Which engine and muffler? Raptor G4

[LaurenceGough]

Hi guys,

Looking at the Raptor G4, it's a very light nitro 700 so I am not sure if a bigger block engine is necessary.

I'm not bad with electrics but nitro I just know the basics with and don't keep up to date with the latest and greatest.


I've flown Pete's G4 (thanks!) and I think he was using a OS 91 HZ R 3D speed and an OS 90 powerboost pipe. The power seemed very good as good as my electric 600.


Looking online it seems like everyone is pushing the bigger YS 120 and OS 105 engines. I've seen some insane flying with the YS 120 and to be frank I am not interested in running insane power but the weight of the engine is really low. I've heard the YS 120 vibrates more (not good with V-Bar)?

I am not sure what Pete was running with his G4 but I think I'd fancy larger 710mm main blades over 690's. I'm sure this will have a big effect on engine choice.

Is there much difference in flight times between the engines?

So my engine choices:


OS 91 HZ R 3D speed
YS 91 SRS 3D
OS 105 HZ R
YS 120

And as for pipes I really do not know... The 105 engine has the option of a 105 Powerboost pipe combo.

The MP7 looks like a good pipe at a good price, some people say it's better than the powerboost, seems higher pitched/louder to me but I am just going by online vids...

Hatori are fair bit extra in cost, and no doubt I'll ding it bad, are they worth the extra??

Thanks guys,

Laurence

[airwolf]

I have the YS120 in mine. The only pipe really for the YS is the Hatori, there are a couple of others but general consensus is that the YS should be mated with the Hatori. I think the vibes thing is misleading, all nitros vibrate and so far the YS doesn't seem any worse than anything else I have had. My main choice for the Bigger block engines over the 'smaller' 90s was the fact that I could run 15% nitro which is much cheaper and still have enough power to cope with my poor collective management!


TT X50, TT G4, TRex 500, TRex 250, Morley MXB

[trillian]

I have the YS91SR with Funtech pipe in the Avro, which is a good bit heavier airframe and it's still very capable for all the big aero moves. I just installed a TJ Pro and now it doesn't bog in repeated rolls / flips etc. If it was the weight of the G4 I can only guess it would be seriously nimble. (I am using SAB 710 mains at the moment and Rapicon 15%).

But my goal wasn't absolute max power but smoothness. The other pipe option was a Hatori but the price was about the same and I opted for the Funtech. For a punchier top end the Hatori is supposed to be better.

[shades]

I have the Redline 100H and Redline High Flow 3D pipe in mine...thats what the combo kit came with.

[debrooker]

poor collective management!

I wouldn't believe a word of that. lol.

[sacko]

http://www.rcheliaddict.co.uk/showpost.php?p=870702

Perfect timing?

[discoferret]

Nice one mate, your going to get one then? Turning to nitro, good move.

[waveydavey]

Laurence Gough wash your mouth out, LG Nitro, never....


Welcome to the wonderful world of longer flight times

[electricsceadu]

Laurence Gough wash your mouth out, LG Nitro, never....


Welcome to the wonderful world of longer flight times

no he'll just land with 2/3rds of the tank left

[trillian]

What I have always wondered is how much more fuel do you burn if you have a bigger engine but mostly run at lower throttle ? We all know that a 1.05 or 1.20 is going to burn more fuel at high throttle than a .90, but what about if you're flying most of the time at lower throttle not needing the full power except for the most demanding moves. So, you have maybe idle-1 where it never goes to full throttle and approximates the power of a .90, then have idle-2 for the full range (or actually the gov will do this automatically).

I would think if the power output is about the same, the fuel consumption should be fairly close as well (say between a 1.20 at 3/4 throttle vs a .90 at full throttle, just as a rough ballpark). The difference being that the bigger engine is having to push a heavier piston and crank assembly, so it makes sense some energy is lost but I have no idea how much.

[squeaky pete]

ive got a OS91 hzr in mine, its awesome, but lusting for a OS105 so that would be my choice

[Andy from Sandy]

What I have always wondered is how much more fuel do you burn if you have a bigger engine but mostly run at lower throttle?

Most of the smaller engines are designed to run on 20 to 30% nitro. The nitro doesn't contribute to the fuel but carries oxygen and as such requires the mixture to be set richer. The larger engines are deisgned to run on lower nitro so the mixture as a consequence can be set leaner and so you will use less fuel.

[trillian]

Most of the smaller engines are designed to run on 20 to 30% nitro. The nitro doesn't contribute to the fuel but carries oxygen and as such requires the mixture to be set richer. The larger engines are deisgned to run on lower nitro so the mixture as a consequence can be set leaner and so you will use less fuel.

Yeah, I'm talking about when using the same fuel. The question is more about engine efficiency for a given power output.

[moonmanflyer]

I hear the OS105 is the one to have, holds its tune alot better on the unregulated one.
The YS120 can be good or bad, heard mixed reports.
If you are going to spend the money, i would go for the newer bigger cc engines, wouldnt bother with the older types

[Andy from Sandy]

Yeah, I'm talking about when using the same fuel.

Part of the rational of going to the bigger engine is that you don't use the same fuel but one with less nitro. This is why the Japs designed them.