How to remove jugs from heads? |
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How to remove jugs from heads? |
tornik550 |
Sep 24 2011, 09:12 AM
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#1
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Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
I have never had this issue before. I have new AMC heads and new EMW 96mm clyinders. I assembled the longblock to check valve train geometry. I need to send my heads off to get the valve guide bosses cut however I cannot remove the jugs from the heads. I do not want to break any fins so I haven't tried much other than muscle.
Any ideas? Attached image(s) |
HAM Inc |
Sep 25 2011, 07:54 AM
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#2
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Senior Member Group: Members Posts: 846 Joined: 24-July 06 From: Watkinsville,GA Member No.: 6,499 Region Association: None |
This could be traced to sagging case spigots. The cylinders are tilting and when the head was torqued down it wedged the leaning cylinder into the head registers.
I have observed the spigot sag as well as variations in the bore centers of cases and heads by as much as .005" in both directions. If you are using 1.7 amc heads that have been bored for 96 cylinders and they were bored on a bore center that is off from the case bore center then that would explain it as well. The nominal bore center is 4.897" The cheap easy fix is to bore the head registers larger (typically another ~.005" will do) to allow the jugs to settle into position. Typical register size is 105.0-105.1mm |
tornik550 |
Sep 25 2011, 08:13 AM
Post
#3
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Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
This could be traced to sagging case spigots. The cylinders are tilting and when the head was torqued down it wedged the leaning cylinder into the head registers. I have observed the spigot sag as well as variations in the bore centers of cases and heads by as much as .005" in both directions. If you are using 1.7 amc heads that have been bored for 96 cylinders and they were bored on a bore center that is off from the case bore center then that would explain it as well. The nominal bore center is 4.897" The cheap easy fix is to bore the head registers larger (typically another ~.005" will do) to allow the jugs to settle into position. Typical register size is 105.0-105.1mm Excellent info! I'm sending Everything out to get them checked. I have to send everything out anyways so no big deal (for once). |
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