West 50V1: what plugs do you use?
 

Hello guys, as I wrote in the subject I'd like to know which brand and type of glowplugs are you using on the West 50V1.
I have this engine on my MagnumR with the genesis pipe and the combination is really awsome... this is my second Magnum (I had a first generation before this one) and after 150 flights (more or less) I still haven't managed to find the right plug...
I've used OS 8, 5, F and Rossi 5, 6, 8 so far... I run 15% CoolPower and APC 9x6 and 8x10 props...
The plug that has lasted longer up to now is the OS n°5, doing about 7-8 flights before quitting... I'm getting tired of changing plugs!
Thanks for all your info,
Mauri

RE: West 50V1: what plugs do you use?
 

I run cheap Tower Hobby plugs and they last seasons... My Magnum is 4 or 5 years old has hundreds of flights and after it got broke in I don't think I've changed the plug...

Cool Power 10% and a APC 8X9 or 8X10 prop...

I run it slightly rich, decent smoke trail. If you lean it out for that extra half percent of RPM it will shorten the life of your plugs....

RE: West 50V1: what plugs do you use?
 

I ran the OS5 car plugs, they lasted the best, I think I generally only got about 3 or 4 runs on them though. Most of the others wouldn't even give me one full run, and yes, I always ran it slightly rich :P

RE: West 50V1: what plugs do you use?
 

I have about 30 flights on mine, all on the OS #8 I first installed. Still idles and transitions fine so the plug is healthy. I have no idea why the others are blowing plugs, but I would look at the usual suspects for that problem.

MJD

RE: West 50V1: what plugs do you use?
 

I use K&B1L plugs without any problem. I am Using 10% Morgan Omega (Castor/Syntetic Blend fuel) Prop is APC 9x7 I tach it at 20,000RPM

I think your problem is that you are leaning to much your engine or maybe the problem is the 15% nitro, since this engine is intended for low nitro.

Isaac

RE: West 50V1: what plugs do you use?
 

Thanks for your inputs...
I might try to lower the nitro percentage although I've often read of people running 15% nitro... how much oil would you suggest? 15%-18% synthetic?
In these days it's getting really hot here in Italy and I usually fly at about 25°C or more. In any case I've been throwing plugs away during winter time too...
It's funny to read of people with my same problems, burning plugs quite often, and other people who are running the same plugs for years on a same motor and same prop as mine!!!
On other glow engines I haven't ever had this problem, from slow four strokes to high revving ducted fan engines such as the Rossi .53 and .90...
Well... I'll try a lower nitro fuel and I'll go to my LHS and get ann assortment of plugs I suppose!
Mauri

RE: West 50V1: what plugs do you use?
 

I'd suggest 10% nitromethane, IIRC it is the recommendation with the motor but I don't have the literature at hand at the moment. I use 18% oil, 20% castor/80% synthetic, although Weston would tell you to skip the castor and go straight synthetic. If you have some 10% Cool Power, maybe give that a shot. Who knows?

How much are you backing off from peak rpm on the ground? I know you said you don't run lean, I am just curious.

Are you running the stock header length or has it been shortened?

MJD

RE: West 50V1: what plugs do you use?
 

In ABC/ABN engines, I always use Castor/Synthetic Blend fuels.

Better go with the higuer oil conten for better lubrication at 20K+RPM

I think that maybe since this engine is designed for low nitro maybe the 15% nitro and the engine overcompresion is killing his plugs.

Isaac

RE: West 50V1: what plugs do you use?
 

After peak RPM, holding the plane vertical, I open the needle 1-2 clicks... in this way it's a little rich on take-off... with a new or nearly new plug it then reaches it's best in the air leaving a light trail behind...
Once the plug has been flown, lets say 5-6 times, the engine doesn't seem to reach the same rpm in the air and I have to close those 1-2 clicks again... and finally the plug quits!
When I check the plug after one or two runs I usually find that the coil is deformed and sometimes partially out of the plug itself!
The header and pipe are still stock length as I have never tried the 8x8 prop, I like the speed of the 8x10!
I'll try 18% synthetic/10% nitro next weekend.
Thanks, Mauri

RE: West 50V1: what plugs do you use?
 

I forgot to say that the plugs always quit at the end or near to the end of the flight... they at least let me enjoy the run!
Mauri

RE: West 50V1: what plugs do you use?
 

You are running it too lean, the symptoms/causes are all right there in your descriptions. I don't think the problem is a mystery.

Two clicks on that needle is not much, it is a fairly broad needle, and I have needled mine quite a bit on the tach to see this. I strongly suggest you spend a few minutes on the ground with a tach, and bring the engine to peak, then back off until you get a 500 rpm drop or so. Make a mental note of the needle sensitivity. Fly there and see what happens. The fact that you are losing the plugs at the end of the run tells me that the leaning that occurs at the end of the tank is pushing it right over the top and killing your plug. What tank are you using - clunk or bladder?

I also suggest you try the 10% nitro.

MJD

RE: West 50V1: what plugs do you use?
 

Yes, I understand what you mean but... this thing is meant to be ballistic..! if I richen it more than those 1-2 clicks the whole run is affected and the top speed drops to that of a good low wing trainer... it gets quickly boring that way... I find that my needle is very sensitive and those 2 clicks make a whole lot of a difference.
The tank is with the stock clunk, stock tubes and I haven't fitted any filter.
I know that running richer would save my plugs and make them last a little longer, but then the plane will not fly as it should, I think...
That's why I askled your help, and maybe having less nitro will be the solution...
I'll try in any case to use the tachometer and set the rpm as you suggest.
Thanks!
Mauri

RE: West 50V1: what plugs do you use?
 

Guys,

What about adding another head shim to decrease the compression ratio? Would that help him out?

I do have to agree with MJD though. His explaination does make sense.

~Mark

RE: West 50V1: what plugs do you use?
 

Interesting, I do not find my needle that sensitive. I understand what you are saying and why. I have seen good performance on broader adjustments than you imply.

I agree Laserbeam, I still say try 10% in deference to the compression ratio, IIRC 10% is about the limit for this engine and a lot of this could be due to that. Someone else will have to help out on this - what is the effect on needle sensitivity of slight over-compression? I've not had to deal with it enough to know first hand.

I wonder, failing the above, and I am reaching a bit here - with the lean runs, or possibility of lean runs you've had, I wonder if you're a bit down on power, and thus I wonder if the 8-10 is a bit too much load. I may also suggest, that if you have one maybe try an 8-9, or even the 8-8 to see if the lighter load helps. While it is true that the 8-8 is optimal with a shortened pipe, in this case and if the engine is down a bit you are not loading the engine at the bottom of the pipe tune, but over it, and that won't cause any grief. It just means you'll be a few rpm short.

Some knowledge of your static rpm at peak and clicked out two turns might help too.

When it is behaving, the West .50 is an amazingly easy engine to handle for it's performance. To me that suggests the answer is likely not complicated.

Best of luck, hope you get this sorted out. I bet Bob27s would see through all these symptoms in a heartbeat. Maybe try a PM?

Once you are getting some results, I'd suggest trying out a bladder tank.. I have never run mine on a clunk, but others do and they apparently work for them. They're a piece of cake to handle and sure make those runs consistent.

MJD

RE: West 50V1: what plugs do you use?
 

If you are using the stock tank, and fly beyond 1/3 of the fuel remaining in the tank, I can almost guarantee you are getting a lean condition at the end of the flight that is toasting the glow plugs. It will suck an air bubble, and that is all she wrote.

RE: West 50V1: what plugs do you use?
 

Oh man with the answers...

What do you make of the needle sensitivity Bob? Mine is nothing like that, it is reasonably broad and easy to adjust. Will the 15% nitro in combination with "European" compression standards cause touchy needling? Weston does recommend 10% now that I look.

Or is this all as simple as the clunk issue and 15% versus 10% is no big deal?

MJD

RE: West 50V1: what plugs do you use?
 

Senstive needle usually indicates the pipe is too short, or the prop is too big. Hard to get the engine to needle properly when its hunting to find the right rpm. (short pipe syndrome).

The pipe length is probably ok..... the engine unloads in the air, and probably easily jumps up on the pipe.

The trick is, at launch, you are dealing with what we have for Q500 and QM40 with a "big" prop -- your needle setting on the ground is a crapshoot.... you do not see a "pipe" stable rpm - it may provide a false peak, and you will tend not to back off on the mixture properly. The engine unloads in the air,.... next thing you know you have a lean run or a real fat run because you missed on the needle setting. So usually, most of us use props that run at rpm high enough so that they pre-stage cleanly on the pipe, and the engine is easy to needle. Those who are adventurous and want a record speed will put on a bit more prop, and trust instinct (and practice) to know where to set the needle (then pray it doesnt load up or overheat prior to launch).

Remember, setting the engine slightly rich on the ground does not mean the engine stays "rich". Fuel is power - more fuel is more power, under the right mixture conditions. When the engine jumps on the pipe in the air, it gains 1500 rpm, and will require more fuel. So if the engine is not just a bit rich at launch..... it will tend to get hot or go lean once it jumps on the pipe.

In this case, the needle is probably pretty close, or he would notice the lean condition earlier in the flight. But the engine is howling, and that one air-bubble sucked at the end of the tank will cause a temp spike and toast the glow plug. (I've burnt enough plugs - before I went to bubble tanks)

Real easy way to avoid the sensitivity is to drop one prop size. Bring the prop to the existing pipe length. And obviously, lengthing the pipe a 1/4" will work just as well, and keep the existing prop.

The heli guys run the weston 50 on 30% ...... same head setup. So fuel does not appear to be a problem. The difference between 10% and 15% is not that huge.

Adding .005 to the head clearance usually does not affect how the engine runs that much, until you start getting into REAL high compression and higher rpm engines.

The Weston is tweeked, but to about the same extent the Jett 50 is.... and I know that a shim under the head there will not stop an engine from tosting plugs, regardless of the fuel or prop.

RE: West 50V1: what plugs do you use?
 

Thanks Bob, good info - man your wrists must hurt from all the typing sometimes!

I ran the stock pipe until recently, and mine needled easily on 9-6, 8-9 and 8-8 props. Never bothered with 8-10 due to reports of dodgy launches.

I launch mine fairly fat, and it indeed unloads and howls but still has a visible smoke trail, and I don't blow plugs (knock on wood). The engine is still tight at TDC cold, I'd say that is a good sign after 30 or so runs.

MJD

RE: West 50V1: what plugs do you use?
 

Thank you bob27s, MJD and all the others... this has been instructive.
I'll come back next week with more informations and some numbers after trying out your precious advice...
Mauri