Pond Skipper

My Magnum .15 in retrospect 207g with prop and spinner.

The ASP and Magnum do not match in the mounting the ASP and AP do.

aspeed

I always wondered if the .15 liner would fit into the .12. The bore is .5mm more. The crank, maybe too. from the .12 to the others? The construction looks very similar inside.

Pond Skipper

Looking forward to trying the 09 and 12 will have to build a simple quickie type plane that can handle the weight and size of the engines. The bolt patterns are the same as I mentioned 10mm spread and the Magnum requires a 13mm spread. Alan I imagine the AP 15 matches the bolt pattern of the AP 15? The ASP seems to be made well I couldn't see any issues.

Pond Skipper

The new 16 MP 4x zoom cam came in besides mucho better res the rear screen is a nice feature. I down loaded the Android app for it and found it will digitally zoom further up to 48x! so look forward to finding a reasonable zoom in the field for close passes but still snags the distance shots. The cam came with a lot of different ways to mount and a nice water proof case if need be. For the first test day I will set at 16 MP and 60 fps and 6x zoom vs the old cam that did 5 MP at 30 fps no zoom.

Here are some pics old and new cam on the right. The camera I used doesn't
do the color on the two screens justice its actually very good and focused.

aspeed

I think you mean the .09 and the .15 AP are the same bolt pattern, and yes they are. Really the .15 is a no brainer, unless you are restricted to displacement for some reason. They are fairly well made for a $30 motor. I think just the design makes it cheap. Screw in backplate, no ports in the casting.... The .09 and .15 AP share many components, and I think maybe the .12 does too. I don't have one to take apart though.

Pond Skipper

Yes meant .09 an.15 = )
The 12 may have been a car / boat or heli engine at conception as that particular size tends to be hopped up for such things.
I have a handful of the Cox 6 x 6 as I suspect the sleeve porting may be more aggressive. If at 22k in the air 125 mph sure worth a shot.

I have held off on the AP 15 as I already have the Magnum and a handful of TD 15's

combatpigg

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I am glad to see that your camera seller finally came through. It will be interesting and educational to see how your camera "pans out"....[!]
I dismantled my cam to clean the forward lens. Sort of like a Cave Man doing brain surgery. I'm sure these things were originally assembled in Clean Rooms under magnification.
Not much to lose here by trying.
One thing has lead to another and my Jeep is still up on blocks. With 335,000 on the clock, I felt guilty and dropped the tank to swap out the fuel pump / gauge sender..basically to fix the fuel gauge. The weather has been erratic, so no big loss. The Jeep is an essential part of getting to the flying field, so it needs as much attention as it deserves.. !

Mr Cox

I think you're overestimating these engines a little...
The rated rpm values doesn't really mean much, over than possibly giving you an over-revving safety limit. It certainly doesn't mean that it will do 19k on the recommended 7x4 prop!

I typically get about 16000-16500rpm on the APC 7x4 prop, stock muffler and 10% nitro. They tend to vary a little from engine to engine, my best one has has a machining error in the exhaust (plus I've put a extra shim under the liner) which gives it a higher timing, and it will do about 17200rpm on the same prop. If you skip the muffler and shim the liner further (need to lower the head too then) you can probably improve the high-end a bit more.

Pond Skipper

A 6.5 x 3.5 could as most of us use more nitro in the US, how much nitro did you use to get 16-16.5k static?
- perhaps up to18.5k unloaded.


Here is an example with Chucks ASP .12 - My posted observations a while back:

My readings - 22.5K in the hand 26.8k best in the air 4P / 101.52 mph Max Theoretical
most 25.6k ish 97 mph. watched it a few times was in a rush off to work looking good CP!

https://www.youtube.com/watch?v=Uh5Inl6hzYE Chucks info:
Scratch built GLH..125% of original ACE RC GLH...240 sq inch wing instead of 200
Engine is $30 ASP .12 from HobbyPartz
6 x 4 Master Airscrew prop cut to 5.75 x 4
Down wind speeds over 110 mph, up wind about 90
Model weighs 18.5 ozs with 2 HS81 servos, Electron RX, 400 mah battery and 2 oz tank.

Mr Cox

Yes, but I think CP also used a larger CL venturi, no muffler, a shimmed liner etc. for that one? Plus the down-cut prop...

You can also look at it in terms of power:
5.75x4 @ 22500rpm : 190W
7x4 @ 17000rpm : 190W

So to get 19000rpm on a 7x4 prop you'll need a .15 engine. The ASP .15XLS will do around 20krpm as a comparison, and the weight penalty is only around 1oz.

Pond Skipper

I do have a 15 traditional in design that is 208 g in retrospect also have throttled TD's at 150.1 g
Below these are 8.4 g difference in weight. AP .09 / ASP .12
I'm not sure what mods Chuck has done perhaps he will chime in between working on his Jeep

combatpigg

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https://youtu.be/oaeeOR0G1Vc?list=UUvajm0pYeG7PvspskjQLq9A Not much to see with a stationary camera, but you can hear that the 5 x 5 prop was pretty close to ideal for the ASP .12

This was a stock engine that a friend owned, so the only grinding I was brave enough to do was to lighten the piston. The liner was raised by placing a shim beneath it. I removed the head shims to restore the original compression. The crank / bearing fit was very relaxed..it felt as perfect as perfect can get. Same goes for the P/L fit, very good.
IIRC, I made a C/L venturi for it and ran it on a latex bladder. The venturi would have matched the size of the crankshaft tunnel.
The 5 x 5 E prop is so flimsy and gave weak hand launches, but so far so good. The 6 x 4 MAS thin blade prop was the best all around choice, but of course not as fast. Bear in mind, none of this info is worth 2 cents unless you build a plane that is small enough and clean enough to take advantage of these tiny props.

Pond Skipper

I might be able to get away with 25% nitro APC 6.5 x 5 race prop if at 21k in the air 100 mph.
The blade gets very narrow quick.

Pond Skipper

Thank you CP!! Yes thinking a simple Quickie type 180 Sq.
In wing most likely another Skorch type able to handle this engine weight class.

combatpigg

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It's pretty hard to beat that simple layout.
I ought to try a ASP.12 powered Quickee with a 1/4" slab wing, too.

Mr Cox

Sounds like you have some bench running fun to do.

aspeed

Going over some old notes here, you are right on the money with the 7-4 @ 17000 rpm. My AP .09 was at 16,900. no muffler and 10%. I did scare it up to 18,200 with the same setup and a turbo plug head. Still not 19,000 though, but it wouldn't take much more to reach it, maybe just nitro. I think the ASP blue head may do better than 20,000. I was sure I had something on the 7-4 but couldn't find it. I think the ASP .12 might be happy with the turbo plug head just as something to try. I don't have one, and am not sure I need any more little ones, so I likely won't be doing it.

Pond Skipper

Thats good news ty Alan unloaded your over 20k not bad for 10% nitro.

Found this on the net;

Uploaded on Jan 24, 2010
1/2A Sized RC Delta with ASP .12 running a 6x4 prop to almost 27K RPM. Launch was a bit on the safe side (rich), but it still boogies! Second pass in video was dopplered at 105.8 MPH and in flight RPM calculated to over 26,500.
https://www.youtube.com/watch?v=Dh_7okxV6kI

combatpigg

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Small World..!
That's the guy who loaned me the engine.
He used to sign on here often.

Pond Skipper

Yes great he made an effort to find out his engine data with only a few of you all who have posted vid and reported rpms big plus to help sort out whats possible with props and the amount of nitro. The manual as you know Chuck is all in china lingo but the chart showing stock prop / rpm / weights for all of their engines is big plus.

Do you know if he did any mods on his engine?

combatpigg

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I don't know if he did any mods...[but he is a machinist]. He wanted me to continue raising the liner, but that would have made it necessary to make a custom head. These are things he could easily do.

aspeed

If I am shimming the sleeve any amount, I just face a bit off the top of the liner to gain back the compression. It can be a fairly small amount, because normally it is for a pipe, and a bit lower compression is good. The lip has to still have a bit of meat left though for strength. Here is a pic that is handy from the AP .09 which I think is similar. In the case of these AP and ASPs, A new turbo head wouold be in order though. The blue head ASP really responded well and even the AP ones I did was worthwhile. I don't think much thought was put into the heads at the factory. I made turbo plug heads for most of my little motors and the LA and Norvel .15 hardly had any gains, while the ASP and CS stuff really were a different motor after the head. I think the LA and Norvel paid the engineers a bit more to get better results. CP, "Small World" Maybe we are the only four people in the world that bought these motors. No one else seems to have noticed them. Too bad.

Pond Skipper

Alan that is some extreme porting!

I look forward to using the engine for sure it has made my short list for "to do" projects. I may have to add some carbon to the wing if 1/4" sheet wing perhaps 2 thin strips on the top and bottom across the CG across 3/4th the span of the wing. I think 180 sq. in wing would glide in reasonably well.

aspeed

I would just add a hardwood, or bass spar in the wing. Easier to blend in and has the same effect. Either way would be good though. The ports are not really extreme. There are no ports in the casting, so that is the whole port. The .15 is very similar, but the piston is much larger, so the ports are cut all the way through the sleeve, as the .12 is, I think.

combatpigg

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That is some very good looking porting...!
I've been afraid to "face off" the top of the liner and break through the plating...but it is something I'll try now.