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Old 07-07-2020, 05:36 PM   #5
GOSFAST
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Join Date: May 2010
Location: Long Island, NY
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Default Re: 8ba block decking

Quote:
Originally Posted by mercuryray View Post
I am having an 8ba reconditioned and they have decked the block on the left side and the valve seats are allowing the valves to stick out to far and when I put the head on the valves and the pistons touch the head is there a fix for this. Thanks Mercury Ray.
Hi Ray, sounds like they may have "over-decked" it somewhat!

You should not have to do any "extra" machine work due to milling the decks??

In any event you're going to have to start "hand-fitting" the components on a piece-meal basis! We have on occasion fly-cut the valve pockets, see the photo below, but it was more to work around the chamber volumes.

(Add) Both decks have the same angle and hgt, however, the valves are installed at two different angles from the factory. This explains why they sit at different hgts when in place! If I recall correctly one side is 50*, the other is 53* (nominally).

Thanks, Gary in N.Y.

P.S. Have been milling these Flatheads for some years now on our CNC mill, have never really taken any more than .010" off to get them "flat" and the correct finish?? These decks are "thin" going in, better to leave as much original as possible.
Attached Images
File Type: jpg Flathead Offy Head-Modified.JPG (63.9 KB, 92 views)

Last edited by GOSFAST; 07-08-2020 at 08:07 AM. Reason: Add info
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