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Another Valve Guide Question

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dcarlg

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So I'm confused. Again. My cylinder head is getting bronze valve guides, etc.
My Workshop Manual section A.19 has a diagram showing valve guide installation height .875" +.00, -.016 above the head.
But the General Data section for BT7 thru BJ8 lists Valve guide fitted height above head: Inlet = 1.348", Exhaust = 1.036"
What do I tell the Machine shop?
Thanks.
Douglas
 
You can give that info to your machine shop his general information, but a good engine builder can calculate the clearances needed with respect to cam lift and rocker ratio and machine appropriate clearances for rocker-to-valve guide clearance. As an example, many hot rod builders will want to use Vortex Heads on the Chevy small block engine build. But most Vortex heads advertise that you should not use a cam with them that has much more than about .480 lift. If you want to use a higher lift cam, you are directed to machine the vortex valve guides for more clearance.
 
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