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Crank Shaft Plugs for CS Prop

David-aviator

Well Known Member
I need more adventure and am thinking about switching from the fine Catto Prop to a constant speed prop for the added take off performance.

Obviously the front crankshaft plug would be removed so oil can flow into the prop blade control unit. There is an aft plug inside the crank shaft which usually has a hole punched in it for a fixed pitch prop. My engine does not have that plug, it was never installed.

I've contacted Allen Barrett to see how difficult it would be to install it at this time. Is there anyone here how has done it?

The engine came with the prop oil plumbing with the drive gear but no control unit. I would have to buy it in addition to the prop.

I did a search on the Whirl Wind 74RV, some info turned up but nothing recent. If anyone has installed that prop on the RV-8 lately, how did it fit the cowl?

Thanks.
 
I swapped out a Sensenich for the 74RV on my RV8a last fall and used techniques similar to how others have already mentioned. Removing the plug was way more difficult than installing the constant speed plug. A simple wooden dowel with the appropriate slot and a whack or two and it's done.

I had Whirlwind custom size the spinner to flywheel gap. You can find the dimensions on their website. In my case, if I didn't have them customize it I would have had to cut back the front of the cowl. They were happy to do it.

Also, the rear spinner bulkhead was a different dimension than what I had before so I had to open up the cowling behind the spinner to give it room. Easy to do with a drum sander.

By the way, there are two spinner options. I wasn't sure which one to go with but I ended up going with the pointier rocket version. Glad I did.

I am very happy with the prop and spinner.
 
Thanks for quick reply...looks like it is not a big deal to get the crank shaft plugged properly.

Still debating which prop to get focused on. Vans Hartzel is the best deal money wise. The MT would work and so will the Whirl Wind.
 
I flew yesterday and carefully watched remaining distance markers on 26L at Spirit, the RV-8 was air borne in much less than 1000'.

That is not a new revelation, I knew it.

Sure, a CS prop turning up 2700 instead of 2200 with Catto would have been impressive but as friend commented on the thought of switching, what for? Performance on take off is not an issue with this airplane.

The down side of switching is the cost, work, and weight gain - most of it up front. The airplane weighed in at 1027 for certification and performs nicely, even on hot days.

As has been written in the annals of aviation, keep it light for best flying experience. :)

I've decided to leave it alone and read a good book instead of stewing over a prop upgrade. If were building new I'd probably go with the 74RV.
 
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