is this a good sport engine? pros -cons"?

The Thunder Tiger Pro 61 is not the powerhouse that the Pro 46 is. It is timed conservatively. It will start easy, be easy to adjust, and give you many years of service. It's a little on the heavy side but not as much as a Super Tiger.


Enjoy,

Jim

Jim, I have this engine too and I was wondering if there was anything that can be done to get a little more power out of it without getting to radical. Maybe raising the exhaust port timing a little, lower the compression and uping the nitro??? Any ideas?
Danny Mercer, Rome,Ga

The Thunder Tiger 61 has never been known to be a screamer or anything like that. It's just a good ole everyday, reliable engine.

Engines with mild timing are generally not very responsive to Tuned pipes/mufflers nor Nitro as compared with a engine with high timing.

Other than taking the baffle out of the muffler and running 20% nitro, there isn't much you can do but just enjoy it as it is.

You could put the engine on a smaller, more streamlined shape, with a thin airfoil and with a smaller diameter, higher pitch prop, you might like it a little better but something like a Super Tiger 61 ABC would be more to your liking.

It would be cheaper to buy another engine with higher timing than it would be to mess around with the good engine you already have and ruin it.

A lot of people jump on here and recomend the MVVS. The Irvine 72 would be a pretty good all around engine. The OS 61 FX would be another good one. The Super Tiger 61 ringed or better yet, a 61 ABC or a 75 ringed would give you a good time.

You might pick up one of these higher timed engines at a good price used on here?

Jim, I just bought this engine on RCU about 3 weeks ago. I already own a TT Pro46 and just love it. I was hoping to get as good an engine as I already had. It's going on a Bridi Sun-Fli 5 for next years SPA contest if I can get it ready by then. I plan on using an 11x11 APC on Omaga 15% with a little more castor added(5oz per gal). I don't think the added weight of the TT.61 will hurt a short nosed plane either, that way I don't have to add any lead, just horsepower! I was just wondering if you knew anything I could do to get a few more RPM's. I don't want to ruin a good engine, I want to keep the engine relible too. Thanks.
Danny Mercer Rome,Ga.

There's no .60 on this planet that will rev with
an 11/11 prop. As an example....a Jett .90....
( a bad-ass motor) calls for an 11-8 prop. The
best you could do would probably be an 11-7 1/2
MAS. If the TT .61 is a "torquer"....( under 12 K
RPM's ) a 12-8 Zinger might work.

I don't mean to sound like a "smarty", or spoil
your plans....just tryin' to help. This O.S. .61 RF
is out-pullin' my old FSR on the Super Kaos, and
will not slow down goin' verticle. The MAS props
will out pull the APC's due to wider tips IMHO.
The RF is only turning 11,400 on the ground
( with the pipe ) and pulls like crazy with the 12-8
Zinger.

Just tryin' to help, like I said....try the 11-71/2
MAS, and if anything works better....lemme know.

Good luck...Dave.

tt engines marvelous but for the 61 .smmooooth but no kick. look at a rossi 53 much more power and great alround everything

Good luck finding the 53. I've heard that they have been discontinued.

Dave, Thanks for your input! I guess what I'm trying to do is get a little more power (not RPM) from this engine. At the SPA contest I talked to a few flyers and most told me to use a "Pattern" prop that was high pitched. So I bought an APC "Pattern" prop that is a 11x11. I fly a lot of sport planes and I have never seen a prop with that much pitch! That is what has me worried. I'm afraid that it woun't pull it, or it will over heat trying too! I still can't figure out why they told me to use this high of a pitch prop. What's the deal? Any info would be helpful! Any SPA flyers out there that know what's going on? Please help, as I don't want to fry this engine.
Danny Mercer Rome, Ga.

....let's face it, sometimes a dealer will push
something off on a guy, just to get rid of it.
Odd-ball stuff, or over stocks, ect.

But in the real world....you can get a dozen
prop recomendations from a dozen guys. It all
boils down to what actually works for your
particular plane. The engine size, RPM range,
the weight, size, and aerodynamics of the
plane....is what's gonna determine what prop
actually works best for your plane, at your
field.

Prop recommendations are good, for a starting
point however. If you have the instructions that
came with the motor, use those. Start out with
the choice of the smaller of the recommended
props. Allow the engine to rev freely, and not
overheat. The engine will break-in faster also.

Once it is broken in....nice clean oil on the plane,
not the black gook....you can prop it up a bit and
see what it will pull.

The 11-7 1/2 MAS is the best all around prop for
any .60. Later you might try the the 11-8. Some
will pull 'em, some won't. Then try a 12-6, or a
12-7 Zinger. Same thing....it might not like the
12-7.

I take back what I said about the 12-8 Zinger.
Your motor won't pull it, it may not even like the
12-7.

Dave.

Thanks for all your help, I think I will use the lower pitch because I don't want to fry the engine. You guys are great! Everytime I need help.....I know where to find it!!!
Danny Mercer
Rome, Ga.

I have a TT 61 on a Super Hots. At just under 6lbs it is a very fast plane with no verticle limitations. I have a Master Airscrew 12/6 on it. I am suprised to hear that the TT61 is not a hot engine. I guess 6lbs is not very heavy for a 61 but it sure does pull hard. I love this engine, you guys were right , no messing with this engine. Set it up and fly all day on it.

I'm not in the technical stuff of the exact meaning of mild timing, but from what I can see is that the engine has a very high exhaust port wich cuases it to be open some 170degrees.
Have run the engine with the standard muffler and it performed very poor. After fitting a tuned pipe it gained almost 2500 rpm. I have exerienced this engine to be very responsive to a tuned pipe.

There is a 60 that will turn an APC 11x11 prop. The YS 61 does so with ease. I used to fly this engine/prop combo about 7 years ago. The OS 61 RF Hanno can turn it also, but performes better on an APC 13x10.

I have a TT .61 GP and found it to have more power than my OS .61 FX ; in some situations.

I swapped the OS for a .61GP in a pattern plane running a 11x8 prop. The TT was using the OS muffler and the same prop, all that was swapped was the engine. The TT .61GP reved higher than the OS.

I had the TT in a 3D plane with a 12.25x3.75 prop and it made no power. Seems like the TT .61GP makes good power but not at high rpms. You need to find the right prop that will let it rev up but not too high.

....What' the diff. between the "Hanno" RF, and the
regular RF in my post #6 ?

I might have kept my hat out of the ring on this
one ....APC's are a horse of a different
color, for sure. Their thrust seems to come more
from the hub...to about 2/3 out towards the tips.
From that point on....the tips taper almost to a
point, as well as the pitch diminishing to almost
nothing at the tips.

When I talk about props, I generalize....and refer
to "regular" props. The engines see the the APC"s
as smaller props, and will allow more RPM, or allow
more pitch, that wouldn't work with a "regular" prop.

Example : see props below, both 12/8's....say you
were running an O.S., or a T.T. motor with the APC,
( .61's ) and life is good....it's pulling about 12,000
just like is should....plane flies just fine.
Now put the the 12-8 wood prop on.
PRESTO !!! You just turned it into a 10,000 RPM
DOG....

Dave.

Dave, The 11x11 that I bought is an APC prop. I think the fellow that told me to use that prop uses one on his plane and is trying to keep the noise down and trying to just use the torque of the engine and not the rpm. I still think it will over heat if pushed too hard! I'll just have to try to find the right combo for this engine and plane. I will give the 11x11 a try though, just to see what it does. He may know something I don't! (of corse that's not hard to do. :-) ).
Danny Mercer
Rome, Ga.

Flyboy Dave,

Here is a quick summary of the differences between the Hanno and the standard OS 61 RF:

1. The Hanno has an integral fuel pump that allows remote (e.g. on the CG) fuel tank location

2. The Hanno has sturdier bearings

3. I also believe the Hanno has different timing and compression to deliver more torque and raw horsepower than the standard 61 RF. The recommended props for the Hanno are the APC 13x10 and 12x10W.

4. The price for a new Hanno was 3 times the price of the standard RF, which is why I bought mine second hand!

Basically, the Hanno was designed to be a pattern engine, which it did very well. Up until the engine displacement restriction was removed, Hanno powered ships were still doing well against the YS 120 powered birds.

The Hanno had many advantages over the YS 61. It was very user friendly, where as the YS, with it's pressure regulator was quite cantankerous. It was the last, most powerful, and best 61 sized pattern engine.


Rob

....."He may know something I don't! (of corse that's
not hard to do). All I know is what work's
for me, and what I've seen in 30 yrs of this fun.

Awhile back, when I had an O.S. .60 FSR in this
Super Kaos, I stuck an 11-10 wood prop on it. Mine
you, the FSR is a screamer. It bogged the motor
down so bad....at first I wasn't even sure it was
gonna get off the ground ! I got it up, and turrned
and flew to the other end of the field, and landed it.

What a mistake that was ! The Kaos with the FSR
was fast ( trust me ) but it was sick with the 11-10
prop. That's why I said "no way" on the 11-11.
I personally wouldn't hang that much prop on a new
engine....but surely the next guy will tell you it will
work, just fine.

Dave.

Thanks for the heads-up on the Hanno.

I was gonna see if this FRS rear pump would
fit on my RF. Mounted up-right, and non-pumped
it does lean out pulling verticle, and in hard turns.

Dave.