iflynething

I have a Somethin' Extra and am having a big deal about what engine to get with the best benefits. Well, if you look at the .61 the stroke is .866 while the O.S. only has .776. But, the Irvine .53 has a .807 in stroke. I am getting an Irvine because of the power that they have................well the high torque that they have over almost all other engines. So, which on would be better for the Somethin' Extra? I would like to have the higher torque so I can swing bigger props so I can eventually hover. Thanks..........

jaka

Hello!
A something Extra is a rather small airplane so a 10cc (.61) engine is going to be a little heavy!
Better get a 7.5-8.5cc (.46-.53) engine. Most engines in this class are based on 6,5cc engine crankases so they weight nearly the same as 6,5cc engine. Take for instance the MVVS 8.0cc (.49) engine which weights just 6 gram more than the 6,5cc engine.
Regards!
Jan K
Sweden

JoeAirPort

My Feedback: (41)

jaka saved me a lot of typing. The .53 is much lighter than the .61. I would go for the lighter engine with almost as much power.

Joe

IronCross

Your probably not going to have the prop clearance with
the .61 to take advantage of the torque without ordering
a custom taller gear either. The SE will hoover with a .46
and with a .53 it really does anything you want.

iflynething

Thanks..........I was considering the .53 but just didn't want to over-do-it with too much power (is that really a problem having too much?!?!?!) But, I have heard that it will hover with a .46 but at what throttle setting......heard that you should be able to hover at at least 1/2-3/4 open throttle so you have the extra power to pull out of the hover...........HOPING TO TORQUE ROLL WITH THSI PLANE.....?????????!!!!!!!!!!!!??!??!??!??!....... But, what prop would you say for the maiden with a .53 or something similar...like an O.S. .51.......THANKS

IronCross

IMHO too much power is not bad, you have a throttle. The problems that
arise are weight and prop clearance. You add weight to the nose, and you
have to add weight to the tail. Starts adding up, the wing loading increases
and performance decreases. Most guys I know with the SE and a .53 are running
a 11X6 APC and seem to be happy with it.

iflynething

I will probably end up getting the Irvine .53........not too much power but enough and more than a .46 of any kind that I have found.......The guys at the LHS gave me......well my parents bought a 11x7 prop to start out with...but if that doesn't do fine and fit the plane AND the engine then I will make another trip to the HS to get another prop......oh yeah......forgot one thing.........I will probably get a tuned pipe later when I can come up with the $50-70 extra dollars..........I think that pipe should and will make a difference..........

IronCross

Sounds like a plan. You will have plenty of power for the SE. The
Irvine will swing a 11X7 fine, just give you a little more speed.

JoeAirPort

My Feedback: (41)

Really? Man that seems like too little prop. Do you mean 12-6? I thought I saw you post the 12-6 as the perfect prop in other threads. Well anyway, that's what I use (12-6) on my Magic Extra for 3D stuff and it works great.

Joe

IronCross

I did, however there is not sufficient ground clearance
on the SE for a 12 in prop without a custom landing gear
or some tall tires.

iflynething

Well, what would be the best "torque" prop for this plane...I am not wanting to fly it fast.....it isn't even made for flying fast but aerobatics..and I will be hovering (if I can) and don't need a speed prop????!!!?!!!!?!?!?!!!!!?!?!?!??!!

IronCross

Probably a 11x5 or 11x6.

jaka

Hello!
Well...if you use the .53 Irvine engine a 12x4 or a 12,25x3,75 APC would work for hovering manuvers...11x6 APC might also work but will give more forward speed.

Regards!
Jan K
Sweden

IronCross

Your right, however the ground clearance is not there
for a 12 inch prop. If you do not want speed that kind
of leaves you with the 11X5 or 6. Lots of guys in the club
use this combo and it seems to work well

Hobbsy

My Feedback: (102)

Speaking of the above mentioned throttle, the .53 throttle response is very linear and predictible, no flat spots or surprises. Talking about torque, I have always run a 12x6 three blade on my .53, turning about 10,700 rpm on 5% nitro. It is a Diesel now though.

ofremmi

Hi
I would say that a 11x5 and even the 12.25x3.75 is too small for the Irvine .53. Several here in my club has this engine in fun/3D planes and we all agree that the APC 13x4 is the best compromise. Plenty of pulling power with reasonably low noise. My Laser 3D is 2.6kg (5.7lb) empty and it's got plenty of power to accelerate out of hover with the .53.
Best luck.

IronCross

hobbsy
Now thats interesting. I have never tried a 3
bladed 12X6. Does it put out more torque then a
2 bladed one ?. I have always heard the 3 bladed
props were less efficient then the 2. Like I said though
I have never tried one myself.

IronCross

ofremmi
IMHO you are right, my favorite is the 12X6 APC.
However once again you need the ground clearance
for the 12 inch + props. A 11X5 or 11X6 will still give
plenty of torque for the SE, real quick throttle response
etc and still stay withing the operating parameters of the
engine.

Hobbsy

My Feedback: (102)

At the rpm I mentioned, I doubt the effeciency is an issue. I also doubt that the 12x6 three blade would be suitable for what you guys are doing, but it might be worth a try.

IronCross

Your right, it would be interesting to try.
Next Tower order I will pick one up. I think
the 3 bladers look better on a lot of planes
anyway.

iflynething

Well, sorry for bustin everyone's bubble, but I have ordered a O.S. .46FX....I don't think that this will be a good choice.........would perfer a .53 but the hobby man convinced me that the O.S would be more reliable....but......he said that a 12.3x5.75 or something like that wold let the plane how even with the .46FX.........Who says that I can't always sell the .46 and get the Irvine..?????????

AMB

You will be ok with the OS46 But as far as being told it is more reliable than the
irvine I don't buy the Irvine jetstream carbs are one of the best and as Hobbsy
stated very smooth response linear that is one of the principle reasons I have stuck with irvines all mine are now diesel ,they are both very high quality engines so it
comes down to personal choice.

JoeAirPort

My Feedback: (41)

The Irvine .53 is the perfect step up in power for planes with the 46FX. Same size and weight but more torque. Anyone who likes the 46FX do themselves a favor and try the Irvine .53. It's another experience altogether. Irvine quality might be a tad better at the very least IMO. Performance is way better for 3D on the same size plane.

Joe

iflynething

Well actually, just ordered the engine and it will be the NEW O.S. .46AX engine line.....this one has 1.65 horsepower and will have more when I get the tuned pipe or "header" for it........

SwampFlier-RCU

Sorry to see you Go from what Irvine I want to .. I got an OS
I still believe you get more worth out of yourmoney form the Irvien .53 proven workhorse than the OS 46 AX new design. It is not a bad choice OS engines are good but IMHO Irvines are better
good luck with your new Engine