Did you prefill your oil cooler?

I'm getting pretty close to first start and am curious if you guys dumped what I'm guessing to be about a quart into the oil cooler before doing the Lycoming pre-oil procedure?

Or did you following the Lycoming procedure and start cranking it without the plugs until the oil cooler and everything else was filled with oil?

I was also planning on not purging the fuel and oil pressure lines as I hear from many they don't do it and it's not necessary, would love to hear opinions on this one too.

Thanks!

I pre-oiled my cooler prior to first plugs out crank test. At low temps, though, the vernatherm is closed and there won't be any oil flow through the cooler. It's probably debatable whether pre-oiling the cooler is at all useful. I figured it would be good not to have the cooler suck up 1/2 qt + of oil or so when the vernatherm opens if it was dry to start.

I also pre-oiled my engine back through the oil pressure sender line using a modified garden sprayer to pump oil back that direction (great idea learned here on VAF) and reconnected to the oil pressure sensor at the manifold. During the initial plugs out crank, oil pressure came up immediately and stayed stable throughout.

i did the Lycoming procedure, no trouble at all.

be Aware that you have to crank the engine quite long to get oil everywhere!
I limited the use of the starter to 30 seconds, followed by 2 minutes cooling time. Took me 3 crank cycles to get everything filled up.

double check that your oil-to-cooler line is attached to the low part of the cooler. This will prevent air bubbles in the cooler when it fills up.

No pre-charging required as there is a small flow through the cooler all the time.
By the time the oil temp is high enough to need the cooler it will be full of oil.

I did not pre-fill the cooler and did not pre-fill any oil lines. Fuel lines were flushed up to the connection at that servo (less about pre-filling with gas and more about flushing out debris to avoid loading up the small filter in the servo).

Left out all of the plugs and cranked the engine (no more than 30 seconds at a time) until the oil pressure came up above 20 PSI. I don't think that I had to crank more than 30-60 seconds to get oil pressure. I overhauled my engine, so I had engine assembly grease in all key areas. This allows a good amount of well lubricated rotation, prior to oil flow. If your engine had been run on a stand, you should have positive pressure in well under 30 seconds, even with an empty cooler.

Larry

I did the same as the other posters, cranked with the plugs out until I got pressure.

As for the pressure senders, bleeding them is a waste of time IMO.

I prefilled the cooler (easy to do approx 3/4 quart) then cranked with ign off for oil pressure. Only took a few seconds.

Pre oil

I usually never fill the cooler in advance. With the spark plugs out you can turn the prop by hand for a minute or 2 and get oil flow and pressure. The oil pump is positive displacement and any rotation will move oil.

Don Broussard
RV9 Rebuild in Progress
57 Pacer

cajunwings said:

I usually never fill the cooler in advance. With the spark plugs out you can turn the prop by hand for a minute or 2 and get oil flow and pressure. The oil pump is positive displacement and any rotation will move oil.

Don Broussard
RV9 Rebuild in Progress
57 Pacer

Click to expand...

This or turn engine with starter spark plugs out to get oil pressure reading.

Thanks for all the great replies everyone. I will not worry about filling the cooler first. Makes sense that it will fill itself after running.

Just me

I stayed at a Holiday Inn Express last night so let me tell you.

I plan to pre fill mine for the simple reason that I would rather have oil pushing thru the system for first engine start, rather than air. I figure bearings like oil better than air when they are new and tight. YMMV