Cranking and running Norvel engines

Ken Cook wrote: I subscribe to the you can never have too much power theory. I actually fly my Baby Flitestreak with Norvel power. I'm not on pressure mind you, but there's a lot to do to keep things mild. Propping correctly is certainly the best as you can let the engine rev and not allow the plane to go a zillion miles an hour. I certainly feel the APC 5.5 x 2 would do the trick as I use a similar setup on another model of about the same squares. Adding additional head gaskets is another good tuning device. I know your limited for space, flying on longer lines is a very simple adjustment to slow the plane down. You can also keep your nitro down, this can be problematic at times using pressure as the plug wants to cool immediately. Choking down your venturi area can keep things mild as well and this can be done several ways. Seeing what looks like an r/c carb on there this would be very easy to do. You could make a piece of music wire hook going from your engine mounting screws to the throttle arm on the carb. Ken

All good ideas. I have a spare CL venturi with a fine thread NV in it, so no throttle and I'll be using pressure to feed it. I also have a 6x2 APC which will be an even safer starting point. I haven't got enough flights on the Streak yet, so I'm going to continue to fly with the Tee Dee .051 until I feel totally confident with it. I did pretty good on 35' last time, you probably saw the video in Microflitedude's tube channel(hope to have it in my channel soon). I don't have any good Streak movies in my channel. Next time it flies it will be on 40' which will be a little better. After I get to the point that I know I can handle extra power I'll put the Norvel .061 on it. I might try it just for kicks on the Stuntman23 which is my designated beater and tough as nails. I wouldn't cry if I splintered it either.

If I take the Tee Dee .049 off of the Stuntman, I may mount it on the Li'l Satan with one of the screw-on radial TD mounts. That should be a pretty wild ride too, but the Satan is a very well behaved plane.

My son wanted to hear it run, so I got the new mount filed and fixed up to fit the Norvel and starter spring. The venturi has a new gasket as well as the needle. The venturi still moves so it needs a thicker gasket but it works fine when my hands are off of it. I cleaned out the fuel tank and checked the prop, APC 5.5x2. It started on the first flip and tached at a solid 25.4K after it warmed up. I ran it down to a rich burble a couple of times to make sure I didn't overheat it, also to make sure the needle worked right. Sounds good. Still with three shims in the head. I'll try two next time.

I took another shim out, leaving two. Same prop as last night, APC 5.5x2, and it held solid, and I mean steady 25.9k RPM. I fiddled and fiddled and got it to bump off of 26k a couple of times but it wouldn't hold it. By then I was running on the dregs of the fuel tank.

I had been worried that I had over worked the cylinder liner with all of my flipping, brraaping and fumbling when I first started breaking it in. But now with only two shims, after it cooled off the tightness at TDC is back. I'm glad about that.
I love to hear that high shrill wheeeeeeee... It doesn't sound like a Tee Dee at all.

This is with spiked Glowplugboy, so it has about 21% nitro and 20% castor. I don't have any reason or need to try, but if I had some 35% fuel, I wonder how fast it would run. I guarantee it would be faster than I need it to.

Bottom of the tank leanout,,for your 26K probably

I've been running the Norvel I have shown in my picture above. The engine was new even though it doesn't appear that way. I truly believe all the crank fits in these engines are way too tight. I took the engine apart and sent it my machinist friend. He puts .002" clearance in the crank using a Sunnen honing machine. It's not uncommon if you run these engines hard that they can pick up aluminum and they can gall the shaft. I've never had a Norvel get me into the 30K range. I believe however I may be close with this one as my launch rpm today was 28500K. The prop is 4 3/8 x 3. The .061's are terrific running engines. Ken

Ken,

Is that Norvel an AME or Big Mig. My sole remaining AME with a polished crankshaft, Galbreath head/Nelson plug and on backplate pressure used to turn an APC 5.7X3 cut down to 5X3 28k on the bench. I bet that with a more lightly loaded prop 30K could be done. I have some purple props from kittingittogether.com that are about 4.8X2.8, or so I've been told, that I think would put this engine over the 30k mark. Gotta give it a try some day.

Bob

Bob, this is the Big Mig. I do have a new AME sitting here and I'm getting impatient. I want to to see what this will do. The glass props are the ticket. I have 3 of the purple props. I find them to work great on my VA's and Profi's but when I stuck them on my Stels and Norvel .049's they didn't give me the drive. I do however have a amber colored one that's slight larger diameter that does work good. I'm currently trying to get a order for these together. Most suppliers aren't budging on the 200 minimum order deal. My launch rpm is 28500, this is the richest I can run the engine without it quitting. I'm flying my son and his is .049 so I'm trying to keep the speeds as even as possible. I'm on the stock plug with 2 head gaskets and 10% fuel. Ken

PV Pilot wrote:Bottom of the tank leanout,,for your 26K probably

Might have been. It never sucked air before I pinched it off but it was getting close. The engine was not pulling the fuel uphill, and it was still spilling a steady stream when I pulled the tube off the engine to check. But maybe without the weight of extra fuel it started to lean out. I don't know. It's only had a total of 8 0unces run through it so far, so I still rich it up briefly every minute or so to make sure I don't overheat it. I should probably keep exercising it for a while, besides I'm not ready to put it on a plane yet.

As soon as I feel like it's run-in, it'll be time to start running-in the MP Jet. I have the methanol and castor ready to mix for it. It's a stiff little engine too.

RknRusty wrote:

PV Pilot wrote:Bottom of the tank leanout,,for your 26K probably

Might have been. It never sucked air before I pinched it off but it was getting close. The engine was not pulling the fuel uphill, and it was still spilling a steady stream when I pulled the tube off the engine to check. But maybe without the weight of extra fuel it started to lean out. I don't know. It's only had a total of 8 0unces run through it so far, so I still rich it up briefly every minute or so to make sure I don't overheat it. I should probably keep exercising it for a while, besides I'm not ready to put it on a plane yet.

As soon as I feel like it's run-in, it'll be time to start running-in the MP Jet. I have the methanol and castor ready to mix for it. It's a stiff little engine too.

Yup, I try to error on the side of caution, for the tank. Keep it a bit rich on the end on the tank. Have always done that,,or tried to. I envision white hot combustion chamber when it pulls easy rpms on the end of the tank, then it dies and it heat soaks even more.

Have any of you guys tried a Master Air Screw screw prop on your Norvel with the starter spring? I just cut down a MAS 6X3 to 5X3 and put it on a Norvel and the prop and the spring did not get along at all. Hopefully I just need to adjust the spring. The engine really liked the prop.

Bob

PV Pilot wrote:Bottom of the tank leanout,,for your 26K probably

Point proved. I put 3 ounces in the tank today and it ran steady at 25.5k, never approached 26k. It sings a steady happy song and starts on the first flip every time. All other test conditions were the same as before, even the weather.

fit90 wrote:Have any of you guys tried a Master Air Screw screw prop on your Norvel with the starter spring? I just cut down a MAS 6X3 to 5X3 and put it on a Norvel and the prop and the spring did not get along at all. Hopefully I just need to adjust the spring. The engine really liked the prop.

Bob

Just the APC since I got it really running. I have a couple of MA 5x3s so I'll try one tomorrow and see what happens.

Ken Cook wrote: I removed my venturi this afternoon. I was able to press a fine threaded spray bar into the case after I opened the hole. The stock spray bar is .114". The other end is .009". My theory is the knurling on the spray bar probably has swelled the metal which is the difference in measurement. This wasn't a issue to Cox probably due to the molded plastic backplates they were pressed into. The closest number drill I had measured .1085". I was able to carefully and accurately open the holes as the bit just followed what was there for the venturi through bolt. I then used a piece of cylindrical steel stock approx 5/16" round and chucked it up in the drill press. I placed the case into a v block and supported it. I used the drill press to press the spray bar into the case. The knurling on the spray bar worked great and will prevent it from spinning. The spray bar has a shoulder on it that allows the spray bar to stop. The hole in the spray bar isn't quite centered but for pressure will work close enough. In the event you want to go back and put the stock venturi back in, press the bar back out and the stock bolt will still work. For running pressure, I doubt your going to see any better performance than this. Generally, my launch rpm is about 26500 using a APC 4.6 x 3. Ken

I just gave this a shot on a Norvel .061 AME I won from ebay. The engine had very little run time and some fairly bad crash damage. The carb was broken in half, the drive washer and plate were missing, the spinner and spinner screw were damaged beyond repair and the threads in the crankshaft were damaged beyond repair. This all made this a great engine to experiment with. Anyhow, after replacing all the bad parts except the carb I followed Ken's example and also included a pressure tapped backplate and Galbreath head with a Nelson plug. The only difference was that I angles the hole inthe the spray bar downward about 30 degrees pointing backwards. The engine started right up and ran great. It needs some more running in but sounds like it should be a good performer.

Thanks again for sharing this nice little trick with us Ken.

Thank you,

Bob

Wow, sounds like it had led a rough life. It's great that you could resurrect it.
I cranked mine a couple of times today and it needles and stays at 25.5k. I've run probably 12 ounces through it. What do you think, should I call it run-in, or give it a few more runs before I dismount it?

If it starts easily, needles well and holds a leaned out needle setting through an ounce or more of fuel it is ready for service. Do not be surprised if at some point after it goes through a couple of quarts of fuel it seems to loosen up and spin even faster. This is not uncommon with Norvels.

Any plans to start on the MP Jet yet?

fit90 wrote:If it starts easily, needles well and holds a leaned out needle setting through an ounce or more of fuel it is ready for service. Do not be surprised if at some point after it goes through a couple of quarts of fuel it seems to loosen up and spin even faster. This is not uncommon with Norvels.

It still doesn't like to start with a finger flip but it does crank on the first try or two with the spring. It holds a needle, though I haven't let it run for a whole ounce without backing it down about 3 times. I'll check that. I ran 2 more ounces a little while ago.

I put the muffler on because I wanted to see what that was like, but I haven't run it yet. I figured I would hook up a pressure line since I've never done anything like that before. Just to see what happens, how it acts. Is there any reason for a check valve inline? It seems like that would change the mixture if the pressure builds faster or slower than the fuel disappears. Maybe nix the check valve idea?

fit90 wrote:Any plans to start on the MP Jet yet?

I'm planning to make a wood mount for it this week and crank it up. I'm also curious to see how my other planes run on zero nitro fuel. Just a shop test, I'm not going to fly with the stuff.

Rusty,

If you run the muffler on the Norvel you will notice a big change in the needle valve setting and a BIG drop in RPM. I just ran a Big Mig .061 with the Cox yellow 5X3 and got a 2500 RPM drop when I tried the muffler. The noise difference was noticable at one to two feet, for what that's worth. I don't use a check valve for muffler pressure. You can give it a shot and see if there is any difference between having it and not having it. Keep us posted.

Bob

Her is the new (old) baby! Thanks again Ken. It was very simple to do and so far it appears to be very effective.

Rusty, the truth is when using muffler pressure your engine is going to run richer hence slower. As the head pressure on the tank lessens the mixture also becomes leaner and leaner throughout the flight. Muffler pressure increases witht he engines speed. A simple test is to remove the muffler pressure line when the engine is running and you'll most certainly see the engine rpm's increase. Most Norvel's don't require muffler pressure. Some AME versions have extremely large venturi's and therefore do require either muffler pressure or backplate pressure. In my opinion the muffler only complicates things due to being to restrictive and it also retains too much heat. No backcheck valve is required using muffler pressure. The best possible run your going to achieve using a tank is one that's setup with a uniflow pipe. In the event the fuel is foaming due to vibrations on the nose of the plane all bets are off and uniflow will absolutely not work. This is one reason we give our fuel a shot of Armor All in the fuel. Try it sometime. If you have fuel in a clear bottle, shake it until it foams it looks like soda that's been shaken. Put one squirt in the fuel and try again, you would be surprised at no bubbles. I know your using bladders but in the situation of tanks, the uniflow is the best choice as it can be run in all 3 configurations, muffler pressure, open atmosphere uniflow pressure, and also standard suction. All this can be achieved by capping certain vents. Ken

Be careful of too many additives. NORVEL used to recommend certain fuels because they had NO additives. Apparently the engines ran too cool to burn the additives so they instead fouled the plugs. They even recommended non-rubber fuelers...same reason.

In reading about the mufflers, I just wonder if they "tune" at a particular RPM? Remember the advertisement pictures where the mufflers were backward with the exhaust in front. Anyone try them that way?

George

I ran it today with the muffler on it. It didn't make much difference in the noise, but it didn't smoke up the shop anywhere near as bad. I left the pressure port open so it was blowing out of both holes. It slowed the engine by 700 RPM.

Regarding yesterdays question about when to declare it broken-in enough to use, I ran about an ounce and a half through it, and once set, I never touched the needle. It held 24.8k, never wavering for the entire run, which must have been ten minutes or more. Without the muffler it runs steady at about 25.5k.

As far as anti-foaming additives, I've never felt the need as I've only run Bees, mostly tanked, in the past. Foaming might explain some erratic runs that I could find no reason for. But then tanked Bees will do that, I'm convinced, for no other reason than just to infuriate me. Therein lies my new found love for bladder-fed Tee Dees. But recently I flew my PT-19 with its new Killer Bee and I saw the fuel in the tank foam. So maybe I need to bottle up a pint of anti-foam treated fuel for my remaining Bees.

Ken Cook wrote: ........ A simple test is to remove the muffler pressure line when the engine is running and you'll most certainly see the engine rpm's increase. Most Norvel's don't require muffler pressure. Some AME versions have extremely large venturi's and therefore do require either muffler pressure or backplate pressure. In my opinion the muffler only complicates things due to being to restrictive and it also retains too much heat. ......... Ken

Once, while flying, the muffler endcap popped loose (luckily, I didn't lose it, but have since taken to JB Welding them in place). I couldn't really tell exactly what had happened, but the plane seemed to fly forever --- it was a C/L engine on a R/C model. With the tank I was using, I usually got 7 to 9 minutes, so hanging on at WOT for much longer wears out an old man.

I found out what had occurred when it ran out of fuel --- apparently losing muffler pressure leaned the engine and extended the runtime. I hadn't considered the cooling effect, but even though it leaned out, perhaps the lower backpressure dropped the heat level and the engine was happy enough. I was just glad it finally quit.

RknRusty wrote:

As far as anti-foaming additives, I've never felt the need as I've only run Bees, mostly tanked, in the past. Foaming might explain some erratic runs that I could find no reason for.

I expect if we could see into a Bee tank, we would see extensive foaming. Since there is no way to isolate the fuel tank from the engine, foaming and probably some boiling of the methanol likely happens.

I'm one of the old school practitioners that still pads the tanks and wraps my receivers and batteries in foam. Although I realize that the now standard surface mount boards don't suffer from the tuning fork effect of the old through-hole technology, I still cringe when I see a RX mounted to the side of the fuselage with double-sided tape. My planes usually have enough foam to house a nest of mice.

I never believed the statement claimed from using BLACK tipped syringes. It was a bunch of crap. My son and I have been flying every weekend for 12 years now aside from rain. The only syringes we owned either have black rubber tips or black rubber o-rings. Norvel claimed it would form white taters on the plugs. I see this same stuff on Cox plugs and I use a squeezie Sullivan bulb on those. As for adding Armor All. I've used it in all of my fuels for the same period of time and no damage either. It only requires one squirt. Ken