Mr Cox

Jon Valentine makes Turbo-plug heads for the Norvel .074, search for user name "hyper-speed" or something similar.

Mr Cox

The user name on ebay should be: cox_hyper_speed

But he's not listing anything at the moment.

Halvey

I found Jon Valentines email and sent one off, but to no avail as of yet.

forsakenrider

Is there any chance that a bigmig could run on no nitro ruel? like 20-80? (castor-methanol).

Has anyone tried, or do I need to?

rcguy59

My Feedback: (8)

Remove all but one of the head shims and give it a shot. Power isn't likely to be impressive, but it should run fine. The needle is apt to be quite sensitive, though, so use caution.

AndyW

My Feedback: (1)

You may have throttling issues. Already, without a means to adjust the mixture at idle, the small Norvels fall short at idle and acceleration. WITH nitro, adding shims or deleting could assist in better throttling. This may still hold with no nitro but may become more critical. Standard thickness shims may be too crude to affect the finer tuning needed. Put in an adjustable airbleed and much can be accomplished.

Mr Cox

I often run-in of engines on 80-20 fuel, they do run but the handling (cold weather starts and needle sensitivity etc.) is better on about 10%nitro.

Strykaas

What is the ideal nitro % for the .07 norvel ?

forsakenrider

I wont be running a throttle so that should be no problem [>:] so what about the plug? I have both the nelson regular and nelson hot. should I run the hot plug?

rcguy59

My Feedback: (8)

Mine run fine on 10% but they LOVE 30% heli fuel.

AndyW

My Feedback: (1)

I've run as much as 40% and the .074 just loves it. My Tsunami just comes alive. It turned out a tad heavy but I hope to shave off 3 or 4 ounces this winter.

Halvey

Broke in the 074 using a Mecoa standard plug adapter, 1 head shim, McCoy MC-59, Sig Champ fuel and a APC 7x3. Kinda amazing, it fired right up as soon I touched the starter to it, never had a engine do that. Ran about 20 oz thru it and was thinking I had a dog, only would rev to about 10,5. Then about the 22 oz mark, it revved. 15,5 and still some left with the needle and plenty of smoke out the pipe. Didn't want to get to greedy just yet so I left the needle as it. Idled right down to a stable 3800 each time. Both high and low numbers flyable. Checked the plug coils after I was done and all looked perfect.

I think it still has even more performance left, using a turbo plug,,,, and I have cards and cards of those.

Tore it down and went thru it before break-in flushing out any left over machining deposits with CRC QD electrical cleaner (you should have seen the grey in the jar). Resealed the carb base and carb sinch screws with Racers Choice carb sealant, really good stuff, been using it for years It flows down into the nooks and crannies and holds tight. I use it on all my motors for sealing out those pesky tuning air leaks. Also used it to locktite the muffler screws and seal the exposed ends of those. It's now called Lucky 7 sealant, but it's still the same formula. http://tkocompetitiondev.com/product...roducts_id=378 A little dab of Associated green grease on the upper needle threads and a short slice of fuel tubing to seal that area up. ( I sliced the tubing length for 2.5 turns out)

I'll be in contact with you Andy.

rcguy59

My Feedback: (8)

I tried a Mecoa plug adapter in an 074 and lost over 1500 rpm. The engine ran OK, just lost a bunch of power. I'd love to try a turbo plug but I haven't been able to find the proper head insert and I'm not set up to make my own. If anyone knows of someone who actually has them for sale, please let me know. Thanks.

Mr Cox

Standard plugs are just wasting power on the small engines. If you match the plug length to the head, seal the threads and trim the combustion ratio (often too low) you can almost get good power out of them, but it is a lot of work and fiddling.

Turbo plugs on the other hand can give you a combustion shape that is very similar to what you have with the original glow heads. I have a Turbo plug head for the .074 but I prefer the stock glow insert over it, they are just so easy to use. If the low end isn't right then it is not a problem of the plug but the carb that needs an adjustable low end. The .074 should at least make around 17000rpm on an APC 7x3 and 10%nitro, 15500 will put in the same league as the TT07GP...

The stock heads are also readily available from nvengines.com, so there is really no reason to mess with something else.

I prefer the APC 6.3x4 prop (gives you 17000+ rpm), it is a nice match to the engine and you get a little more pitch compared to the 7x3. Here is a short video of a fully cowled and inverted .074, running 10%nitro, 20% all castor and the 6.3x4 prop. I'm sorry for the low quality of the video but the plane and engine combination is simply a blast to me. On the first take-off the engine had cold down while I was messing with the camera so it misses a little, and I never used full throttle either;

[youtube]http://www.youtube.com/watch?v=trSCx-6zlAo&feature=mfu_in_order&list=UL[/youtube]

AndyW

My Feedback: (1)

Boy that brings back memories. Anyone remember the Midwest foam Chipmunk? Great flier but because of the high density, full airfoil, foam wing, it turned out a bit heavy. The fuse and tail were very light so I built up a wing with 1/32" ribs spaced 1/2" apart, no spar and fully sheeted with choice, medium, 1/32" balsa. I used Micafilm painted with Perfect Paint, a urethane based finish. Power was a Fox .19 and then a Veco .19.

Over a span of ten years I built three, the only plane I've ever built more than one of. I'd do a fourth if I could find another kit.

I also have a Fox .74 powered, Jess Kreiser Chipmunk and I've test flown a Chipmunk ARF. All flew the same, and all were a pleasure to fly.

For general RC work, the stock plugs are about as good as you can get. The turbo article was done at a time when you couldn't get Norvel plugs anymore. Thank god that's changed. Thank you Alex.

But for non RC as in free-flight, rat race, combat, getting a few extra hundred RPM can give you a win, all things being equal. And your choices in a turbo are quite broad with brand, heat range etc.

Variety is what makes the world go round,,, and choice. Neat.

DeviousDave

I've had the chance to put a fair bit of time on an .074 in the last year. It's been a real winner for me even though it hasn't "woken up" like some here say theirs do when the piston/liner fit wears enough. I get 16,500 on a 6.3-4 and it's nearly vertical on a heavy built JM Glaskraft Penetrator. I love the performance, it moves out smartly and the idle just won't quit. Transition seems ok, but I tend to fly like the throttle is an on/off switch.

At SMALL a lot of guys were getting a kick out of me landing with the engine still running-it just has a music wire skid to belly land on-the idle is strong enough to mow grass for a few feet and still be running when the plane comes to a stop. I can't even get it to quit in spins with the idle set way down from what I land it with.

I'm blessed to have many good engines, the .074 is still a standout.

AndyW

My Feedback: (1)

"At SMALL a lot of guys were getting a kick out of me landing with the engine still running-it just has a music wire skid to belly land on-the idle is strong enough to mow grass for a few feet and still be running when the plane comes to a stop. I can't even get it to quit in spins with the idle set way down from what I land it with."

You have got to be kidding. Aaaaaargh !!!!!!!!!!!

RknRusty

Mercy, that was quite a trip through time. I just got my first Norvel, a Big Mig Revlite .061. It's new and tight and I think it was one from the old stock before NV Engines came back to life. I spent the last couple of days reading this thread while, at the same time trying to finger flip the new baby to life with frustrating results. After reading everything here, I believe I did it all right and finally got it running. It took 5 shims and a Babe Bee head to finally get it going and I ran about 4 ounces of 20% castor, 23% nitro through it. I had a well balanced Cox 5x3 prop and it only peaked at 17.5K, but I bet it will spin on up to where it should run when I run it with the proper head and only a couple of shims. It's on hold for a few days for minor medical reasons, but it's all set and waiting for me.

After perusing this thread, I have one question about something that bothers me. When I took it apart to clean and inspect it before trying to crank it, I noticed the wrist-pin floats. Well, it moves if I press on it with a toothpick, but I don't think I saw it come out past the piston skirt, and I certainly didn't try to press it that far. I posted a question on the NVEngines forum(at the time I thought this was one of the new NVs, now I don't). The answers said, "Don't worry about it, it won't come out." So I put it back together and mounted it to the test bench and ran it.

Since then, I read a couple of posts here and began to worry about it. I looked today and there were no scratches on the cylinder wall, so I haven't screwed it up yet. I'm wondering if a properly installed pin will move from side to side if you press on it, but just won't come far enough out to damage anything. And if I do have a problem, I need to do what AndyW describes in the following quote. I can get some 1/8" music wire, but I'm not picturing exactly what Andy is doing. Andy, the part I am not clear on is where you say,"Apply the wire to the edge of the piston hole, roll it forward a bit and whack it with a small hammer." Can someone help me out on explaining, maybe a picture or something, before I commence to whacking on my new piston? Andy, are you out there?

This might be my first post here. I recognize a few names from RCG where I usually head for help... no offense, it's just where I landed when I got serious again and started back into my old 1/2A control line hobby. Anyway, any advice would be greatly appreciated. Thanks,
Rusty

Halvey

Hey Rusty, PV Pilot here. I believe that means to lay the wire around the EDGE of the wrist pin hole right next to the pin. then whack the wire with a hammer to create a peen on the edge of the hole, so the pin cant walk out and scuff the liner, basically stakeing the pin hole. Maybe curling that wire to meet the circumference of the hole. Maybe I'm crazy, but I THINK that's how it reads.

RknRusty

Hey, PV. I'll have to get used to "Halvey."
There is a dimple on either side, and I interpret the instructions as laying the 1/8" wire straight across the dimples and hole and whapping it to further distort the hole's opening so the round pin can't pass through it. That's a pretty fat piece of wire.

I still need to take it back apart and press the pin to see if it really is able to protrude. As soon as the flight surgeon clears me, I'll open it up and take another look. That may be in the next couple of days. She'll buss my ax if she catches me abusing my right hand too soon. Meanwhile, I just want to know what to do if it does need fixing.

Here's a picture as I remember what it looked like:

Thanks,
Rusty

Halvey

Ya, take your time healing Rusty. It will still be there waiting once you get some heal time. Looks like a pretty easy deal stakeing that pin in, not rocket science by no means, but good judgment must be used obviously. You just don't want to drive the wrist pin thru and remove the stake on the other side,,or your back to square one. ( I think you mentioned that the pin would only slide out one side)

sirzepp

My Feedback: (1)

I have a new .074 from nvengines.com. Runs great. I've installed it in a Kadetito and so far it flies perfectly. I haven't really tried to spin it up too far as I didn't really need the power and I wanted to use a standard plug, but it's got ALOT of power for the airframe. I currently do most of the flight at 1/2 throttle.

First question: Am I wrong not trying to eek every last RPM out of it? Right now it spins around 12k to 12.5k with a std plug, one shim, 20% fuel (with 50/50 synth castor at 20%), at 4500' above sea level. I am going to prop it down a bit...all I had was a 7x4 after I busted my two 7x3 APCs being dumb. Going back to the 7x3 as soon as I get one. It doesn't go lean, actually increases and sustains RPM when held nose up for extended period of time. I'm happy with the performance at the top end, but I don't want to screw the motor up. It's still REALLY tight at TDC...as in...I can't hand flip it and have been (carefully) using an electric starter.

Second question: Idle is around 5k rpm. I see no adjustment persay on the carb (there's a small eccentric screw that seems to rub against the throttle arm and act as some sort of stop, I can raise a lower idle speed a bit with this, but not enough to see a lower idle). I wasn't expecting a 'put-put' idle, and 5k is enough to slow down for landing on grass, but it rolls away on pavement and even on grass I have to fly it on as opposed to a nice full-stall landing.

I have read about some guys adding an airbleed to adjust idle, and also someone who added a second needle, but I'd rather keep it simple and I think there might be something I'm missing here. This is my first norvel, and I have never had a 1/2A engine with a throttle (used to fly Tee Dee .049s 20 years ago).

Andrew

The idle adjustment screw can be removed - it's a blind hole and it's only function is to serve as an idle stop, so removing it will allow the carb to close more fully. Use your throttle servo trim (or adjustable end-points if your TX supports it) to set the low end. You may be able to realize a few RPM lower, but these engines tend to turn more than their larger brothers.

sirzepp

My Feedback: (1)

That is perfect! I was wondering if I could remove that screw, but I didn't want to break it!

Thanks so much.

FWIW, I did the full break-in procedure as outlined earlier in this thread.

I am really impressed with this engine and this plane. I am hooked...looking for my next 1/2A project now.

Mr Cox

To me they should at least spin above 16500rpm to be happy. The APC 6.3x4 is a nice match and will give you +17000rpm.