I Did It....ordered an IVO CAP

Thanks very much, Dean. All that you have posted is very helpful to me inasmuch as I'm starting at zero knowledge on this topic.

I got on the Eggenfelnner page and noted some stories from pilots using his engines. Most are the 2.5 though. Their MAPs were all over the spectrum from around 20 to in the 40s on their various trips. I've been O.K.-ed to post there, so I may throw up the questions I have. I don't know if many will be able to relate, as the E-engines have the electronics. My engine has none. It's a mechanical-type FI system.
 
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How does it feel as far as climb goes... comparetively?

If I hold it to 5100, it feels about the same as the Prince.

Don Parham should have some advice on this. If you ran your engine direct drive, I imagine you would be in the 3700 rpm range.

What was your speed in the cruise setting? Or were you just barely maintaining altitude? I might be inclined to shoot for a little more ...like 4200?

I was indicating in the low-70s, about what I show at an easy cruise with the Prince or Warp.

What could you hold altitude at with the Warp & Prince?

With the Warp, I used to be able to hold at 4200. With the Prince, it was around 4500. The Prince was pitched more toward a climb prop than the way I had the Warp set up....about 13.5 degrees if I recall. Subjectively, I feel I was burning much more fuel with the Prince, but never really checked either. Another caveat......when I got the Prince, I switched from the RAF engine tach to VDOs. I kind of suspect that maybe the RAF tach was reading too low, but never really checked it out.

Please try to tell me if you climb better at 5700 or 5200.

Again subjectively, I didn't leave it at 5700 for very long and powered back to 5400. The climb felt considerably better, but that's really subjective not taking any other factors into account.

Tomorrow (Monday), I'll tweak the brush bracket and then leave the airport area to check some cruise settings.
 
Dean, you'll confuse poor Ken even more! You said:

"Normally you will find that manifold pressure goes up (actually it is down because the higher reading means a higher vacuum) at the higher RPM."

No, it's not! The manifold pressure gauge on an aircraft reads "up-is-up." A higher reading is higher pressure, even though it's still less than ambient atmospheric pressure. A higher reading means less vacuum. If you advance the throttle and the pressure rises from 12 to 25 inches, you have less vacuum, higher pressure.

Ken,

The bit about making sure you have the manifold pressure and tach "squared up," or wanting 2500 RPM if you're pulling 25 inches of manifold pressure, is a coincidental relationship unique to aircraft engines designed for low RPM operation. Both RPM and inches of mercury are arbitrary units not related to each other.

In an engine which makes its max power at 5000 RPM, use a 2-to-1 ratio to keep the relationship meaningful, 25 inches at 5000 RPM. Even then, it may not be important.
 
Here's a chart I found on NSI's website. I hope it can be seen. The solid green line shows engine torque for the 2.2. Max torque starts at 3400 and stays pretty much there until 5400 and way beyond with just a little dipping fluctuation.

Thanks for your info also, Paul. I'm starting to get the picture.

Here's a link to the graph that may be easier to see. Hold your cursor in the bottom right corner and click on the icon to get an enlargement with the numbers easily read.

http://www.nsiaero.com/nsiaero2/4.0/4.1/4.1.4/4.1.4.6/Enginedyno.jpg
 

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Ken, Do you have a fuel flow meter installed? It would seem to me, with a fuel flow meter, you would be able to find the best engine/pitch combination.
 
Don't have one Chuck. I'm still trying to find space to mount the MAP gauge. Couldn't the least fuel flow be in a lugging condition though.....like driving 15 m.p.h. in 4th gear of a car?
 
Well, Paul, I'm not sure about Ken being confused but it seems either you or I or both are!

I was speaking of the type of manifold pressure gauge that is typically used with auto engines where the reading indicates how much of a vacuum is being pulled as opposed to how close the MP is to an absolute vacuum like an aircraft MP gauge. I may have made the wrong assumption that since Ken is running a Suburu, that he would use a auto manifold pressure gauge from his local Pep Boys.

The aircraft MP gauge is an absolute pressure measurement device where the auto MP gauge is measuring how much vacuum is being pulled. So, you are right if Ken uses an aircraft MP gauge then when the reading goes up it means that the pressure is getting higher although it is still below atmospheric.

In my simple mind it is easier to visualize and understand manifold pressure using the auto manifold pressure gauge as the reference. And I bet it is a whole lot cheaper than a aircraft MP gauge!
 
HAPPY BIRTHDAY DEAN.

I didn't realize you were that old; you old codger!!!


Cheers :)
 
Why Dean, I apologize...I didn't know, either! Even if your advancing age is the source of your confusion, it was rude of me to question someone so much...uh, so much more experienced! :)

Joking aside, the auto vacuum gauge will work, although it may be tough to discuss readings with other pilots. The automotive vacuum/boost gauges I've seen were calibrated in PSI, while the aircraft ones were inches Hg. Except, of course, the ones that some automakers put in as decorations, which have no numbers at all, just red and green zones!
 
Harry, only the body is old and I don't have any control over that. I'm just happy to see it hung on for one more year! Thanks for the thought.
 
Paul, I've always been confused but one advantage of advancing age is that now there is an excuse that everyone accepts!

All of the auto vacuum gauges I've seen do measure in inches of mercury. The compound ones used with turbos are as you have described except the ones I'm familiar with still have a inches of mercury on the below zero side.

Whether there will be confusion or not depends on what pilots Ken discusses manifold pressure with. He needs to pick his pilot friends carefully!
 
I have a gauge from Chief Aircraft Parts. Take-off distance and climb rate seems much better if I leave it at full take-off pitch, but anything over 5400 is wasted as that's where it peaks. I took a flight to the ocean today with a passenger and it was very interesting. I don't have time right now to post it all, so I'll be back later this evening.
 
O.K., I'm back. Weather was nice this afternoon after heavy a.m. fog and David was over for the weekend. He's Demetra's son that lives in a care facility about 1 hour driving time north. He weighs 185, I weigh 200 and we had 3/4ths of a tank of fuel, about 15 gallons on board.....and of course my new IVO cockpit-controllable prop. I tweaked the brush mount before we left so that the holder is squared off and the brushes are sitting just a hair off the pickup rings.

We took off showing about 5500 rpm. I throttled back to 5,000 and was still seeing a pretty good climb-rate. The prop was in full climb-mode. After we got up to my usual 500 feet AGL, I left the throttle where it was and activated the switch to move toward cruise pitch. The rpm started dropping and I let go of the switch at 4200 rpm. We were levelled off with no pitch-trim changes and clipping along at 65 m.p.h. per the GPS. It was actually 75 m.p.h. airspeed, as we had about a 10 knot headwind. Coming back, the GPS was showing as high as 87 m.p.h., so actually about 77 m.p.h. with the tailwind.

Everything felt smooth as I changed pitch from one end to the other. I cruised at around 4500 solo with the Prince prop. I got down to 3700 the other day with the IVO. As IVO says, "It's like having a transmission on your plane." I'm really anxious to wring it out some more and see where I can cruise best solo and see what kind of speeds I'll get with it in full cruise pitch and a little more engine rpm. The fuel burn will be interesting to check also.
 
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Alright Ken , so do you feel that at the same rpm, it is climbing better than the Warp? Is it quieter?

Is that a 68" prop?

Would it be a pain to start with just the prop & add the motor system later, or would this be no worse than installing the whole system right away ?

I imagine that this one is a keeper, huh Ken?

If you were an honest salesman , how would you talk me into buying one? I know you are honest for real, but give me a good reason for calling IVO.
 
Alright Ken , so do you feel that at the same rpm, it is climbing better than the Warp? Is it quieter?

That's hard to say, Chris, because you can depitch the Warp where you'll climb like crazy but only get 35 m.p.h. on the top end. I had 13.5 degrees on my Warp and the Prince and IVO outclimbed it at that particular setting. I don't notice any excess noise. Sounds the same as the Prince, to me.

Is that a 68" prop?

Yes.

Would it be a pain to start with just the prop & add the motor system later, or would this be no worse than installing the whole system right away ?

I have no idea.

I imagine that this one is a keeper, huh Ken?

As long as it holds up as to reliability, yes. Time will tell.

If you were an honest salesman , how would you talk me into buying one? I know you are honest for real, but give me a good reason for calling IVO.

I'd take you for a ride. I can't really talk anyone into buying one because I don't have enough time on it. Once I have 50 hours or so, I think I'll have a pretty good handle on it. From my research, the only problems I've seen were a delaminating of the blades from an outside vendor. That was very early on and they took care of it right away. If it holds up, I think it's a great buy at under 2 grand delivered.
 
Ken, how much weight did the adjusting mechanism add?

Oh yeah, did you get the Chief Aircraft parts manifold pressure gauge installed and if so what readings are you getting?
 
Nope. The gauge is still sitting in the box. Dean, retrofit kit for the medium prop that I have is 6 Lbs. That's to turn a ground-adjustable into the electric cockpit-adjustable version. I don't know what the blades weigh, but they're fairly light. So all the gear for the electric prop is only 6 pounds.

Attached are 5 pics showing the final installation. 1st one is fuzzy. I think the "focuser" was on my car in the background. Oh, by the way, as you can see, my AN bolts came in. Including shipping.....$150.00 for 6 of those long honkers. They're almost 8 inches long.

There's a customer of IVOs that makes spinners to cover the motor. I'd have to disassemble everything again, but it's really not that big a deal. I guess it would look nice with it covered up. I'm thinking about it.
 

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Well, if any additional incentive is needed, it is my understanding that a spinner helps prop efficiency with something called 'recovery'. I've read about it, don't understand it but I believe C. Beaty has commented on it.
 
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