[f-AA] Short spark plug

[Ian Harvie]

Sound like water injection. It was supposed to have been developed by a 
guy in Australia by the name of Frank Kleinig (spelling) who pulled the 
cylinder heard off his car and found one cylinder to be quite clean. 
there was a small crack in the head allowing water to seep in. It was 
used on early Willys Jeep station wagons in the early fifties I guess.

Ian

Ken Lessard wrote:
> Hello Bill in NH,
>   In regards to your compression loss I would like to offer a past 
> experience I had and maybe it can benefit you . There a several 
> possibilities for the loss of compression, the worst being a cracked 
> exhaust valve or burnt valve seat so I will share mine with you and this 
> group. This is a cut and paste from a topic I responded to on the 
> Aeronca L3 site recently. I only post it here for your consideration and 
> not, by far, a recommendation. It's just something that worked for me a 
> long time ago... I also came up with a way to ream the exhaust valve 
> guide on my friends C-172 with an 0300, that had a history of sticking 
> exhaust valves, without pulling the jug...That’s another story in 
> itself...   Ken in MA
> 
>  "Hi John,
> I was just wondering if you determined where your compression loss
> was coming from during the leak down test. Years ago I had the same
> problem with my C-75 engine in my Ercoupe. My #1 cylinder was 55/80
> and my IA friend suggested that I make a determination where the
> loss was before ripping into the engine. With the cylinder
> pressurized with air I took off the oil cap and listened, no sound
> so the piston and rings are good. Next I put my ear to the carb.
> intake, no sound so the intake valve was good. Lastly I put my ear
> to the exhaust and heard lots of air rushing. Hmmm, seems to be a
> bad exhaust valve. Way back then, the only fuel option was 100ll. 80
> octane was gone and mogas was not legal yet so we had major problems
> with lead deposits in the cooler running cylinders. Now, hang on
> because I'm gonna tell ya what I did to fix it (under direction from
> the IA). I pulled the air filter and cowl and ran the engine up to
> temp. We brought the engine up to 1800 RPM and sprayed atomized
> water into the carb. inlet using a pump type garden sprayer. Very
> little at first and increased the volume of water until the engine
> started to loose RPM. I was stunned to see all the black crap that
> belched out of the exhaust. I did this two times and the second time
> the exhaust was clear. The next compression test #1 was up to 77/80
> and all the cylinders came up to 76/80 to 78/80. I'm not
> recommending this procedure but it sure worked for me. The
> compression stayed up through the next 4 annuals until I sold the
> plane.. Just a thought... Ken"
>  
> 
>     ----- Original Message -----
>     *From:* Bill <mailto:wbeauv at metrocast.net>
>     *To:* aeronca at westmont.edu <mailto:aeronca at westmont.edu>
>     *Sent:* Wednesday, November 01, 2006 5:54 PM
>     *Subject:* [f-AA] Short spark plug
> 
>     Hi.We are doing our annual on Moya (1946 7AC) and the IA I'm working
>     with said I should put the Short plug in the front cylinder.Can
>     someone tell me the numbers for it and a good supplier for an
>     A65.I've got one cylinder reading low (45/80) and we can hear the
>     air coming out the exhaust.The others all read 71/80 and have about
>     500 hours on them.He seems to think the valve is sticking becouse I
>     run mostly pump gas and don't use(sorry to start any wars )
>     MMO.We're going to run the motor to warm it up and check again.Has
>     anyone else ran into this problem before. Thanks. Bill in N.H. 2505E
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