REFLECTOR: No oil pressure

[Scott Derrick]

Went to the airport fully intending to pull the pan.  The A&P/IA that 
supervised the rebuild suggested we fill the oil pump and turn it through.

So as I poured oil into the outlet of the oil pump he turned the engine 
backwards.  We poured in about a quart.

then prelubed the main channels again but this time we pumped until the 
oil came out the oil filter outlet. Then screwed on the filter and 
pumped another quart in.

grounded the mags and turned the engine through with the starter. Showed 
20 PSI on a mechanical gauge we had hooked up to one of the pressure 
outlets.

reinstalled the plugs, started the engine and immediately had 85 psi at 
800 rpm.

stopped the engine after a couple minutes because the plug in the crank 
was leaking a bit.

I don't think any damage was done as the main channels were pre-oiled on 
both prior 20-30 second runs. But I will certainly look hard at the oil 
filter which I am going to pull on the next visit to the airport.

Scott

Chuck wrote:
> Scott, when we were building race engines, we would never start them until 
> the entire system was primed (lines, oil filter, pump, oil coolers, etc) and 
> produced oil pressure. These were very expensive motors like your turbo 520. 
> You can use a cheap pulse type fuel pump tapped into the oil system to fill 
> everything. Next we cranked the engine with the spark plugs removed to 
> ensure oil pressure, and finally fired the engine.
> 
> It takes very little running without oil pressure to score the rod bearings 
> which can result in broken rod or crank, especially in a turbocharged 
> engine. After you run it for testing, I'd send in an oil sample before I 
> flew it to be sure your don't have excessive bearing metal. I'd also replace 
> and cut open the old oil filter to look for metal.
> 
> I don't mean this to sound like the end of the world, but this could be very 
> serious. Hope you find nothing.
> 
> Chuck H
> 
> 
>>> From: "Scott Derrick" <scott at tnstaafl.net>
>>> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
>>> Sent: Wednesday, September 05, 2007 9:10 AM
>>> Subject: Re: REFLECTOR: Chevy numbers
>>>
>>>
>>>> Had a bummer happen yesterday.
>>>>
>>>> First start of my TSIO520 went well after a few false attempts.  She
>>>> sounded good but the oil pressure never came up after about 30 seconds.
>>>> Put a mechanical gauge on a pressure outlet, Re primed the engine with
>>>> oil and tried again. No joy.
>>>>
>>>> I could see the mechanical tach output turning when I rotated the prop.
>>>> Its driven by the main oil pump impeller.  So the oil pump is turning.
>>>>
>>>> removed the oil filter, it was dry!!!
>>>>
>>>> pulling the pan today to check the sump.  If that reveals nothing will
>>>> inspect the pressure relief valve.  After that I'll have to pull the
>>>> engine off the firewall to remove the oil pump....
>>>>
>>>> Scott
> 
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
> 
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
> 

-- 

-
     I would rather be exposed to the inconveniences attending too much 
liberty than to those attending too small a degree of it.

     Thomas Jefferson to Archibald Stuart, 1791. ME 8:276