MGB Resto book, claims the
->air injected heads are stronger, I believe based on the advice of the
->machine shop he was using. (Its in the section about boring the engine
out
->to 2 liters if you want to check it out).
->
-> Jeremy DuBois
->
Lindsay Porter was referring to a head that was cast for the injectors but
not machined for them ... IOW the same casting was used for all markets
and heads fitted for export to the US were machined for the injectors others
were not ... the additonal metal in the casting (not removed by machining
for the injectors) provides the additional strength.
Larry Unger ---> ungerl@reston.unisysgsg.com
'62 MGA
'72 MGB/GT
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