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Questions about converting to constant speed propeller

J

Jbon

Active Member
I'm getting ready to began a total overhaul of my RV6-A panel and electrical system. While I'm at it, I'm wanting to convert my fixed pitch prop to constant speed. My engine is an O-360-A1A, which is supposed to have a hollow crank. It has a governor pad on the back. For space, I've got about 8" from the pad base to the firewall, or about 11.5" if you measure into the firewall recess.

Are all -A1A engines hollow crank?

Is the Hartzel package from Van's the best bang for the buck?

My Sensenich has a Saber prop extension. Will I keep this, or does the Hartzel not require an extension?

Is there any chance I can keep/modify my spinner? Mine is aluminum and about 15" long.

I know that I'll need to remove the forward crankshaft plug, and add one to the rear, behind the oil tube. Having never done it, this is the part of the job that has my attention. Does anyone know someone who has done this, and who lives in the DFW area?
 
Jbon said:
Anyone. . . Anyone. . . Bueller?
Click to expand...

I have IA friend, he has never done it.

Where did you get your engine maybe they can be of assistance. I got mine from BPE and Allen knows how to do it. It will take a special punch to seat the aft plug without damaging the oil pipe.
 
If you build the airplane and bought kits from Vans, it is best deal for blended airfoil prop, one time purchase.

If not, I don't know where is best deal.
 
Here is what I know. For those that know better than me, please correct me if I'm off somewhere.

Are all -A1A engines hollow crank?
A: As far as I can find by designation yes, unless it was OH and solid crank installed and not logged (unlikely). Look at front of crank. If there is a plug installed (hammered in) then it is hollow.

Is the Hartzel package from Van's the best bang for the buck?
A: I do not currently have one but I think this is subjective and personal preference. There maybe space challenges with the longer prop gov's.

My Sensenich has a Saber prop extension. Will I keep this, or does the Hartzel not require an extension?
A: Not required with CS prop.

Is there any chance I can keep/modify my spinner? Mine is aluminum and about 15" long.
A: The cutout for the prop hub, front and backplates are different and will require modification/replacement.

Sheet C4 (ALL RV's)
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Full write by Brantel of doing this is here: http://www.vansairforce.com/community/showthread.php?t=101425
 
Last edited:
David-aviator said:
If you build the airplane and bought kits from Vans, it is best deal for blended airfoil prop, one time purchase.

If not, I don't know where is best deal.
Click to expand...
Probably a call to Van's is in order, but am I correct in my understanding that as long as the A/C's serial number has never had a Hartzel prop from Van's associated with it, I can get the deal. I don't have to be the builder?

John
 
pazmanyflyer said:
Here is what I know. For those that know better than me, please correct me if I'm off somewhere.

Are all -A1A engines hollow crank?
A: As far as I can find by designation yes, unless it was OH and solid crank installed and not logged (unlikely). Look at front of crank. If there is a plug installed (hammered in) then it is hollow.

Is the Hartzel package from Van's the best bang for the buck?
A: I do not currently have one but I think this is subjective and personal preference. There maybe space challenges with the longer prop gov's.

My Sensenich has a Saber prop extension. Will I keep this, or does the Hartzel not require an extension?
A: Not required with CS prop.

Is there any chance I can keep/modify my spinner? Mine is aluminum and about 15" long.
A: The cutout for the prop hub, front and backplates are different and will require modification/replacement.

Sheet C4 (ALL RV's)
tES4n11rEPEtNi3yQnkHUu25VJVMNGkwopr8qEkRqDyqJzeRCOTjWfFjZRjx4UEIgyjxKnqIWyrUo6XFqN9n2z5lvR5u4JLGoaenv-FL8l6VjAvmkdZzFGZ8cV8nhqQpWOZ0Fus_mjT6vY4nPFCUtbfDuP3Lbz4TTuttmKHieU5x1NPVoFQDg-LWZAM4Oeycn5W376-xEsdCOGyZK8a2yVDdSE3Ev2F_AchrzUyo43McSWeVD9h9WMfxpviZSwk3JQ9Md7TdVBdxPxahiyUCm4dDjHMzdD_cOwn_na1AcrDw65dsIkYGr7HU7xbZVqRYFtjuwEhax3SOAe8dgzEU_leWYOzlCgtvT4XB0OHmVmm7Vutw1FS92o5DH5hOgu8pYAnndjn-v8scHE4MXjSv93rPQ_zZ1-r9BPsBqyO20_z2Y0sH-iL6IMZ4P1rV6MgJRz2oyIB0SVqNwf4uDE9xUlbpDoVC6_bq5UEmA8ZSl1DARqxudsyvODB5MRdOZn6xZasrjpcxW9GrH3cyzQknNDp9BD2MCd_-CmmZuE9TIgqoY8TvCHr_4tmQNhNZ2k-c49c_SsbiH4cXiSLWFjhQ1kpfZ1u4pBmP-3w80cP3zJ5eFYZVHhjarbq-=w1453-h940-no


Full write by Brantel of doing this is here: http://www.vansairforce.com/community/showthread.php?t=101425
Click to expand...

So, if governor length is an issue, I assume I can go with a different manufacture, correct? Seems odd that space would be an issue. Aren't there lots of 6's flying with the Hartzel?

So, the prop extension is not required. I assume then that everything regarding the cowling will line up. I'm hoping the prop spinner will fit. Modifying, or replacing the bulkheads seems pretty doable.

Your link is just the information I was looking for. I seem to remember seeing this, but could not find it on the forum. THANKS!
 
You will need the prop governor adapter gear which you should find unsed somewhere, like this site, and hartzel governor and you will still have room to spare in front of firewall. You will also need bracket attachment to governor from Vans for cable attachment.
 
I would suspect your aluminum fixed pitch spinner might not work for the C/S. The openings for the blades are quite a bit different as the C/S blades rotate and you need enough room for their movement.

There is enough variance in the installation of the cowlings that you will just have to fix the C/S and see if there is interference or not or too big a gap between the cowling and the spinner.
 
Early RV-6s had 2 different cowlings for C/S vs. F/P. I don't remember which cowling John used. If your prop extension is 2.25" you shouldn't have a problem. If you present extension is 4", you may need a new cowling.
 
I did it

On my rv6 I changed from a fp sensenich to CS Hartzell.
I needed to add the firewall box from Van's for the governor and control cable to fit. Don't forget about adding the prop control.
Verify you have the oil inlet on the front of the crankcase.
Don't forget to change the plug in the crank for the CS set up.
I ended up using a high pressure oil hose instead of the stainless tube for the line from the governor to the front of the case. Much easier to get in there and worked for hundreds of hours with no problems.
I also used Van's CS spinner kit. It is significantly different from a fixed pitch set up and well worth the cost, In my opinion.
The previous posters all had helpful comments.
It's a great project and I was amazed at the increase in performance I got.
Good luck
 
Thanks everyone for the information. Mel, your comment about the cowl concerns me. I believe the spacer is thicker than 2.25". I'll have to measure it next time I'm at the hangar. If mine is 4", wouldn't that just give me a slightly larger gap between spinner an cowl
 
Jbon said:
Thanks everyone for the information. Mel, your comment about the cowl concerns me. I believe the spacer is thicker than 2.25". I'll have to measure it next time I'm at the hangar. If mine is 4", wouldn't that just give me a slightly larger gap between spinner an cowl
Click to expand...

No, because you will be removing your current extension. It is not used with the C/S prop. If you currently have the 4" extension, your cowling will be too long, and cannot be shortened (practically).
 
It should be a hollow crank. You can check by removing the prop and looking for the plug or checking your engine logs for a crank part number. Conversion is easy, remove outer plug and install inner plug. You will need a governor and adapter and should fit if you have the firewall recess installed. You will also need a governor line ran to a fitting on the front of the engine. There is a lycoming service bulletin about how to do this with part numbers. Service instruction 1435. Hartzell props have different length hubs to meet your needs. Prop extensions from Saber also work. What you need would depend on the cowl you're using and more importantly the weight and balance of the aircraft. It's a lot of weight way out front so figure that out first... Also you will need phase 1 flight testing and new airworthiness from FAA. Sound like a lot, but it's really pretty easy as long as the W&B are good.
 
Ulrich said:
Also you will need phase 1 flight testing and new airworthiness from FAA. Sound like a lot, but it's really pretty easy as long as the W&B are good.
Click to expand...

You may or may not need a new airworthiness inspection. Operating limitation wording changed around the time this aircraft was certificated.

Check the operating limitations issued to this aircraft. They are the controlling documents.
 
I'm pretty certain my spacer is 4". I was not aware that Hartzel made different hub lengths available. Seems like that would be the answer, certainly better than fashioning a new cowl. Can such a custom size be obtained through Van's?
 
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