RCDENT

My Feedback: (2)

Weather was a bust this weekend, so no more test flying until next Saturday. It's apparent from the last few posts that I'm WAY under-proping the SF. I guess I was just "lost in the '80's" longing for the scream of short stroke Rossi's and YS's. Actually the SF I flew last weekend is a hand me down from my son-in-law and it had been happy in my Hangar 9 P-51.60 turning a 13x6 with a scale type muffler for several years. Tonight I'm ordering an assortment of 12 inch'ers to try on the new SF that is now in the P7. Will let everone know how it works out after I get some air time. Thanks for all the helpful input!

energyman

My Feedback: (2)

I ran the rear exhaust SF pumper in the late 80's with a DW 12x10 on a MK Joker. If memory serves me correctly, I was getting about 10,500 - 11,000 rpm. I second the opinion regarding the Mac's pre-tuned setup being too short for the SF. I currently have a Rossi long stroke 60 that has a Rossi long chamber pipe and uncut header that turns an APC 12x10 at 10,800 on Powermaster 5%. Mac lists a pipe for a long stroke 60. The part number is 1062. I have no experience with this pipe.

RCDENT

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Sorry for the duplicate post. Was having some computer issues and thought the first one was lost.

computermonkey

My Feedback: (90)

I came across this since we had been talking about MACS pre-tuned pipes for the OS 61 SF. I noticed that there is a coupler extension.
http://www.ebay.com/itm/390537869108...84.m1438.l2649

RCDENT

My Feedback: (2)

I called Macs today regarding that setup. I'm pretty sure it's the same one Tower Hobbies lists (in fact, it may be TH?). The gentleman on the phone was very helpful and seemed knowledgeable. He said that the SF combo is tuned for optimum results with the O.S. 61SF and a 12x8 prop WITHOUT the extra extension pictured. The extra extension is added for people who want to experiment with bigger props, etc. He indicated the Macs muffler I currently have on the plane should yield about the same power as the stock O.S. muffler (It sure looks a lot better, though!). I'm pretty sure I'll order the Macs pre-tuned pipesetup soon.

computermonkey

My Feedback: (90)

RCDENT, thanks for the information, that is interesting to know.

computermonkey

My Feedback: (90)

plane has been discontinued, what a bummer.

Jim Johns

Horizon Hobby's website shows that it's on backorder.

computermonkey

My Feedback: (90)

I called them, it's been discontinued according to the sales person.

Jim Johns

Well, that sux!!!

Jim

computermonkey

My Feedback: (90)

Ya I was going to order one, but now ended up with a Dirty Birdy.

Huang

My Feedback: (27)

Bummer!! It seems every time Horizon starts a deep discount on a plane, they are starting the process to discontinue it and clearing it out of inventory. They probably figured the first production run saturated most of the market, and a 2nd production run may sell much slower and not justifiable for their minimum production number and inventory costs to keep it.

On the good side, they *sometimes* introduce another model to fill the category. I know the P7 was a project Mike McConville put a lot of personal effort into making it happen. If it was a good seller, perhaps H9 can source another design to compete with the Dirty Birdy. But it might not happen, as if the P7 sold well they would not need to discount it and clear it out to begin with. But then, they wouldn't want to give all future sales out to Great Planes (DB) on a category they created, would they? One can only hope...

It's an awesome plane to fly, maybe the H9 P7 ARF will become a vintage collector's item on eBuy 20 years down the road.

dhal22

Damn, I was about to order another.

computermonkey

My Feedback: (90)

dhal22, I know exactly how you feel. I ended up ordering a DB instead. Should be here this week I hope.

stuntflyr

RCDENT

My Feedback: (2)

Guess I got to the party a bit late. Have put a few more flights on mine, and it gives every indication of being a nice plane. The tank position problem reared it's ugly head when I tried some outside loops, so I ordered a Perry pump and in the process of installing it now. I have seen 3 or 4 P7's flying around the local area, which seems pretty good for a single design. Hopefully H9 will do another run of them sometime in the future, or a different old pattern bird. Until then, we'll have to depend on smaller, limited production kit manufacturers and scratch building.Thanks for the memories H9!

Timthetoolman1

My Feedback: (6)

Yea, I picked one up today at the LHS for $225 It was my wife's idea, I've got plenty to play with but not one of these and since they are going away... The DB is still a few weeks out but this will give me something to play with.

Thinking I may put the OS .55 in it for now. Not sure what I want for it. It needs to go fast from what I've seen (or faster than the Kaos). I'm going to try the Macs 6720 muffler (SPA), if it's not enough I've got a Jett muffler. If that's not enough I'll have to put retracts and a NR or YS and tuned pipe and go look for CPA action!!!
My other choices are a Saito 91 and a Thunder Tiger Pro .61. Earlier tonight I got the 55 to 1500 RPMs higher than the TT and the AX is not even broken in yet but I've been told it won't hold it on an up line...hmmm, I'm testing it static with more RPM on a stock pipe so I'd think it would, any ideas?

The wing is done, the stabs are on and it's late so it will have to wait till tomorrow.

Great Planes makes a Stuka that they has been in and out of production for years. The quit for a year or two and bring it back. I wonder if H9 is doing the same?

Tim

Timthetoolman1

My Feedback: (6)

Or should I just go get the OS 65?

edp

My Feedback: (5)

I had this put in after my Webra Speed .61 ate itself.
My Dad added the extra servo for the in-flight mix. He does my ARF work while I'm painting two pattern birds in my build threads. (He is retired and it keeps him out of my Mom's hair) I'll be swinging an APC 11x10 after break-in. I bought the FIRE for a XLT build this winter.

Timthetoolman1

My Feedback: (6)

Awesome, I've been asking about those but I haven't received an answer yet, please let us know what you think.
I talked to one of the dealers and he said his customers are happy but I don't know how it compares to others.
It would be great if it gave the same power as the OS 65 or better. With a 55AX and a jett exhaust I'm going to need extra fuel so maybe the NRs will be better.

edp

My Feedback: (5)

Will do, I'm on vacation the first two weeks of July and I'm getting OUT of the basement.

Timthetoolman1

My Feedback: (6)

I talked to a good friend that flies expert (I'm just novice...on a good day...lol) and he said the OS 55 on the jet muffler with an 11x7 set to run rich is an excellent choice. He said he burns about 12 oz but they were having problems with fuel during the running 8 so they all switched to the Jett bubbleless tanks.

I know I need to practice on keeping it fast, slow on the down legs of the maneuvers (to keep from trashing the engine) and get it back on the pipe while it's still headed down so it will be available for the next up leg. Piece of cake [X(]

Jim Oliver

My Feedback: (1)

edp,
I don't mean to rain on your parade, but

Your NR is a great engine, but you will be disappointed with the rpm loss caused by that pretty muffler Also, the engine will be much happier with an 11x7 or 11x8 than the 11x10. Although the rear exhaust NR engines are "long stroke" (24mm), they are timed to run at higher revs. If you do run the 11x10, watch out for pre-ignition and/or detonation, rough running and high cyl. head temps. Bad juju if it happens

Zero nitro and low compression will help, but are more trouble than I would go to-just stay with the right prop and be happy!

Your side exhaust is 23.33 mm stroke, so is a short stroke engine, all the more reason for the 11x7 or 11x8 prop.

There will probably be those that disagree on this, and they are free to be wrong
Jim

edp

My Feedback: (5)

Hey Jim,
Thanks for the heads up. I haven't trimmed my TT spinner yet. NR doesn't give any prop recommendations anywhere. I have 11x7 to 11x10 APCs . The muffler is their version of a mini pipe. I hope Mac will bring out a Black Pipe to fit.

Jim Oliver

My Feedback: (1)

One of my pattern buddies has the same NR engine with that same muffler; a tuned system it ain't! Knocks rpm down about 800-900 from open face

Try your engine with out the muff in place then with the muff installed and compare revs.......