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Old 06-19-2010 | 05:17 PM
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Kmot
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From: Northridge, CA
Default RE: Radial engine experiment: What do you think?

Thanks BW!

More revelations, and surprises, and knowledge gained this afternoon! [sm=thumbup.gif]

I just finished running the radial with a 22x10 MA wood prop (don't have a 22x8) and even though it is a bit large I figured it would be okay for a test run.

Once again I had trouble getting fuel up to the engine by hand propping so I hit it with the electric starter. It would not start! What the????

I fooled around a lot, cranking and cranking the engine, getting more and more perplexed, and finally pulled the fuel line and tried to force fuel through it and nothing would come out. I removed the fuel filter I have been using and fuel started to pour out the line! The fuel filter was blocking fuel from flowing. And the weird thing is the fuel filter element is spotless clean! I screwed the body back together sans the filter screen and reattached to the engine. Gave it a few turns and it lit off like normal.

I am now of the opinion that:

A) Fuel filters as well as fuelers and all other fuel fittings on the market are a waste of time, money, and cause numerous frustrations. This is not the first time I have had issues with an aftermarket fuel gizmo.

B) Part of the reason I was experiencing loss of power was due to the fuel filter restricting the amount of fuel the engine was demanding.

I ran the engine with the big prop, the more restrictive collector ring Version 2, with the drain line attached to the pipe in the exhaust outlet. It ran flawless! Idle speed due to the bigger prop was 1320, for as long as I wanted it to idle. Max RPM was 5100. Now an excuse: I drilled the prop slightly off angle. My drill press is a crappy, loose, sloppy, 24 year old drill press from China. I think the table is not 100% perpendicular to the drill column. I was able to notice, at idle, a very slight wobble at the tip of the spinner hub. Soooooooo, I think if the prop were perfectly drilled it would have gained some RPM. Not that it matters because I won't use a 22x10 normally anyway. Just sayin'...............

And about the drainage that comes out after the engine stops? I was ready this time, with a clear plastic bottle. As soon as the prop stopped turning I had the bottle under the exhaust outlet to catch whatever came out. Although on video it looked like it might have been clean, clear fuel drops, it is in fact used oil. When it is collected it is dark.

So I am happy! I have discovered and fixed a fuel delivery problem. My idea for having the crankcase drain feed into the exhaust outlet was not so far fetched after all, and the engine keeps running better and better. I think I have 2 gallons through it now. I believe I will see more rpm than ever before on the 18x10 prop since the fuel filter is out of the equation.
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