West .50V1 bench run
 

[link=http://www.youtube.com/watch?v=QWhahZdRxfw]West .50V1 test run[/link]

Been tuning the header/Mac's pipe setup. Turns out I was flying too long before, no wonder I thought the Demon was slow. This is running nicely on the 8.0x9.25 flight prop now, so I'll cut back on pitch and bring ground rpm up to 20 - 20.5k and tune the system to that. Then fly it on the heavier pitch props. Time for an IMC on this one too..

MJD

RE: West .50V1 bench run
 

Sounds mean! You don't worry about it popping and chunking your finger while priming it with the glow driver on?

RE: West .50V1 bench run
 

No, not really. It wasn't wet with fuel at the time, there were no bumps, and I had some sort of a hold on the prop as I pulled it through compression as I recall. The fuel draw is modest like that, notice I had to pop the end of the pipe to get enough fuel in.

EDIT: nope. I watched - I was doing this by habit so I had to think about it. I hold the prop firmly as I turn it through compression, then the quick turning motion is the not-so-hazardous half of the cycle where I bring around to the compression stroke again and grip it to pull through.

It does sound pretty good on the open pipe. The Demon howls in the air with this one. This is a prelude to putting it back on the Demon in better tuned form and getting radar on it.

MJD

RE: West .50V1 bench run
 

How do you think those pylon racing props would do on it? The ones used in magnum nelson q40 engine recently?

RE: West .50V1 bench run
 

Not the right kind of prop. The West is a stormer in the 19-21k range, those props are intended to be spun faster than that. They use less pitch than I do on this, but spin it more than that ratio faster by a large margin.
MJD

RE: West .50V1 bench run
 

what happens, if it spins to fast? damage ?or does it just max out at max rpm?

I thought keeping the rpm up was good.

I've been looking unsuccesfully for those pylon race props here. Shops just seem to stock standard apc sizes.
If its not worth it, i want bother looking anymore

RE: West .50V1 bench run
 

The Webra .50 stands kind of tall, which makes me wonder if it is a long stroke..."under square" engine? I guess that is easy enough to go look up.........

RE: West .50V1 bench run
 

The Webra .50 is .900 bore X .780 stroke, so it's over square...

Just exactly what are the differences between the Weston and a stock Webra .50?

RE: West .50V1 bench run
 

That head is mostly air, it's kind of a helicopter-ish cooling head. If you trimmed it down on the lathe it would probably look normal.

mkI: revs are good, but if the porting and timing of the engine result in the volumetric efficiency going downhill past the point where the increasing rpm times the diminishing torque no longer results in a power gain - then you have exceeded the design potential of the motor as is. This engine's horsepower peak is apparently in the 21k area. If I ran it at 25k I expect the motor would hold up fine, but I also would expect to find that 25k/21k rpm increase times the (torque at 25k)/(torque at 21k) decrease would result in less power output. Unless I modified the motor to breath at those rpm. Power = speed.

The idea is to burn as much fuel/air mixture per second as you can, so revving higher does of course increase that potential courtesy of repetition, but if the engine can maintain some breathing efficiency. The design parameters that allow it to do so make it more and more of a special purpose engine as you climb in performance potential. The old rule of never getting something for nothing applies once more. The MB40 for example ingests and burns enormous amounts of fuel/air mixture at 30-33k or whereever it runs, but try to run it at what, 16k?, and see what happens. One day we'll have the universal .40. Oh wait, that's a hipo electric ([X(]).

MJD

RE: West .50V1 bench run
 

I don't have a Weston, but if someone with one gets some timing numbers, I'll get some numbers from my Webra .50 GT. Unless they have Webra do special runs of liners and possibly cranks just for them, these engines could be nothing more than "tweaked", with possibly the combustion chamber opened up, liner raised, crank port closing timing increased, bottom end fits checked, bearings upgraded, etc.
IIRC, I did check mine once and saw nothing really astounding...just a good quality engine.

RE: West .50V1 bench run
 

I have been told it is a higher timed version, kind of like a Webra Speed 50LX if you will.. makes perfect sense with the peak power range and misery when propped under the high teens.

It was too cold and miserable to continue today, I stuck it out far as I really felt like. But I will have another go tomorrow and see if i can't dial it right in. I was posting this mostly because I've encountered a couple of folks who have or plan to have these engines, but you don't get to see them run everyday at the club fields so I thought this might be interesting. And I might also fit the Genesis pipe and compare; the main reason I am not using the Genesis pipe on it is at the moment is that it weighs more than twice what the open pipe does, I like the bad attitude sound it has on the Demon, and the polished Genesis pipe looks really sharp on my Sprint Cat (that's a boat).

MJD

RE: West .50V1 bench run
 

MJD, that sums it up pretty good. No engine that will sit and idle all day can have the same performance potential as a pure racing engine unless it comes with timed fuel injection, close loop controlled. Some guy did a pretty exhaustive study of all the production engines to see which ones had the widest speed range and most power to weight...I think it was published 15-20 years ago in one of the mags. IIRC, the Webra .50 was in the top 3 or 4

RE: West .50V1 bench run
 

The old Aeromodeller review of the Conquest .15 RC lists it as having the highest specific power output of any RC engine to date. The Fox .74 always used to show up well on those tests, which are not skewed by the tender massage and methanol-doped bean oil they need to run.

I recall that test or at least a column on the subject. I believe the Sport Jett .46 when reviewed caused quite a stir with its speed range (6:1? >6:1?) and power output compared to the status quo.

Bob27s commented that the Jett .50LX and West .50V1 are timed for similar operating ranges. I'd imagine the SJ .50 and Webra Speed .50 are of a similar ilk as well. I'd still bet on the Jett but they're all fine engines.

MJD

RE: West .50V1 bench run
 

Your Weston sounds pretty good to me :D

I don't have any Westons but I've got a couple of .50GT's
Most I've seen is 14,700 with an APC 10X7 and stock muffler, on 10%, which hauls my Tower Kaos along nicely.

Mike...what is the I.D. of the Weston's venturi? Stock Webra .50 (and .61 Speed ) is 8mm

RE: West .50V1 bench run
 

west 50v1 9mm

RE: West .50V1 bench run
 

Weston new 52v1 available. The 50v1 machine tool has had it.
The new 52v1 is based on webra p5 engine. I think its 346g, With LOTS of mods. It too likes the 21k band so im told .

I believe weston sell more 'West' engines than webra.!

RE: West .50V1 bench run
 

I remember seeing a .25 sized DeHavilland Vampire on Weston's site a while back. It said it was coming soon...but I guess they dropped it? Anyone remember seeing it?

RE: West .50V1 bench run
 

Yeah, I thought I saw it in a news column in RCM&E, maybe some trade show coverage or something like that. I know I saw it. For some reason I think I recall the picture was noted as a prototype? Dunno.

MJD

RE: West .50V1 bench run
 

correct. I dont think it will be coming too soon, shame, vampire looked nice.

Mini-magnum and velocity could be april

RE: West .50V1 bench run
 

Unless you have scored of R&D staff, getting prototypes to production and market is never as small a job as one thinks. Let's hope it makes it through the process. Neat idea.

MJD

RE: West .50V1 bench run
 

Yer hope so,I liked that the tuned pipe was enclosed within the vampire.

RE: West .50V1 bench run
 

I ran the engine as it was yesterday, switching from an 8 x 9.25 to an 8 x 8.75. Now it was smack on and howling - the exhaust note took on that sound like the pipe would balloon if too thin. The jump in rpm confirmed it's pleasure with the shaft load - 20,400 from a grand less. I'm going to leave the pipe length exactly where it is, and fly with 8.75/9/9.25 pitchs and compare. Back into a Demon again. I'm so tickled with the way it is running, and how the new cowl looks that I might drop it in my #2 Demon which I am finishing up now as well. That one is covered in 3.7 ounce Stits and sounds like a tympani drum top and bottom, and is straight too. I have no qualms about stirring the stick hard with this one just to see what happens, there's no way I could fail it in the air; at least not due to the airframe anyway..

MJD

RE: West .50V1 bench run
 

sounds awesome, it should deliver.

What pipe sounded better to you on the 50v1, Genesis or mac?

RE: West .50V1 bench run
 

The Mac sounds nastier because it is unsilenced, so no comparison there.

RE: West .50V1 bench run
 

louder? I like the sound of that.!!