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Using the special bypass cover plate in a C/S to FP conversion

Bob Axsom

Well Known Member
Deleted in the interest of safety - It is too complex an issue and the risk of misinterpretation is too great. Bob Axsom
 
Last edited:
Bob,

Good write up & pictures! I did this conversion before installing the engine - so it was quite straight forward. I got the engine from AeroSport Power set up for C/S operation. Things change & I installed an FP prop. Sue at AeroSport sent over the new governor cover and appropriate gasket. Things worked first time and I was ignorant of the gotchas that you found! I see no reason not to recommend this conversion for those that may want to install a C/S prop in the future.

Sorry to be smart after the event, but perhaps it is worthwhile getting the mod kit from a knowledgeable supplier?

Pete
 
Bob - how about part numbers for the plate, gasket and crankshaft plug. I am assuming you removed the complete governor drive assembly.
 
Lost 4.4 knots, that sucks Bob. What Rpm were you turning it at? As fast as the other boys?
 
I bought the crankshaft plug from Aircraft Spruce it is STD1211. Everything else was obtained from a friend of a friend through telephone description. It seems that this special cover is known to exist but its part number is not known to me personally. I have seen drawings of it and descriptions on the internet, in this forum in fact, but you will have to do a little research to come up with a source.

I did not remove the governor drive shaft, adapter or anything except the governor itself. In a few minutes I will be going back to the airport to reinstall the governor and C/S prop until the SARL racing season is completed three weeks from now and we have time to develop a better FP prop. We made a fast shot in the dark and lost 4.4 kts.

Bob Axsom

The cover is part number 72378 and is on page 2-5 of my PC 306-1 Lycoming parts manual, dated as a 1991 reprint

Nothing hidden about it...:)

http://www.aeroinstock.com/products/72378/5930/24690/product_detail/index.html
 
Hey Bob, The gasket I just took off my Vans IO360 did not have the slot cut out. I just figured that the recess in the cover flowed the oil out behind the gasket. Are you saying this does not always work that way?

Thanks for the note, I am sure it will be helpful for the Cs-Fp conversion.
 
does anyone have the cover part number for the cover when there is no drive unit?

69106 per the Part Catalog with a 69551 gasket.

Please check with an up-to-date catalog though, it also depends on the accessory housing you have. Three different ones are listed for the -A1A engine.
 
Deleted in the interest of safety - It is too complex an issue and the risk of misinterpretation is too great. Bob Axsom

After the positive comments, just curious what drove your decision to delete your post? I always enjoy your posts, BTW.

PS: (Never got to read your OP.)
 
After the positive comments, just curious what drove your decision to delete your post? I always enjoy your posts, BTW.

PS: (Never got to read your OP.)

+1 Bob, please re-post. There are several of us interested in your post. We will do our research and due diligence for proper install.

Thanks.
 
I'm Sorry

After I got the new prop last week I worked day and night to make the conversion in time to fly several hundred miles to get to the race site in southeast Texas. The recurring mysterious source oil leaks were a challenge working from a conceptual idea of how this was supposed to go together and function with no real details of function, performance or implementation and with incompatible parts. That I figured out the gasket problem was one of those miracle breakthroughs in my little world that allowed me to compete. I arrive at Jasper about an hour before launch.

I live in a world of one and I sometimes focus my limited attention on a problem and I don't realize at the time that many people have a broader perspective and can get into trouble if the right focus is not applied to the task. This thing has life threatening consequences if it is not done right and I thought I should share my findings. However, I realized that this is just too critical for casual consumption and it would eventually stimulate someone to try it that isn't as intense as you folks. I do not want to be responsible for someone making a frivolous attempt without formal instructions and having the ultimate failure. As I said my original intent was to share my findings and help others that are going through the same thing but I realized that it was arousing interest in the mod that didn't exist before and I don't want to do that - leave that for the experts.

Bob Axsom
 
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