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                           TeamGrumman-List Digest Archive
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                     Total Messages Posted Fri 02/17/06: 1
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Today's Message Index:
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     1. 01:59 PM - Lifters and a sucked valve.  (TeamGrumman@aol.com)
 
 
 
________________________________  Message 1  _____________________________________


Time: 01:59:11 PM PST US
From: TeamGrumman@aol.com
Subject: TeamGrumman-List: Lifters and a sucked valve.

--> TeamGrumman-List message posted by: TeamGrumman@aol.com

There may or may not be a correlation, but ...

I had a customer experience a sucked valve and had to land away from home.   
I went over and replaced the cylinder.   When I removed the lifters to clean 
and bleed them for a good dry tappet clearance, I noticed they were really 
badly varished and carboned up.   They were, in fact, stuck in their bores.   

>From my early hot rodding days, we would set the clearances on solid lifters 
a little tighter to try and get another few thouandths of an inch of lift.   
This old guy at a Phillips 66 station (remember those?) told us we'd burn the 
valves because the valve sitting on the valve seat is what transferrred the 
heat to the cylinder.   

If what we're experiencing with morning sickness (sticking valves) is the 
lifter sticking in it's bore, it would be worth investigating the condition of

the lifters and the dry tappet clearance. 

On that note:   With 120 STOH on my plane, I pulled all of the lifters, bled 
them, reinstalled then and checked the dry tappet clearance.   They all had 
changed some (all were less), some more than others.   That's to be expected 
with new valves.   I reset them all (mixed and matched rockers and push rods) 
until I got about 0.050 to 0.065 inch clearance on all tappets.   I went on the

high side with the exhaust valves - just in case.   

Gary
PS, I contend (and have for 20 years now) that all Lycs need a top overhaul 
at 1000 hours.   I will now add that doing a dry tappet cleaning and 
re-clearancing at 500 hours would be worth the aggravation.