REFLECTOR: Engine troubles

gstull at tampabay.rr.com gstull at tampabay.rr.com
Thu Mar 8 06:52:00 CST 2012


Personally I would try to loosen up the intake valves. Squirt a penetrating oil onto the valve stems from the rocker box area. Take a plastic mallet and tap the rocker arms at the top of the valves. If there is rust holding the valves open this may dislodge it. When performing annual inspections, sometimes valves stick causing low compression. This usually helps the valve seat, although it's normally the exhaust valves sticking.  
---- Geoff Gerhardt <geoff at thegerhardts.com> wrote: 
> Some of you might remember a few weeks ago, after taking my first taxi I
> did a full run up and found my static was low.  After doing some
> troubleshooting, I found a couple issues - an intake leak and a faulty
> electronic ignition box.  My Light Speed ignition box is off to Klaus at
> Light Speed Engineering to be fixed.
> 
> During the process of checking the timing/ignition, I noticed that when I
> was trying to find #1 TDC by putting my thumb over the spark plug hole to
> check when it was on a compression stroke, I was not feeling much pressure.
>  So, I recently did a compression check.  The numbers were dismal. All were
> low: #1 - 10/80, #2 - 20/80, #3 - 24/80, #4 - 10/80.  All were leaking
> copiously past the intake valve.  Exhaust valves sounded tight, some
> leakage could be heard past the rings.  I took the intake pipe off #1 and
> put my fingers behind the valve and could feel the air rushing past.  Not
> sure why its so bad.  Looks like the guy who sold it to me (an A&P and
> Velocity owner) is either a terrible A&P or dishonest.
> 
> Can someone tell me my options?  My preference would be to rebuild it
> myself (I've rebuilt many engines, most recently a Porsche 911 - pretty
> similar!), so I'd look forward to it.  The drawback of that is time.  I
> could probably tear it down in day, but I suspect sending stuff out for
> inspection and acquiring all the necessary parts might take awhile.  What
> are my options for the cylinders?  Send the out for rebuild?  New?  How
> much $ are we talking?
> 
> The other option would be to send it to a rebuilder - definitely be more
> expensive, but do they have relatively quick turn around times?
> 
> Geoff



More information about the Reflector mailing list