DRBuilder

DRBuilder

Well Known Member
I have a Lycoming IO540 C4B5 260 HP engine which I have mounted a new Hartzell C/S Prop and a new Prop Governor, both purchased new from Van's. So far, the 1st few engine starts have been successful with one exception: I am not able to get the prop to cycle. There is an A&P shop here at my local airport and they loaned me a prop governor to install on my RV7 to see if it was my new prop governor that was not working properly. The borrowed prop governor cycled my prop perfectly. I then took my new prop governor to a well known prop shop in Burlington NC where they bench tested BOTH prop governors and found them both to be working properly. My A&P shop mounted MY NEW governor on the other IO540 (which happens to be a 300HP model... mine is a 260HP model) and it cycled the prop as well. This leaves us to believe there might be a leak in the crankshaft oil galley on my IO540, possibly the plug? Our reasoning is that the 260HP governor might produce less oil pressure required to cycle the prop allowing oil to leak back into the crankshaft and that the other governor produced more oil pressure and could keep the galley filled while the oil was leaking through the plug? Has anyone else experienced anything similar to this? I plan to remove the prop as soon as I can get back to work on my project to inspect the crankshaft plug but wanted to send out this post to explore all options before removing the prop.

Dennis Roberts RV7 N713DR Nearly ready for the 1st flight.

http://www.drrv7.com
 
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Long Shot!

Make sure that the "front" plug is not installed in the crankshaft. Sometimes the front plug is installed to prevent oil leakage during shipping. If so this will prevent oil from getting to the prop.
 
Isnt' there different models for wide deck 540's vs narrow deck ones.. which one do you have? Do you have the correct governor for your engine?
 
I am assuming I have the correct governor. I supplied Van's with the engine model number and they sent me the new prop and governor at the same time. I tried calling them this afternoon twice but "no one was available for builder assistance" the times I called. I simply couldn't be available during their short windows for builder's assistance. I was hoping they would monitor these posts and possibly offer some insight.

I am positive I removed the front plug in the crankshaft and the plug that came from the factory in the back of the prop hub. They are sitting on my workbench for reference.
 
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The rear plug was still in place, or at least "appeared" to be in place when I mounted the prop. What I can't figure out is why the other prop governor for the higher horsepower motor cycled my prop as it was supposed to. And to further complicate things, MY new governor (the one that will not cycle my prop) DOES cycle the prop on the higher HP motor. Go figure..... :( I'm completely puzzled. That's why I sent this post out to see if the higher HP governor also produced more oil pressure than the new governor for my 260 HP motor. That would make more sense *IF* there is a leak in the plug in the back of my crankshaft.
 
Oil pressure is oil pressure. It shouldnt matter what the HP of the engine is. If your governor tests right on the bench and the other governor works on the airplane something must be wrong with your set up. Are you sure your push pull cable isnt 180 out? (Should be pulling when your pushing) Wait im all confused here did you say a 540hp on an RV7 ;). You shouldnt have to pull the prop if the other governor is working something else is wrong.
Ryan
 
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