Engine discussion ?

[FlyKidChris]

Re: Engine discussion ?

JimmyBoyB50,
I've wondered about the TIO-541 or GTIO-541 in a sport racing application, too.
IIRC, the TIO-541 in the Beech Duke (or Baron 56TC) was rated at 380 hp and the geared version in the pressurized Navajo was rated at 425 hp. According to Wikipedia, the highest "stock" rating was 450 hp (geared, turbo-ed and intercooled). That seems like a good starting point, to me.
I wouldn't normally call that 450 hp version simple, though.
Chris

[IcePaq]

Re: Engine discussion ?

I'm amazed that modern engine management systems are not the standard on these planes.

We're getting near 1800hp out of a street driven car that blows pretty darn clean on the gas analyzer without a hint of detonation.

Even nitrous systems are going "closed loop".

[First time Juke]

Re: 2-STROKE.....still going strong ?

2-stroke engines:

I figured if you make really small plane like Cri Cri ( french classic twin...world smallest ) there seems to be still room for a 2-stroke ( and also electrics are gaining ground ).

I have so far found out that a Sachs Dolmar based small 2-strokes may be very efficient.

One maker claims his APT 6.4 cu in engine has only 0.3 OZ / min consumption @ 65 % power. Engine produces 13 hp...thus 8.4 hp would be 65%.

Some experts say this is simply impossible. Maker says his reed valve and 100:1 oil ( Amsoil ) makes the difference.

Is this plausible ? If not what is ?

Does nicasil in the cylinders ( or any other coating ) have a big effect ?

[GeoffS]

Re: Engine discussion ?

Is that Oz weight or Oz volume?

[First time Juke]

Re: Engine discussion ?

I have no idea...I have always figured one oz is 28 grams.

Air Power Technologies could advice more.

[Blue Foam]

Re: 2-STROKE.....still going strong ?

2-stroke engines:
I have so far found out that a Sachs Dolmar based small 2-strokes may be very efficient.

One maker claims his APT 6.4 cu in engine has only 0.3 OZ / min consumption @ 65 % power. Engine produces 13 hp...thus 8.4 hp would be 65%.
....
Does nicasil in the cylinders ( or any other coating ) have a big effect ?

Coatings do make a difference, not in this case. The numbers listed work out to .80 lb/HP/hr, about half way between a Continental at cruise (.38) and an unlimited on ADI (1.3). .80 is efficient for a small-bore 2-stroke, i.e. not very efficient. This number is not efficient for a long range aircraft, it might be quite suitable for a shorter duration UAV where engine weight is as significant as mission fuel weight.

[First time Juke]

Re: 2-STROKE.....still going strong ?

Coatings do make a difference, not in this case. The numbers listed work out to .80 lb/HP/hr, about half way between a Continental at cruise (.38) and an unlimited on ADI (1.3). .80 is efficient for a small-bore 2-stroke, i.e. not very efficient. This number is not efficient for a long range aircraft, it might be quite suitable for a shorter duration UAV where engine weight is as significant as mission fuel weight.

Your reasoning sounds solid. But I may remind you here the maker claims his engine consumes only 0.06 liter/HP/hr ie. 0.1 lb/hp/hr. But as you mention if he claims it is per one HP not the engine consumption in general..then you are correct !

If so then I do have found a better engine that burns only 0.36 l/hp/hr at 90% powersetting.

Here is the APT figure I mean; http://airpowertechnologies.net/UAV_64cuin.html

Well even if is per 1 hp then it isn't better or worse then others ..just normal I guess.

How come I did not notice it could be just one hp they meant ?

Maybe because others publish the total consumption like here for the DA-85; http://www.desertaircraft.com/engine...php?Page=DA-85

[IcePaq]

Re: Engine discussion ?

We're now getting near 2400hp from our 5.4 liter twin turbo ford GT which is a street driven car.

At lower boost levels, this car runs pump gas and is pretty sedate because it really doesn't have to run as radical of a cam with the 4 valve heads.

Still.......the frontal area of a merlin is actually smaller than this ford modular engine.

[First time Juke]

Re: Engine discussion ?

Install it mid fuse like this was in P-75; http://en.wikipedia.org/wiki/Allison_V-3420

[First time Juke]

Re: Engine discussion ?

ZDZ has 420 ccm 2 stroke;

http://www.troybuiltmodels.com/items/ZDZ420B4.html

Wonder if that could be ( if doubled ) to move this enclosed bird at 350 mph ?

Originally that is 35 hp but tweaked maybe 2 x 50 hp ? That does not sound much but in that bird it is more power to weight ratio than a stock Mustang P-51D has.

Could that be eligible to race in the sports class ?

Plane would be smaller than Cri Cri or BEDE 5B.

The nacelles would be bigger naturally as what drawn here.

[Race5]

Re: Engine discussion ?

ZDZ has 400 ccm 2 stroke;



Could that be eligible to race in the sports class ?

I hope not. That is way too small to be running in the wake of a 420 mph NXT.

[First time Juke]

Re: Engine discussion ?

I hope not. That is way too small to be running in the wake of a 420 mph NXT.

Hhahhahah !

Good one...since NXT cannot compete in unlimited class this Fenix cannot compete in Sports class.

What if I tweak it to go 430 mph and keep the NXT in wake turbulence ?

It would need two 25x38 props at 8000-8500 rpm to go beyond 500 mph.

I have not calculated if that makes the props go beyond speed of sound..possibly but then more blades and smaller dia ( like 24x38 ).

-----------

The prop would stay at 607 mph ( 970 km/h ) under the speed of sound at any rate.

[Race5]

Re: Engine discussion ?

Hhahhahah !



What if I tweak it to go 430 mph and keep the NXT in wake turbulence ?

You'd wake up. No dream ever ends the way you want it to.

[First time Juke]

Re: Engine discussion ?

You'd wake up. No dream ever ends the way you want it to.

This is true..none of my aviation dreams at least.



The ZDZ 420 version added below: