Cranking and running Norvel engines

RknRusty wrote:Ken's advice to whap it backwards works ten times better and I made a good chicken stick. At various needle settings it would crank and run really fast for about 2-4 seconds.

When combat with coroplast planes was really popular, one of the guys at the field flew NORVEL .15's. He would choke prime, flip a couple of times, attach the igniter and flick the engine backwards using just his fingers on the spinner. It usually started 9 out of 10 times. Quite a sight to see.

Rusty, just to be certain, nothing is blocking the spraybar? Have you added any extra head gaskets? This really helps some times. Are you currently using the stock Norvel plug? I know you mentioned Bernie's plugs. I haven't seen Bernie's plugs up close but I believe that they're Al Kelly Merlin plugs. I know that these can ramp up the compression and require even more gaskets. I also found that the majority of them are hot plugs. Using Merlin plugs I had the engine pre detonate while flipping, hence the need for more head gaskets. Small bursts of engine runs are certainly not uncommon. I'm wondering if you can place your finger partially over the venturi when it gets running. This would certainly assist in fuel draw, it can even flood the engine as well. Just a thought. I strongly feel once you get the initial run for a minute or two, all this will end. Ken

I believe back flipping became popular in Combat for all sizes as higher compression heads came into use...back when I had hair, and it had some color in it. :-)

If you get good at it, some like it better than over the top in the running direction. Be aware that it doesn't work as well with lower compression.

George

Wait a minute. I think George found the connection. Is combat the reason I have no hair? If your even suggesting yours has some color to it your luckier than I am. Ken

Ken Cook wrote: ...Small bursts of engine runs are certainly not uncommon... Ken

While reading this it occurred to me that the engine may be firing against compression and running backwards. That could account for the short bursts also.

A friend (who was also almost bald) once told me that God made very few perfect heads. The rest he covered with hair. :-)

George

gcb wrote:

Ken Cook wrote: ...Small bursts of engine runs are certainly not uncommon... Ken

While reading this it occurred to me that the engine may be firing against compression and running backwards. That could account for the short bursts also.

A friend (who was also almost bald) once told me that God made very few perfect heads. The rest he covered with hair. :-)

George

This is a great point and this condition could be caused or at least made worse if the engine is over compressed. You might want to try adding cylinder head shims and see if the lower compression helps. I know I am going to cause the torches and pitch forks to come out for this, but, on several previous Norvels I had similar starting/break in troubles and just resorted to an electric starter for the first few starts or until I can hand or spring start it. The Norvel starter spring is very effective too, but for break in I sstrip everything I can off the engine so it is pretty much only engine.

I hope your surgery goes well and you heal quickly, completely and as painlessly as possible. Hopefully you can still type with the other hand and join us here while you are on the mend.

Bob

Ken Cook wrote: Rusty, just to be certain, nothing is blocking the spraybar? Have you added any extra head gaskets? This really helps some times. Are you currently using the stock Norvel plug?.... Small bursts of engine runs are certainly not uncommon. I'm wondering if you can place your finger partially over the venturi when it gets running. This would certainly assist in fuel draw, it can even flood the engine as well. Just a thought. I strongly feel once you get the initial run for a minute or two, all this will end. Ken

The spraybar is clear. Holding the venturi assembly in my hand, I blocked each orifice and shot brake parts cleaner through it to confirm it flows through both sides and the spray hole. The needle is not bent nor does it have a broken tip.

Yes, the stock plug. Bernie's are mediums, but I have not changed it since the Norvel plug lights brightly.

Haven't tried partially blocking the venturi. I'll put that on my list.

gcb wrote:

Ken Cook wrote: ...Small bursts of engine runs are certainly not uncommon... Ken

While reading this it occurred to me that the engine may be firing against compression and running backwards. That could account for the short bursts also.

A friend (who was also almost bald) once told me that God made very few perfect heads. The rest he covered with hair. :-)

George

As a long time Cox guy, I always associate short fast bursts as being too lean to sustain running. I'm assuming that's true with the Norvel too. After a few short bursts in a row, I open the needle another 8th of a turn richer and try again. Last night I would do this until the needle reached a point where it quit firing and flooded.

I made a point of noting the air flow was in the correct direction, assuming it runs the same direction as the common Cox, CW as seen from the cockpit. In other words, the right direction to fly a plane. I'm using the same Master Airscrew that I fly on all of my planes.

I obviously have an imperfect head.

EDIT: I'm using 3 shims. I'll try 5.

fit90 wrote:I hope your surgery goes well and you heal quickly, completely and as painlessly as possible. Hopefully you can still type with the other hand and join us here while you are on the mend.

Bob

Thanks, Bob, it's simple carpal tunnel release. And with a handful of the right pain killers, I'll be typing fine. Just mayne more entertaining.

Well Bob, you wont be torched or pitched to bad, because I use a electric starter excusively and have for 20+ years. It takes experience, a trained eye, ear and feather touch when using tho' or you can really do some damage very quick. My old 1980's Astro Flight 1/2A starter is still plugging along. My new Sullivan Hornet 1/2A is a bit to strong for 1/2A start work, so it gets used sparingly. I think I could start my OS 55Max with that thing. It does save the fingers and frustration of flipping a new motor all day long for break-in. It allows you to clear a slight flood quickly and assuredly just by pulling the head and bumping it over with a rag over the cylinder to catch fuel. I usually take the head off, roll it over to BDC, pull the test stand out of the vice, and shake it upside down to see if any drop or streams of fuel run out, then reset everything and try again.

I did not have good luck with the Freedom plugs, some folks did, but I did not. A very delicate plug those Freedom's. They all (new and old stock) popped rather quickly even at 1.2-5 volts so I ended up switching to a Galbreath/Nelson head plug setup. This allowed me to loosen the plug very slightly before starting ,,dropping the compression,, and then once it fired off I could tighten down the plug and hear the motor change tune/sound as that compression came back again, without having to pull head coppers. Some folks had really good luck with the Freedom's, but mine did not last thru the first 4 oz of fuel if that. Break-in plugs usually don't last and should be changed out afterwards because they are bombarded/coated by tiny bits of break-in metals and extra fine shavings and that in turn changes the heat range slightly and sometimes makes a huge difference on how they run.

Keep at it Rusty, it's a learning experience, you will succeed. Hope your surgery goes uneventful.

Now we're getting somewhere. I took Bob's advice and added 2 more shims for a total of 5. I set the needle at 2.5 turns and flipped it. Gave it a little prime, which always seems to be a mistake. But after I cleared it, on the next flip it took off and ran fast. I reached for the needle to add some more but it died as soon as I touched it. Still at 2.5, one more flip and it ran for another good 10 seconds and cut off as soon as I reached for the needle. Then it was time to go cook supper, so that's how she sits.

When I go back out, I'll add another shim or two and try again. I really thought i had it there for a minute. I have until tomorrow afternoon before I have to leave for the medical center. So I'm going to turn in early tonight and get out there for a fresh start tomorrow. Boys, I believe we've about got her done.

I'm still uploading last nights antics with the little bugger. I'll go ahead and post it when it's on the tube, maybe there's a clue in there somewhere. It's 7 riveting minutes of flipping and braapping with my customary commentary. I hadn't noticed until the video how much the thing smokes. Looks like it'll be about an hour to upload.

That sounds a bit odd Rusty in regards to the smoke. I can see if residual oil is in the case it can be problematic. I'm faced with this constantly as I use air tool oil for after run in all my ball bearing 1/2A's. I pull the plug and flush with fresh fuel, blow it out and run out the prime prior to getting it ready for flight. What percentage oil is in the fuel ? I know you were not the biggest fan of Sig fuels as I recall. This is a standard diet on all my Norvel's. I do believe that 20% oil content is what Sig provides. I've used Powermaster 10/22 and this seems to be a bit much on oil as it just goes everywhere. Ken

PV Pilot wrote: ... Break-in plugs usually don't last and should be changed out afterwards because they are bombarded/coated by tiny bits of break-in metals and extra fine shavings and that in turn changes the heat range slightly and sometimes makes a huge difference on how they run...

When metals and other impurities coat the platinum element it can get so bad that the methanol can not maintain a catalytic reaction. Symptoms are when RPM drops off after you remove the booster. NORVEL used to advertise that because NORVEL engines run cooler than large ones, impurities in the fuel and even rubber in a fuel bulb could foul a plug.

I got my first NORVEL engines at the pre-revlite era when they were switching to the "Freedom Plug". One of the improvements with this plug was that you could use a NiCd booster with it. A booster would not fit on the old plug and they required more power than a single NiCd could supply. My first two engines came with old plugs installed and "Freedom" adapter and plug in the box. I have used the old plugs with a Cox clip and two "D" cells. They seemed to perform well. Bear in mind that I am a sport flyer and have not tried these in competition.

George

My fuel is 20% oil, pure castor. Sig kept turning all of my glow plugs white and frosty looking. As I said earlier, after adding 2 more shims today, it was almost there with several 10 second fast smooth runs. In the morning I'm going to add 1 or 2 more shims. It seems like it's almost there now.
But since I made the video last night I figured I might as well post it in case y'all see something really dumb I'm doing wrong.

Here it is:



The next video will be it screaming and me watching it sing.

Rusty, these engines draw very little vacuum for suction. Therefore air leaks are more critical.I'm not suggesting you have a leak as I think we ruled that out. They need to run in the mid 20k area to maintain a steady vacuum. It appears and it is hard to tell from the vid that you have a fairly long fuel line from tank to engine. I certainly wouldn't hesitate to raise your tank 1/4" or more just to assist in fuel feed. It may flood but your pinch off device is right there in the event it starts to gravity feed. It seems as though your needle isn't quite open enough. The longer fuel line could be conflicting this however. In addition to shortening the fuel supply tubing, I would try and run your tubing as straight and level as possible. for now. All this may be meaningless but it may just help until the engine gets a few minutes on it. At one point, the engine wants to run longer then it leans out and the whole process begins once again. I would start fresh with some of the changes I suggested.

I would place my finger over the venturi and pull 1-2 revolutions of the prop watching the fuel line to see the fuel is coming up to the spraybar. All this being done with the needle open a bit. If the engine is flooding, it should really be coming out of the exhaust as well. Then we know it really is flooded which is not a bad thing. Clear the flood and the case with your pinch off device in place and try again. Close the needle down a bit and try again. If your getting an intermittent run where at one point the engine wants to run for a few seconds, try and flip up until the point your getting that longer run. Pull one revolution of the prop with your finger over the venturi and resume flipping and see if that will get her going. Ken

I also just noticed something else, in your post. These engines don't require all castor fuels. It will hamper break in and not allow the engine to come up to the correct temp. The cylinder walls are extremely tapered. Once the heat gets it hot they expand allowing the walls to be straight up and down parallel to each other. Your smoking now confirms this. The high castor is also raising your compression through the roof which is probably why the additional shims helped. These use a 50/50 mix of synthetics and castor. These engine are critical for the first few minutes of break in. If the temp doesn't come up correctly the cylinder will maintian it's taper which causes high stresses on the rod especially. Ken

Ken Cook wrote: I also just noticed something else, in your post. These engines don't use all castor fuels. It will hamper break in and not allow the engine to come up to the correct temp. The cylinder walls are extremely tapered. Once the heat gets it hot they expand allowing the walls to be straight up and down parallel to each other. Your smoking now confirms this. The high castor is also raising your compression through the roof which is probably why the additional shims helped. These use a 50/50 mix of synthetics and castor. These engine are critical for the first few minutes of break in. If the temp doesn't come up correctly the cylinder will maintain it's taper which causes high stresses on the rod especially. Ken

CRAP!
I gave all three of my Sig fuel bottles away. I had some 20%, 25% and 35%. I was blaming them for frosting my glow plugs.
So I have to wait until I get new Sig fuel. I had read where all castor was okay, so I was using my usual favorite mix.

But thanks for the info.

I'm not saying you could never use that fuel. I just wouldn't use it initially.I would also use it sparingly as varnish will readily take place. I suppose one of the benefits of all castor is the fact that it's so dense it collects the heat like a heat sink and exits via exhaust. In turn we want to do the opposite here. The viscosity of the all castor fuel could certainly change the needle as well. These engine are even sensitive to changes throughout the day that you probably wouldn't of recognized using Cox engines. As the temp goes up the needle will have to be screwed in and when the air gets cooler towards the evening you'll have to back it out. Ken

I'm reading all sorts of conflicting fuel endorsements from Surfer Kris and others. I'll go ahead and get some Sig though. That stuff is slicker than owl s#!t.
Now I'm going nighty night. I had planned to do that early and now it's late. See ya tomorrow.

Man Rusty,

I have been there and I feel your frustration. I hope you get it sorted. I am going to stick with my TD's........ I came across a NIB Norvel recently and promptly sold it to John Boy for that very reason.

I think they are great engines it's just I don't have time for all that flipping in the field.

Ron

RknRusty wrote:
But since I made the video last night I figured I might as well post it in case y'all see something really dumb I'm doing wrong.

It looks like you are turning the prop in the wrong direction? This can work but it will make the engine run in the wrong direction. The method mentioned earlier here was to bump on the compression only and the engine fires and runs in the right direction. Personally it has never helped me on the little ones...

If the engine is brand new, then it helps to preheat the cylinder to remove some of the pinch at TDC. A spring starter also helps to give a little extra spin on the prop to keep it running. 20% all castor and 10% Nitro is all I use for my Norvel engines. You can also try a smaller prop, a 5x3 is a better match for these engines that do like to rev, while a 6x3 is a little too much load.

There are also two different glow heads out there for these engines. You'll want to have the hotter version which is recognizable on its rounded tip where the glow driver goes. There is a colder glow head that has a more squared off pin and a little smaller diameter where the clamp goes.

cribbs74 wrote:Man Rusty,

I have been there and I feel your frustration. I hope you get it sorted. I am going to stick with my TD's........ I came across a NIB Norvel recently and promptly sold it to John Boy for that very reason.

I think they are great engines it's just I don't have time for all that flipping in the field.

Ron

Yawwwwn, hi Ron, just got up for a few minutes to shake off wild dreams of tiny rotating assemblies and combustion chambers. Which one of our fellow peeps is it we call John Boy? Yeah, I fully believe they're great engines, but I'm thinking by the time it gets to the field it'll be easy to crank. If it's as easy as a Tee Dee it'll be quite a marvel. I never knew anything was as easy to crank as a Tee Dee on a bladder. Just set the needle to where it was a week or a month ago, a quick bump of fuel and zoom, off to the races. Not even the best reedie Bee in the world can do that first time every time. It took me a little while to get the hang of that too though. I showed them my Baby Flite Streak over on the little NV Norvel forum. I bet they're watching that in disbelief... a Cox? Really? Must be some freak of nature. Thanks, Bob, Fit90 for introducing me to those.
This thing will not kick my ass. I do not take crap off of machines! I think I've said that recently.

Surfer_kris wrote:

RknRusty wrote:
But since I made the video last night I figured I might as well post it in case y'all see something really dumb I'm doing wrong.

It looks like you are turning the prop in the wrong direction? This can work but it will make the engine run in the wrong direction. The method mentioned earlier here was to bump on the compression only and the engine fires and runs in the right direction. Personally it has never helped me on the little ones...

If the engine is brand new, then it helps to preheat the cylinder to remove some of the pinch at TDC. A spring starter also helps to give a little extra spin on the prop to keep it running. 20% all castor and 10% Nitro is all I use for my Norvel engines. You can also try a smaller prop, a 5x3 is a better match for these engines that do like to rev, while a 6x3 is a little too much load.

There are also two different glow heads out there for these engines. You'll want to have the hotter version which is recognizable on its rounded tip where the glow driver goes. There is a colder glow head that has a more squared off pin and a little smaller diameter where the clamp goes.

Hi Kris, you caught me dropping your name, I see. The first day I spent flipping it like a Tee Dee. Someone suggested back flipping it and it seemed to work better for me and my wonky shoulder. It'll kick off backwards and then reverse itself and run the right way. I couldn't think of anything that would hurt it doing this as it only runs slowly backwards before it hops up and turns the right way.I kept knocking the screw loose flipping it forward. It has a crappy soft philips in it. I ordered some new black oxide screws and a spring too.

I put a 6x3 on it after I read the directions at NVEngines.com. I might put a smaller one on it next time I try. I don't have the patience to wait for new fuel, I'm going to keep trying with what I have. Thanks for chiming in on it.