palera

>>

I just read an article in one of the British magazines where the author had
had a lot of trouble finding the correct nut to replace his lost propnut. The gist of the
article (and this is from a Brit who has a LOT more exposure to Metric stuff than we do)
was that it is a rare and bizarre metric size, and you'll probably have to order one directly
from T.T. to get one. The British importer/distributor didn't even have one!

His feeling was "Why, why, why?"

So guard that propnut with yer life. BTW, I just bought a new TT .18 and am going
out to the shop to start the running-in process.

- Patrick

skaliwag

My Feedback: (1)

Read post #3... Likes the APC 9.5. Does 800 more than a PAW 19 on that one....

buzzard bait

Sounds like a good engine, but now I have an ASP .21 that I'm really happy with. It weighs 8.1 ozs. with muffler. Throttling, starting and power are terrific. 14,900 on Bolly 8.5 x4, and 13,800 on an MA 9x4. It's had only a brief break-in at this point. Even the stronger 15s weigh about 7 1/2 oz. For an engine around this weight, it definitely gets my vote.

Jim

buzzard bait

I know this is an old thread, but in case anyone cares anymore, the prop shaft thread is 7/32-32, of all things. Yes, you do wonder, why?

As if I needed another engine. But when one turns up on ebay for less than 1/2 price and no one else is bidding, what's a small engine guy to do? So I've got one now, at a price I just couldn't resist. Does make me wonder if they are selling any...makes me think there's no demand. I'm sure it's not nearly as powerful as my ASP .21, but I certainly have a use for a quiet, friendly engine than can swing a 9x4 prop.

It looks bigger than I expected. Even though it's a bit shorter than my Enya 19s, the cylinder fins give it a relatively big look.

Jim

Mr Cox

How much is the total weight?

I'm still interested to hear how it compares to a Veco 19 engine, a reference from the early 80-ties that still runs well;
Veco 19 BB with Perry carb, 7.7 oz in total with stock muffler, spins a Robbe 9x4 at 12500rpm on 10% Nitro (and 20% all castor) and idles down to about 2500rpm.

buzzard bait

About 7 1/2 oz. Muffler and needle are sealed in plastic and I don't want to open those yet. Put everything on the scale, it's not quite 7.6; take away the extra plastic...probably about 7 1/2.

So for weight, they are almost identical. The biggest difference in use would probably be noise. My recollection is the Veco has quite a small, simple muffler. Almost certain it has no baffles. I think they are pretty noisy, but I'm not sure. The TT should be relatively quiet.

Of course, the TT can be run on the low castor fuel that is the norm now. If you keep castor fuel on hand, as I do, then it's not an issue, and the Veco will probably last longer. The Perry is presumably a better carb, but I've had awfully good results from simple air bleed carbs in engines this size.

Plus the Veco looks very classy. The TT looks fine too, but it's not an old classic.

I don't know how a Robbe prop would compare in load to the props tested above...there can be very big differences.

Jim

dennis

My Feedback: (90)

The only thing that concerns me about this engine and it's bigger brother the 28 is the carb being an integral unit to the case. Given the predisposition of many new comers to plow into the ground nose first, that is a new crankcase in many instances. Hope the parts are cheap. Secondly is that it would probably make a great c/l engine but you can't swap out the carb for a venturi and needle valve. And speaking of throat diameter the 18/28 and even the 07 have the smallest venturi sizes for their displacement that I've ever seen. It's almost like they wanted to one up the OS LA series of engines in restricting the power output of their engines.
Dennis

buzzard bait

OK, you got me to pull it out of the box again. You are mistaken. The hole in the carb barrel is at least as big as the one on the OS 25 FP. It is definitely bigger than the one on my Enya 19 V BB or my OS 15 FP. It falls squarely in the normal range of sizes for sport engines.

In 20 odd years of flying RC I have never broken off a carb in a crash. This keeps coming up, so maybe other people have really bad crashes compared to mine. I think it's more likely to happen with bigger engines and heavier planes. The GP-18 is good engine for maybe a 2 to 3 lb plane...not a lot of momentum. I am not bothered by the integral carb at all...one less part to keep sealed.

This is never going to be a racing engine or a combat engine. It's biggest problem is that hardly anyone makes planes for this size anymore....the HOB AT-6 and Mustang, the Dynaflite Butterfly, and maybe some electric ARFs you could convert. It would fit right in with the old .15 to .19 designs, but you have to build them from scratch now. Which is what I plan to do.

DeviousDave

Or, Loosely translated: "Our engines are monolithic. That makes them better. Oh, and yeah,.... When you crash and bust the carb off the engine is scrap and you have to buy another one."

NickLeo0430

Is it worth it?
​​​​​​Ok I'm new to this and I'm looking for a motor for a Ace RC Simple Ultimate with a 33in wing span.
the model is one from my grandfather who passed away in May.
The plans recommend a Thunder Tiger GP-15, but as the RC world has changed a lot since these plans were printed in 2004 it's hard to find.
I have come across a Thunder Tiger GP-18 and wondered if they are any good?
I can find an OS LA15 but I wanna stick to the thunder tiger if I can...
Any help would be greatly appreciated!

buzzard bait

I still haven't run mine, but I read a review that said it did 12,500 rpm on an APC 9x4, with the muffler on, so that's as good as the old Veco 19 without a muffler. Total weight is 7 1/2 oz with muffler. Not bad at all. Can't speak from experience, but if it were my plane I wouldn't hesitate to try it.

A small bipe like that will be most enjoyable if kept light. These days it's easy to keep the radio light, and with a light engine, it should be really nice.

Jim

NickLeo0430

Thank you Jim,
on the box it suggested the GP-15 so I figured the 18 would be a little more power without going to overboard to a .20
it says it will handle .10-.20 engines but this is my first bipe and it being one of my grandfathers planes, this build means a lot to me and I wanna do it right.
It just had me confused because I wasn't used to seeing the screw on cylinder head in an engine this size, thought the screw on heads were mostly control line/U-control airplanesIt was either the GP-18 or the OS 15

Pond Skipper

https://www.ebay.com/itm/13418630240...cAAOSwBLVi5duS

buzzard bait

A lot of people fly these with 25s; personally I think the .18 is a better choice.

Jim

NickLeo0430

I appreciate y'all alot. And thank you Pound Skipper For finding that GP-15 for me. I went ahead and bought it. I'm thinking about getting ntue GP-18 still for when I get more comfortable with this Simple Ultimate. But for now the GP-15 goes on it since it's the recommended motor and this build is special to me because it was my grandfathers kits.

Pond Skipper

Your most welcome, choice of prop per engine and plane type can yield great results.
APC 7x4 - 7x5 will give a good mix of thrust and speed. Per engine type displacement a
generous oil percentage with 15% nitro should idle well with a med. heat plug.
Post some pics as you go along and flight vid if possible.

hsukaria

I have the Thunder Tiger 18 on a ministick plane. I previously powdered the same plane with an OS 15LA with good performance. By far the biggest benefit of the GP18 and GP28 are their ability to mount directly to the firewall and eliminating the need for an engine mount. I did a weight comparison between the TT GP18 with an OS 15LA and it's engine mount. The GP18 is lighter than the OS15LA with an engine mount. That is impressive considering how lightweight the OS15LA. The TT GP18 can spin larger props than a typical 15 size engine. So in my case, I got a performance boost while reducing weight. So the key is finding a plane that can accommodate directly mounting the engine to the firewall.