[NSRCA-discussion] engines woes

[Ed Miller]

Anthony;
I believe Joe Zeigenfus had a head crack causing running problems. If you 
find the head cracked after cleaning, I have a stock head.  I assume you are 
using the 10 pitch APC/DL 3 blade so 7800rpm peaked with 20% is in the 
ballpark although a bit lower than I see with my 2 engines.  With my tach I 
get 8150rpm with 20% on the 10 pitch with the AAC setup.  I mentioned to you 
at the Nats about the "O" ring below the carb, replace it with a YS silicone 
"O" ring used on the intake tube to head/intake tube to carb body.  There 
are 2 small "O" rings on the carb spray bar adjustment piece, look at those 
under a magnifying glass to be sure they aren't torn or worn flat. Any 
perceptible play between the wrist pin and piston, wrist pin and con rod and 
con rod and crank pin will cause problems.  Never ran an engine with the 
wrist pin installed backwards to know if it makes a difference but is the 
wrist pin installed with the closed end facing the exhaust port ?? Look for 
an abnormal amount of up and down play of the ring in the ring groove and be 
sure the ring itself hasn't overheated and lost it's tension. Do you have 
another pipe to try ?? It is possible a baffle is dislodged and partially 
blocking the exhaust.  If you had metal in the exhaust from a previous 
problem, some residue may be still in the pipe and burning out the plugs. 
Good luck.... Ed M.
----- Original Message ----- 
From: "Anthony Romano" <anthonyr105 at hotmail.com>
To: <nsrca-discussion at lists.nsrca.org>
Sent: Tuesday, July 25, 2006 5:11 PM
Subject: [NSRCA-discussion] engines woes


> Having some trouble with my RX having an erratic idle and an appetite for
> glow plugs before the Nats. Replace both bearings that seemed perfect, as
> was the rest of the internals, and cleaned some carbon of the piston 
> before
> the Nats. Idled and ran better but was a little tight on the next run. 
> This
> seemed to improve quickly as the bearing seals seated but down on power.
> Got to Muncie and was a bit down on power. After ingesting another plug 
> from
> over twisting the needles I was given a remedial needle valve lesson by 
> Ron
> Lockhart and switched to 30% Nitro. Made it through the Nats without much
> power.
> Today went to back to 20% for the lower heat and made sure I had the 
> needle
> set 7600 rpm launch from a 7800 rpm peak on a pinch. When taxiing it 
> loaded
> up and quit and wouldn't restart. Another new plug and double check the
> needle and made a weak flight. Second flight same thing but this time got 
> it
> restarted without replacing the plug.
> Now here is the interesting part. This engine has always had a lot of fuel
> gooped on the head and header. Today noticed a lot on the bottom of the
> plane. I am thinking either a bad ring or some damage to the crank port or
> the case. Any other ideas?
>
> OS 1.40 RX
> SS bearings
> Aeroslave pipe 25.25 from baffle to plug
> 15.75*10*3 APC
> 20% S&W fuel
> OS type F
>
> Can't afford to change to other power source so any ideas on this one 
> would
> be helpful.
>
> TIA
>
> Anthony
>
>
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