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  #481  
Old 08-06-2016, 12:14 AM
crabandy crabandy is offline
 
Join Date: Jan 2010
Location: Ottawa, Ks
Posts: 2,317
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I had to remove 1/2 inch from the front of my plug to utilize it as a 1 piece layup, I added the center plastic from my previous mold to the cut-off plug.



I re-faired it/epoxy coated it/sanded it/painted it, much easier and nicer the second time. I laid the fiberglass on the plug and trimmed it to shape.





I didnt get any pics of the intake boot layup, much like before 3 layers of rubber followed by fabric impregnated with rubber and a final layer of rubber. I did not add any reinforcement to the front ring this time, it is just rubber. I did add an extra layer of fabric about 1.5 inches wide On the back of the inlet ring to the boot, I wouldn't add the extra fabric again as it was hard to get it to lay right and was bumpy.

As part of my annual I also addressed the slop in my tailwheel and tailwheel spring. I added taper pins to my tailwheel yoke but found I still had a little bit of slop in the tail wheel spring to bulkhead mount as well. I used a B&S #2 taper pin reamer and a AN386-2-14 taper pin, the taper pin was way longer than needed but figured I could cut off the excess. I made this "jig" from scrap wood to hold the tail wheel fork perpendicular to the longitudinal axis of the airplane, I figured a large square of 3/4" plywood on a flat hangar floor with a 2x6 and spacers of plywood at 90* wood (pun intended) do the trick.



The jig worked well to hold the tail wheel yoke at the correct angle, but with the hole reamed to the correct depth for the taper pin left some hole slop to the left of the taper pin.



Reaming out the slop in the top of the hole ended up using the entire length of the An386-2-14 taper pin with lots of length protruding up. I tapered the inside diameter of some stock to make a large washer until I can order an AN-386-3 taper pin. It sure is messy and oily in the back!



The tail wheel is solid and straight now with no slop.

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Last edited by crabandy : 08-06-2016 at 12:18 AM.
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  #482  
Old 08-06-2016, 12:46 AM
crabandy crabandy is offline
 
Join Date: Jan 2010
Location: Ottawa, Ks
Posts: 2,317
Default Flying again!!

Another set of runups and de-cowlings made the first test flight a go! My goal was to incrementally increase speeds and record upper plenum pressures only, and not crash. I was astounded by my impossibly high upper plenum pressure readings but the airplane was performing normally with slightly cooler cylinder temps. I wasn't able to gather all the data I wanted due to lower clouds but still got in a .6 which was plenty for a first flight. After I realized I recorded pressures for the flight in mmHg they were much more believable converted to inches H2O. Looks like I picked up approximately 1.5 inches H2O across the speed ranges in the upper plenum and about 1 inch extra prop blast at 100 knts with the new cooling intakes.
I lost approximately 2 knots on the top only referencing my calibrated true airspeed. I was kinda expecting more speed loss actually, hopefully gain it back tweaking the exit next.
Oil temp seemed about 5-10 degrees hotter compared to the lower CHT's and topped out about 205 running full power, more investigation required.





Post flight inspection of the intake boots and cowling was good, I noticed 1 small crack on the front of the plenum/intake boot joint.



The intake boots are already showing some wrinkles....



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  #483  
Old 08-06-2016, 11:10 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by crabandy View Post
Looks like I picked up approximately 1.5 inches H2O across the speed ranges in the upper plenum and about 1 inch extra prop blast at 100 knts with the new cooling intakes.
That's about what I would expect.

Quote:
I lost approximately 2 knots on the top only referencing my calibrated true airspeed. I was kinda expecting more speed loss actually, hopefully gain it back tweaking the exit next.
Again, to be expected. Higher upper plenum pressure with the same exit size means higher mass flow. Cooling drag = mass x velocity loss, so higher mass flow means more drag. Squeeze down the exit area to return mass flow to the previous level. Upper plenum pressure will rise again in response to exit throttling. The drop across the engine will remain the same, so exit velocity will increase.

Quote:
Oil temp seemed about 5-10 degrees hotter compared to the lower CHT's and topped out about 205 running full power, more investigation required.
Unexpected. I don't know why.

Quote:
Post flight inspection of the intake boots and cowling was good, I noticed 1 small crack on the front of the plenum/intake boot joint.
The higher plenum pressure loads the front corners. 1.5" H2O doesn't seem like a lot, but how many square inches in your plenum lid?

Quote:
The intake boots are already showing some wrinkles....
Doesn't matter with a low Vi/Vo inlet. The boots are just sealing devices, not diffusers.
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  #484  
Old 08-06-2016, 06:25 PM
BillL BillL is offline
 
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Great to see you back in the air, Andy. That crack looks like a stress concentration at the end of the stiffener below?

It might not be faster, but it sure looks faster.

Look forward to full test results, when you get a chance, of course.
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  #485  
Old 08-07-2016, 04:33 PM
Reflex Reflex is offline
 
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Andy,
I was inside squeezing rivets when you went over. Nice motivator!! Could you fly over every time I'm in my shop?

Cheers!!

Fred
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  #486  
Old 08-08-2016, 06:00 PM
crabandy crabandy is offline
 
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Location: Ottawa, Ks
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Quote:
Originally Posted by BillL View Post
Great to see you back in the air, Andy. That crack looks like a stress concentration at the end of the stiffener below?

It might not be faster, but it sure looks faster.

Look forward to full test results, when you get a chance, of course.
Yes Bill, the crack does coincide to the aluminum clamping strip underneath. So far it hasn't grown, it's possible I just over tightened it.
I've spent enough time and fuel on pure test flights, I think I can gather the data I'm looking for on more purposeful flights......like on the way to Petit Jean for example.
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  #487  
Old 08-08-2016, 06:01 PM
crabandy crabandy is offline
 
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Quote:
Originally Posted by Reflex View Post
Andy,
I was inside squeezing rivets when you went over. Nice motivator!! Could you fly over every time I'm in my shop?

Cheers!!

Fred
Actually flying in an RV over your house is a way better motivator!
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  #488  
Old 08-08-2016, 06:58 PM
crabandy crabandy is offline
 
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More flights with G-Loading and aerobatics went well, so far the cowling/boots/plenum seem to be working well together. Perhaps I can leave the cowling on after a flight now.....

Not so fast, cowling and plenum back off for my first experience with a prop balance, you can see the sensors mounted on top of the engine. These are just my novice observations about the balance.



It took a wider piece of reflective tape for the sensor to see the reflective tape on the back of the prop, thinking the steeper blade angle of the Catto might have something to do with it. The airplane has alsways felt really smooth, my initial IPS (inches per second) was .15. The 255 was the degrees from the reflective tape in the direction of prop rotation marking the heavy spot, so move 180 degrees from that spot and add a large -4 area washer to the ring gear support. I googled that most aircraft have initial IPS in the .4-.8 range prior to balancing, I also had to google IPS...



2nd run showed the IPS lower and the degrees shifted slightly so we know we were adding weight to the right spot. If the degrees shift a lot the weight is too much or in the wrong spot. 4 runs total with another large washer and a small washer left an IPS of .01, time for one more run with a thin washer....or just leave well enough alone.

Thanks for the prop balance rdoerr01, she's smoother than ever!

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Last edited by crabandy : 08-08-2016 at 07:05 PM.
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  #489  
Old 08-09-2016, 04:06 PM
crabandy crabandy is offline
 
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Just under 2100 RPM is all I can get static, so that's what we went with.
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  #490  
Old 08-15-2016, 11:36 AM
crabandy crabandy is offline
 
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I decided to start sealing behind the spinner, pink foam cut out with a jig saw and epoxy/micro'ed onto the cowl. Im making the front hole behind the spinner smaller and adding a 90* flange with 1/2" clearance from the prop spacer. I'm thinking I can make the seal with 1/2 foam weatherstripping from the cowl flange to the prop spacer or some rubber baffle material from the cowl flange to the ring gear support.



True-ing up the front hole with a 7 inch circle routed from a 2x10.

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