Who’s experimented with spinners?

16 posts in this topic

Posted (edited)

My new MK4 has the factory fiberglass spinner.  I left it off for the First flights so I could tweak my warp drive prop settings. I noticed it opens up the airway to the cheek radiators a bit. I’m thinking about ditching the big fiberglass spinner for the small skull cap warp spinner. Anyone know if a spinner gives any aerodynamic advantages or is it all cosmetic? The last pic is the smaller skull cap spinner

64F19573-4BCE-45CA-AA8F-36FDE24BFE00.jpeg

6E1C98DB-DE6A-4290-94BD-941404F8A794.jpeg

FA48D724-589C-4C3D-9510-A52BCD42C30A.jpeg

 

2BDB8D12-AA5B-48BD-99FC-1BC8D2A86446.jpeg

Edited by C5Engineer

Share this post


Link to post
Share on other sites

Posted

Not a lot of info on spinners - My Ercoupe had a skullcap spinner - Suberavid had one on his plane.  Guessing that they remove some of the turbulence from the prop inner portion?   EDMO  

Share this post


Link to post
Share on other sites

Posted

Not a lot of info on spinners - My Ercoupe had a skullcap spinner - Suberavid had one on his plane.  Guessing that they remove some of the turbulence from the prop inner portion?   EDMO  

I have tried to edit and add "drag" to this post twice, and it disappears each time I try - Reported it - Trying again now.  EDMO

Share this post


Link to post
Share on other sites

Posted

Not a lot of info on spinners - My Ercoupe had a skullcap spinner - Suberavid had one on his plane.  Guessing that they remove some of the turbulence from the prop inner portion?   EDMO  

I have tried to edit and add "drag" to this post twice, and it disappears each time I try - Reported it - Trying again now.  EDMO

Tried to change / edit "removes drag" to above and it don't work either - WTF!  EDMO

Share this post


Link to post
Share on other sites

Posted

imho you have to think if the plane was a glider would you prefer to have? i'd vote for big spinner

Share this post


Link to post
Share on other sites

Posted

I would think the biggest concern on the spinner is how much it affects your coolant temperatures - drag differences may be minimal no matter which one you use, but probably less than without spinner.  EDMO

Share this post


Link to post
Share on other sites

Posted

I would think the biggest concern on the spinner is how much it affects your coolant temperatures - drag differences may be minimal no matter which one you use, but probably less than without spinner.  EDMO

Joey,  Maybe it is ease of removal of spinner that concerns you for adjusting WD blades - skull cap is lots easier.  EDMO

Share this post


Link to post
Share on other sites

Posted

Joey,

My guess is the big vs little spinner makes no difference on a very draggy strutted aircraft like ours. Best way to tell is fly it without any spinner, and then with the big one and take a few careful identical performance points. The small spinner is clearly better than none, and it the difference between none and big is a slight diff, that proves the case.

Share this post


Link to post
Share on other sites

Posted

Craig Catto was giving a presentation at Oshkosh focusing on analytical details/results on the subtleties of propeller design. I asked the question about spinner vs no spinner vs skull cap for my Bearhawk (designed for slow end of spectrum with 0-320). He said there would be absolutely no measurable difference whatsoever between the options. 

Share this post


Link to post
Share on other sites

Posted (edited)

As an AME I was surprised once to find out that on a Cessna C-172 you were NOT allowed to fly without spinner. Indeed the spinner on this aircraft is designed and important for engine cooling...

On another application like a pusher Long-ez, you can have up to 50 Lbs thrust increase in flight (if my memory's good) by installing an aerodynamically shaped spinner.....It was explained to me that the low pressure area around the prop hub can be greatly increased using this long and pointed spinner....

Obviously a tractor aircraft benefits from a clean spinner installation (where as little space is left between cowl and spinner and no "step" present) aerodynamically.....don't know by how much though....

 

My 1/2 cent

spiner05.jpg

spinner-prop.jpg

Edited by flywise

Share this post


Link to post
Share on other sites

Posted

At least in streamlined tubes, a pointy front doesn't help as much as a pointy back.  Maybe that's why a front spinner doesn't help that much for improving performance/drag where the rear spinned did help.  JImChuk

1 person likes this

Share this post


Link to post
Share on other sites

Posted (edited)

In terms of drag the difference should not be noticeable but, as already mentionned, do keep an eye on your water temperature as the spinner (can) have a significant impact on the airflow to your radiators...   

Edited by FredStork
1 person likes this

Share this post


Link to post
Share on other sites

Posted

Thanks guys. I’m not a huge fan of the huge fiberglass spinner. It weighs almost 3 lbs and has 9 screws and backing plates that can all  exaggerate an out of balance condition. You have to undo the prop entirely from the hub to install the backing plate it’s a pia. The skull cap has one screw and you can still make adjustments with it on. Oh ya it cost $140 from warp!!!

Share this post


Link to post
Share on other sites

Posted (edited)

That looks suspiciously like a 4 stroke on that pallet mister.  

For my private check ride I had about a hundred year old guy from the FAA as my examiner.  This was in the days before the feds contracted that work out to "super CFI" types.  We spent almost 2 hours just on the oral exam.  One of his questions that sticks in my mind went something like: "You are on a long cross country and someone damages your spinner while you are taking lunch. Can you remove the spinner and continue on your way home and then repair it?"  

I said yes, I thought you could.  He then said WRONG and then showed me in the Piper Warrior operations manual mandatory equipment list that the spinner was listed.  It is required as a part of the cooling system. 

Now, of course we are experimental so that's just not going to happen the same way but as others have pointed out, the spinner CAN BE part of the cooling system to direct flow through the cylinders.  Try it both ways. 

By the way.  That check ride with him was almost all training.  He knew I could fly the airplane because he knew my instructor so we spent about an hour and a half doing commercial maneuvers, short approaches, cross wind landings, emergency descent technique through a hole in the overcast and other fun stuff.  He's gone West long ago but I'll always be grateful for the time I spent with him that day. 

Edited by Emory Bored

Share this post


Link to post
Share on other sites

Posted

Thanks guys. I’m not a huge fan of the huge fiberglass spinner. It weighs almost 3 lbs and has 9 screws and backing plates that can all  exaggerate an out of balance condition. You have to undo the prop entirely from the hub to install the backing plate it’s a pia. The skull cap has one screw and you can still make adjustments with it on. Oh ya it cost $140 from warp!!!

You don't need the one from Warp!  Measure around your bolt heads and order cheaper one from Spruce - I think it may be about 7" diameter?  EDMO 

Share this post


Link to post
Share on other sites

Posted

Thanks guys. I’m not a huge fan of the huge fiberglass spinner. It weighs almost 3 lbs and has 9 screws and backing plates that can all  exaggerate an out of balance condition. You have to undo the prop entirely from the hub to install the backing plate it’s a pia. The skull cap has one screw and you can still make adjustments with it on. Oh ya it cost $140 from warp!!!

You don't need the one from Warp!  Measure around your bolt heads and order cheaper one from Spruce - I think it may be about 7" diameter?  EDMO 

There it goes again - Try to edit and the whole thing disappears - ??? - I tried to add that years ago guys were pulling down on Cessna spinners to check the travel on the nose gear and were putting the spinners out of balance - Cessna made an AD with a big NO-NO!  EDMO

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now