WRK

My Feedback: (2)

Have a Saito 100 in U Can Do, it flies great but when I do hovering for more
than 30 to 45 seconds I lose engine power to the point that I have to stop
hovering or I won't have enough power to pull out anymore. I think the
engine is getting too warm, I have richened the high speed needle and will
open the cowl more although it is fairly open, just wondering if this is a
normal problem?

I am using exhaust pressure and a 15 X 4 prop. and 15% nitro fuel, the plane
will climb out of sight if the throttle is open I only lose power in hover after a short while
but I would like to be able to hover for a longer period of time.

Has anyone else run into this problem?

Thanks,

flierbk

thedak

My Feedback: (21)

Maybe a pump?

WRK

My Feedback: (2)

I can get it to run rich in hover so I don't think I need a pump, I was wondering if anyone else has had this problem, maybe the cooling on this model is a problem?

Barry Cazier

My Feedback: (17)

I have a UCD60 with that engine. I really like it. It doesn't overheat and it will hover nicely. I use 30% fuel, that will make the engine run cooler. Also, I'll bet you don't have enough airflow through your cowl. That is the problem with most. Attached is a picture of how I do mine. Open up the cowl and your problems will be over, I'll bet.
Thanks,
Barry

Barry Cazier

My Feedback: (17)

Another one from the front.
Thanks,
Barry

STG

My Feedback: (26)

Barry, why does 30% make the motor run cooler--richer setting?

fasterthanlife

My Feedback: (2)

One thing also to remember. While your 100 is hovering the UCD its most likely in the upper power range. So another advantage of overpowering more, besides more punch from a hover, is that it hovers at a lower engine speed alowwing th eengine to run cooler.

Barry Cazier

My Feedback: (17)

More oil content. Also there is just something about the high nitro, maybe you don't tax the engine as hard (more HP, Not using it). But I notice the engine runs cooler. Also throttle response is crisper which helps in hover. All in all I find the motors run a lot better on 30%. I use it in all my 4 strokes. Also, I actually lean the engine down to make them run properly. I get better mileage with 30% so even though it costs more per gallon, it's offset slightly by not useing as much fuel.
Thanks,
Barry

STG

My Feedback: (26)

Barry some of your results are opposite from what I expected.

Higher nitro--
1)have to open(richen) the needle valve to get it to tune.
2)burn more fuel with the needle valve open further.
3) Motor puts out more power & more heat

High oil content--
1) Less combustible content in the fuel raises compression and produces more heat.

I am not trying to tell you your results are wrong. I am just trying to learn something here.

rightflyer

You could try running it without a cowl to see if the problem disappears. It would at least tell you it was heat-related. Can't see your cowl, but the exit opening must be at leat 2x the size of the input. Most people overdo the intake opening. I knew a guy that just put his engine upright and put it thru the cowl-no heat problems there!

Barry Cazier

My Feedback: (17)

The only experience I've had with different nitro content was with my early Saito 100 and 82. With both of those engines I was able to lean engine about 1/8 turn in from where I was at with 15% Nitro. In both engines that was the case. It seemed to make engine "crisper" in all regards and of course gave considerable more power. And while I haven't used a temp gun or anything so sophisicated, the "touch test" tells me they run cooler. One thing for sure is they didn't overheat and lose power in hover. It corrected that. Also, the first thing I did when I experienced overheating was to open the cowls per above pictures. I did that when I was using 15%. It helped a lot. And things just got better with the 30%. Also, my run times increased with the 30% fuel. All my other engines, (more Saitos and some YS) I haven't ever ran the 15%. I started and still use the 30%. These certainly are not sientific results. Just seat of the pants stuff. But nevertheless. I can feel the difference and so far I don't see any negatives to 30%. Well, except cost.
Thanks,
Barry

gjeffers

i agree with barry, i have a 60 and 46 size and you have to open up the bottom of the cowl(i would take at LEAST half of the bottom out) and more wont hurt and open up the front as muck as possible. and i also agree w/Barry on the coolpower 30, i just cant afford it, thats half the reason i put my 100 in the 46 and it runs great on 15% now ive removed even more of the bottom since this pic getting ready for summer, it was 105 yesterday and i flew with no heating probs.

spratrbo

My Feedback: (28)

I have the Saito in a Fliton Extra 330 (AWESOME!!!) but before that the engine was in a Funtana40. I had constant issues with it in the Funtana. When I switched everything over to the Fliton I went the route of a Perry pump and a straight pipe. It was the best decision I ever made as the engine runs without a hicup from full tank to empty. Basicly any possibility of the engine leaning out as the tank runs out is eliminated.

I also agree with the cowl issue. I think the rule of thumb is the exit should be twice the size of the opening. And I don't think the opening of a UCD is big enough to start with.

Another thing I also suggest is changing props. I have never had great success with any of these ultra low pitch wide props and I have tried several on several different motor applications. I find that when you throttle out of a hover you just don't have enough punch. I am running a APC 15x6 and my Fliton weighs 6lbs 6oz and I am hovering less than half throttle and when I punch it it is ballistic! I really think the higher pitch will make a world of difference and if your plane weighs about the same the engine can definately handle the extra load.

Give it a shot.... I think between the cowl and the prop your problems will be solved and I am sold on Perry pumps. Running a straight pipe it sounds AWESOME! It's like a Harley in the air.

Good luck!

JP

PS I am running 30% heli

EXTRA ADDICT

My Feedback: (2)

If I am not mistaken the nitro will actually cool the engine if tuned properly. I have seen this in race cars that have been converted from gas to alcohol. My saito 82 would actually form condensation on the intake tube when I was running 30% nitro in it.

STG

My Feedback: (26)

I can be wrong here, but I think it is the alcohol in the fuel that helps with the cooling the most.




. spratrbo

What pump? Please post or send me pictures if you have them. Thanks