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Profi toy - 4/29/2008 3:52:49 AM   
Toad



Posts: 426
Joined: 12/3/2001
From: Hurricane, UT, USA
Status: offline 		I just recieved a new Profi .8 (.049) today from Jim Booker.
On first impression I must say I am impressed and not so impressed.
As you know I built a couple of my own engines last winter based on the "cool" idea of the venturi placed 90 degs from the standard position in front of the cyl. I was amazed to see the supplied venturi has a throat dia. of .195 as compared to the venturi I make for my modified Norvels, which I make to .190 the casting in real life is much better than in the pictures of this thing on the internet. I was also surprised a bit with the piston sleeve fit. There is absolutly no pinch at all at TDC. That is the part I am not impressed with, but I am not sure that we really need all that pinch anyway. I recieved the one that accepts the Nelson Plug, with the plug installed I was satisfied about that pinch issue in light of that the piston did not leak at all, I mean "0". I have not run it yet. another nice thing is that it is truely very light compared to my GZ's and my Cyclon. It is only very slightly heavier than my homemade engine that has no bearings in it. the bearings in this thing have a very velvet feel to them just like the Cyclon That Galbreath setup for me. One of these first weekends I plan on a heads up test between all my best 1/2a's on the same prop, fuel and plug. I will run them within the same hr/weather condition just for comparison. Rumour has it that this is the Cyclon/Fora Killer. I hope so. Cool little engine. Here is a picture on Jim's site of it. I am more impressed with the looks in real life.
http://www.flycontrolline.com/photogallery/MVC00029.JPG

< Message edited by Toad -- 4/29/2008 3:54:17 AM >

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speak 1/2a ?
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RE: Profi toy - 4/29/2008 6:12:08 AM   
combatpigg



Posts: 9527
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		Looks like they studied a Cyclon and decided to see where improvements could be made. That would seem to be an impossible task. My Fora had noticeable pinch before the first run, then after that it just did a good job of maintaining a compression seal. Jim lived nearby until a few years ago, I think he moved East to work for either Hobby Lobby or Horizon?
Anyway, hope you get many years worth of use out of it, I would break it in on a Blink if I were you.

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Led Zeppelin is NOT "old fogie" music.

(in reply to Toad)
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RE: Profi toy - 4/29/2008 12:23:53 PM   
GrahamC


 

Posts: 534
Joined: 9/19/2005
From: Ottawa, ON, CANADA
Status: offline 		Now that is cool! I have been wanting one of those too but other than just wanting one to mess about with I haven't been able to convice myself to spend the $$$.

Jim Booker had this to say (on the NASS forum):

quote:


Yes, I have them in my hands, ready to ship now. I got to run them today, it's crazy! On my normally 31K combat prop it hit 34100! On the full bladed 5x3 it ran 31,400. Tomorrow I'll test the Turbo plug head. Also have 1cc sample which Alex says is up another 3000 on the .8cc engines. By the way, Alex's test numbers on the .8cc were at 30K and a full 1000 higher than the Cyclon. When I ran it with my (supposed to be the same) prop I got the 31400 number! All runs were 15% nitro!


very cool indeed!

cheers, Graham

(in reply to combatpigg)
       Post #: 3

RE: Profi toy - 4/29/2008 11:46:43 PM   
DeviousDave


 

Posts: 407
Joined: 2/25/2007
From: , MI, USA
Status: offline 		The early Cyclons I have don't have much pinch either, but the third later one does. I think they did this to give people lots of power (FF motor, remember-short runs so pinch isn't so important), but later fitted them for better life.

Man, I really want one of these...

(in reply to GrahamC)
       Post #: 4

RE: Profi toy - 4/30/2008 12:06:16 AM   
Toad



Posts: 426
Joined: 12/3/2001
From: Hurricane, UT, USA
Status: offline 		I'm thinking that ABC construction would require more pinch to allow for correct fit when hot, not the case with AAC, both the piston and sleeve expanding the same, so no pinch required. Just my thinking on it.

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RE: Profi toy - 4/30/2008 12:25:53 AM   
peterburford


 

Posts: 187
Joined: 5/14/2004
From: Tallebudgera Valley, AUSTRALIA
Status: offline 		Much faster, of course, to have a good compression seal without the friction of too much taper and pinch.
Better, but more precision is needed, to construct to this accuracy rather than to run/wear to fit.
Peter

(in reply to Toad)
       Post #: 6

RE: Profi toy - 4/30/2008 12:52:22 AM   
combatpigg



Posts: 9527
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		Engines like these that can put up with the punishment year after year and provide so many thrills are a bargain. Anyone who has the eye sight, motor skills and desire should try this stuff while it is still around.

_____________________________

Led Zeppelin is NOT "old fogie" music.

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RE: Profi toy - 4/30/2008 1:50:39 AM   
Larry Driskill



Posts: 679
Joined: 6/2/2003
From: Lubbock, TX, USA
Status: offline 		Toad, How about I send you my Profi from the first batch ( 2 or 3 years ago) and you compare the two for us?


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Larry Driskill
Kitting It Together

(in reply to Toad)
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RE: Profi toy - 4/30/2008 2:04:04 AM   
Toad



Posts: 426
Joined: 12/3/2001
From: Hurricane, UT, USA
Status: offline 		I would probably forget to return it...accidently
Here is what I plan on doing
Nelson Plugs, 40% with all castor fuel, same actual propeller used on each, tach used will be TNC, I will run them within the same hr If I can. Engines to be compared will be my best VA, best modified AME .049, and .061. Cyclon .061, GZ .049 and .061, and the Profi .049
Not really fair to compare the .049's with the .061's other than it should be interesting. I cant do it this weekend. but the next.
THis will require me to change mounts and stuff, Im gonna be busy. I will try to get pictures of the tach numbers. If I have my own engine ready by then I will throw that in. (version 3 casing # 8) I'll post the info on my site, it needs a revamp anyway.

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speak 1/2a ?

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RE: Profi toy - 4/30/2008 3:08:24 AM   
peterburford


 

Posts: 187
Joined: 5/14/2004
From: Tallebudgera Valley, AUSTRALIA
Status: offline 		I like the venturi at the left.
The inlet port then helps the shaft counterbalance.
Peter

(in reply to Toad)
       Post #: 10

RE: Profi toy - 4/30/2008 8:23:38 PM   
lildiesel


 

Posts: 455
Joined: 11/18/2005
From: Cincinnati, OH, USA
Status: offline 		That venturi set up would lend itself to building a sweet little 1/2A combat plane.

quote:

ORIGINAL: peterburford
I like the venturi at the left.
The inlet port then helps the shaft counterbalance.
Peter



< Message edited by lildiesel -- 4/30/2008 8:26:52 PM >

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       Post #: 11

RE: Profi toy - 5/3/2008 2:22:02 PM   
Japanman


 

Posts: 978
Joined: 4/6/2003
From: Tsu, JAPAN
Status: offline 		i had a look at J.B`s site and i see the new 049 is 3K up with some combat props over the old one- you might be onto something there.

J.M

(in reply to lildiesel)
       Post #: 12

RE: Profi toy - 5/3/2008 10:45:21 PM   
Profi America


 

Posts: 8
Joined: 9/7/2007
From: Portland, OR, USA
Status: offline 		Guys,
Com'on, has no one run their engine yet? We got them out there and no body has time to run them! Less talk, let's get going! Michael Wilcox has some new 1/2A combat airplane samples coming for test with the new engine, can't wait at this end. Larry's LiteHawk will do the job anyway. Free flight testing at muncie next month.
Profi America

(in reply to Japanman)
       Post #: 13

RE: Profi toy - 5/3/2008 10:48:45 PM   
DeviousDave


 

Posts: 407
Joined: 2/25/2007
From: , MI, USA
Status: offline 		Any word on the .061's yet? I'm more of a pylon guy and could use all the torque I can get!

(in reply to Profi America)
       Post #: 14

RE: Profi toy - 5/4/2008 12:39:57 AM   
Profi America


 

Posts: 8
Joined: 9/7/2007
From: Portland, OR, USA
Status: offline 		The one sample .061 is now in Doug Galbreaths hands. He will be doing some testing of his own. Our own testing was extremely positive. It has considerably more tourqe than the .8cc so correct prop size is going to take more testing. I also have not had a chance to run hotter Turbo plugs in the engines but it seems that the availability of various heat ranges should be a benefit. Right now the Nelson plugs are about 500 better than the turbo plugs.

1cc will probably be at least 8 weeks away. Send a pm if you want to be on the list.

Let's hope for better weather tomorrow.

Profi America

(in reply to DeviousDave)