Raptor 50 (Hyper) Nitro vs Performance

[Aviation addict]

Guys,

I run a Raptor 50 with the OS Hyper on 12% Nitro (at about 1950). I very briefly tried 20% but didn't notice any difference although I must admit that I didn't know what I was doing with the needles.

What effect should you see if you go from 12% to 20% or 30% for that matter? Is the 1.9 hp using 30% Nitro? If so what output do you get with 12%?

[flyinfool]

As you go up in nitro the fuels typically have more oil.
This coupled with the fact that the nitro is carrying oxygen to help combustion means that you will need to richen the needles.
When I switched from 15% to 30% and dialed in the needles, the difference was like night and day. Maneuvers that would always bog the head before were now effortless.

There is a warning, Nitro (or just more power) is like crack, once you try it your hooked and can not ever give it up.

[Aviation addict]

There is a warning, Nitro (or just more power) is like crack, once you try it your hooked and can not ever give it up.


Hi Jeff. Thanks for the warning. I think I'll open the needles some and up the Nitro again. cheers!

[Mike C]

There is a warning, Nitro (or just more power) is like crack, once you try it your hooked and can not ever give it up.


Hi Jeff. Thanks for the warning. I think I'll open the needles some and up the Nitro again. cheers!

You may have been rich to start with ,,,Check temp after flying if it's not hot don't richen.

Tune her to run nice and warm ,,Not hot. Only tune if you need tuning pay attention to temp. :wink:

[iwasaseabee]

what would a good temp range be?

[Mike C]

Warm on back plate not hot. Mine doesn't runn too hot maybe 190-200 on the head ,
,but I touch it now,, havn't pulled out the temp gun in a long time.

[Aviation addict]

I usually just fly around some then land and get in there quick, putting my finger on the back plate. So far I've only ever leaned her until luke warm / ambient air temp. I don't have a temperature gun but does it sound like I need to lean the engine futher?

My Hyper 50 engines don't seem to last me that long - say 6 months changing the bearings after say 4 to 5 months. You can't damage an engine from running it rich - can you? Not sure what I'm doing wrong on that front. Maybe just flying too much. Maybe flying too hard on 12% fuel with a high headspeed (1950rpm) and a rich engine ????

After a day's flying I always run the engine dry at idle with the glow-start on just to ensure the Nitro doesn't kill the bearings. What do you think? :?

[flyinfool]

1950 is not a high headspeed, 2000 is normal.

No you can not damage the engine by running rich.

Setting the needle by temperature in the winter is a little dangerous, You can get to be to lean before the engine gets hot. That is where experience comes in, you have to set the needle by sound and performance.

When you say the engine is lasting 6 months, what is going bad?
And how many gallons of fuel are you burning in 6 months?

It is normal to have to replace bearings fairly often I wear out a rear bearing about every 10-15 gallons of fuel. The rest of the engine will last for years. the rear bearings seem to have a shorter life if the heli is stored in a humid location.

[Aviation addict]

Yep, what I find is that a brand new Hyper runs really smoothly and well for 4 months or so and then the bearings start to go. Once I've changed them for the first time they usually last about 2 months tops after that. Its almost as though the brass bushes on the con rod get a bit worn and hammer the bearings? Don't know.

This last engine ran great for about 4 months until there was a metallic type noise, which upon hearing I auto'd to the ground. The subsequent post mortum revealed that the piston ring and part of the piston had disintegrated, which is a new one for me. I've seen this happen to a friend who was running his engine very lean - but as mine is always cool I thought I was safe.

In line with the comment on the above reply - it is possible that due to the low ambient winter temperatures (3 degrees C lately) my engine may have been cool to touch - but still running lean. Not sure. It's hard to tell by smoke as I'm running Magnum which is pretty smokey even when lean.

New engine on order... going to be very very careful this time.

[stevehonn]

I had a problem with my governor and the Hyper 50 over-revved, popped then stopped. The post-mortem revealed a hol in the top of the piston, I couldn't get a piston from anyware at the time, the importers seem to have underestimated either the demand for spares or the fagility of the engine.

[flyinfool]

The hole in the top of the piston is almost always caused by running to lean.
I have a few of those in my collection. :roll: I some times (well most times) intentionally run way to lean for drag racing. New piston and ring after every day of racing.

What kind of bearings are you using to replace the factory bearings in your Hyper?
I use the Stainless Steel bearings from www.rc-bearings.com and they last a lot longer than the stock bearings.

In the winter I have seen pistons melted while the engine remained cool to the touch even at the head.

[hirobomike]

I agree with flyinfool, I have already replaced the rear bearing in my hyper after only maybe three gallons. It looked very rusty! Already the replacement is starting to feel rough. I think the damp atmosphere has a lot to do with it. I'm in Ireland, I always run the engine dry at the end of the day and only run on 15%. I've also smashed a ring and piston (saved the liner), but I do think that was due to running too lean - apparently the ring will break at the free end (at the anti-rotation pin) due to the slower heat dissipation there. Stainless bearings may be the answer for our climate!

[toast]

Just read this forum and thought I would add my 2 cents. Where I fly (Taranaki, New Zealand) we dont have the extremes of temp, but even so I havent killed and engine in over 5 years of flying. Not just helis, but planes and cars too. Here is my theory (may be wrong). I run Klots Super Techniplate in all my engines with Klots Nitro. The nitro contains Nitroguard thus protecting bearings etc. Fuel mix for the helis/planes is 15% nitro and 18% oil. We used to run 20% oil but after a couple of years running cars we started to experiment with oil content. In my OS 21 V-Spec I am running 25% nitro and 10% oil. It seems that as the oil content goes up the fuel gets thicker and doesnt "flow" as easily. It also means that you have less methanol in the fuel. Methanol does a large amount of the cooling so the less meth the hotter your engine will run. I figure if a car motor can run at 42000 rpm and 120deg c (250 F) and last a whole season with very little wear running 10% oil then a heli motor with a cooling fan revving half that and coming off load half the time should be able to handle a reduction in oil. We didnt go to 10% because the heli motors are twice the physical size and are ringed not ABC.
Has anyone else tried lowering oil content to reduce running temp?

P.S one of my 50 hypers is two years old on it original bearings. I have run 2 tanks a week through it fairly consistantly for that time. I have run both a GV-1 and Rev Max.