 Where/What is reference plane- when flycutting heads? |
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| jjs3rd914 |
 May 20 2018, 01:01 PM
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Member  Group: Members Posts: 124 Joined: 8-August 04 From: Sarasota, FL Member No.: 2,476  |
Curiosity question.
When type 4 heads are to be fly-cut for increased compression, where/what plane does the machinist set up on. Videos seem to show the setup is the head being clamped on the valve cover surface to the mill table..... So is that surface suppose to be parallel to the chamber sealing surface?? If so what is acceptable variance across the sealing circle to the valve cover surface. We have measured our new set of 2L head castings and there is up to a .002" variance from on side of the sealing surface to the other with respect to the valve cover surface. So in this case the sealing surface is not parallel (in the same plane) to the valve cover surface? But does is matter as long as the sealing surface itself is flat all the way around to the to the cylinder top and both chambers on each head are in the same plane? Do these heads need touched up? What am I missing here?? Thanks jjs3rd914 |
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| Mark Henry |
May 20 2018, 02:21 PM
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Also to do it right machine the case decks flat.
The case deck is where the cylinder bottoms sit in the case. |
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Posts in this topic
jjs3rd914 Where/What is reference plane- when flycutting heads? May 20 2018, 01:01 PM
Mark Henry Yes, OK, maybe, nothing. :D
.002 is a hair, fl... May 20 2018, 02:16 PM
worn
Also to do it right machine the case decks flat. ... May 20 2018, 02:44 PM
Mark Henry
Also to do it right machine the case decks flat.... May 20 2018, 02:52 PM wndsrfr Hmmmm....maybe clean up the one with the least var... May 21 2018, 05:30 AM jjs3rd914 Interesting discussion. I am learning.
I agree w... May 20 2018, 03:48 PM Mark Henry You can obsess over .0001" but it quickly bec... May 21 2018, 09:05 AM |
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