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Re: 4 threaded holes in block-what are they for?

To: BarrMark262@aol.com, mgs@autox.team.net
Subject: Re: 4 threaded holes in block-what are they for?
From: Barney Gaylord <barneymg@MGAguru.com>
Date: Sat, 14 Feb 2004 20:55:48 -0600
At 09:19 PM 2/14/04 -0500, BarrMark262@aol.com wrote:
>.... My 74B .... there are four threaded holes (7/16 by 20 pitch) located 
>just above the spark plugs but below the top of the block. .... tell me 
>what I should do about them. ....

These are air injection ports for emissions controlled vehicles 1968 and 
later.  The small holes go directly into the exhaust ports, just above the 
valve heads.  In the absence of the air injection pump and air distribution 
rail, these ports should be plugged.  Any 7/16-20 screw can be used as a 
plug.  Short hex head bolts can work.  Socket head set screws long enough 
to fit flush will look better.

Barney Gaylord
1958 MGA with an attitude
http://MGAguru.com





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