Subject: Re: compression?
Author: Chuck Stottlemyer
Date: Feb 6, 2004, 7:32 AM
Post ID: 1715968607
Hi, John..
I'm *assuming* the engine hasn't been run for a long time?
Aircraft sit for extended periods, and low compression from leaky valves
is common.
Here's the fix, called "staking the valves"
You have to have a leak down tester, or at least a method of applying 80
psi to the cylinder.
(1) put the cylinder at TDC on the firing stroke.
(2) Apply pressure
(3) Using a copper mallet, or piece of something soft to keep from doing
any damage, rap the rocker arm over each valve several times. This opens
the valve, and lets it slam shut, breaking loose the accumulated
corrosion, carbon, etc. that is holding the valve slightly open. The air
pressure blows it from between the valve and seat.
I've seen engines go from zero compression to less than 10% leakage
using this method.
Better than an overhaul in a can! :)
Cheers!
Chuck in Indiana
98 Centauro
00 Jack-All hack tractor
73 Eldo project
John Sutton wrote:
| Several weeks ago I asked about points, valves and carbs along with several other things and received great advice. I have adjusted everything to spec and realize that my fuel flow sucks so petcocks are next. I got a compression check done and one cylinder is 100 while the other is 130. What does this mean and what must I do? John S. Eldo ------------------------------------------------------------------------ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online <http://us.rd.yahoo.com/evt=22055/*http://taxes.yahoo.com/filing.html> |