Posted May 27, 201212 yr comment_391277 P/U a whole engine yesterday from a 77-78 280z, the head is a N47 with steel liners.Is there anyway to remove those liners without destroying the head?From my first look it seems that the valve guide is the only thing holding that sleeve in. Link to comment https://www.classiczcars.com/forums/topic/43352-n47-head/ Share on other sites More sharing options...
May 28, 201212 yr comment_391278 Everything I have read stetes that it is not worth the effort and damage risk of removing the liners, and that any gain in flow is questionable, or negligible at best. Link to comment https://www.classiczcars.com/forums/topic/43352-n47-head/#findComment-391278 Share on other sites More sharing options...
May 28, 201212 yr comment_391312 The liners aren't that restrictive, if at all. I wouldn't mess with them. I run P79 heads with liners.....I don't notice any difference whatsoever. Link to comment https://www.classiczcars.com/forums/topic/43352-n47-head/#findComment-391312 Share on other sites More sharing options...
May 29, 201212 yr comment_391389 +1 Leave them alone. Link to comment https://www.classiczcars.com/forums/topic/43352-n47-head/#findComment-391389 Share on other sites More sharing options...
May 29, 201212 yr comment_391392 I have seen ~4 heads with cracks in-line with the location where the runners are anchored into the head. My speculation is these cracks result from thermal cycling of the steel and aluminum and their different thermal expansion rates. Or, from overheating (high exhaust gas temp) and their different thermal expansion rates. Nothing you can do about it. Link to comment https://www.classiczcars.com/forums/topic/43352-n47-head/#findComment-391392 Share on other sites More sharing options...
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