Is Norvel .074 OK to Buy (rod?)
 

But in the end it is still a great runing little engine. I know my 074 will out due my os fp10 any day and is about half the weight. Not to mention will run twice as long on the same amount of fuel!!!

Is Norvel .074 OK to Buy (rod?)
 

Hi guys, my job changed, so I don't get any computer time any more!!!

LOVED the Arkansas Palm Pilot thing. Thanks Dickey.

Hay powerglide.... I think you seem a bit hot under the chin. These engines have a CERAMIC liner. NOT ABC, NOT like any other engine you have ever run!!! The ceramic is SUPER HARD!!! It takes a lot to change the fit of the ceramic liner. The tighter the engine when new, the better it will be in the long run.

My first 2 .074's were so tight that they WOULD NOT go past TDC even with the heads off. After talking to Norvel, I oiled the cylider with 10W30, flipped the prop by hand for about 2 minutes, then spun it with a starter for about a minute. ALL WITH THE HEAD OFF.

After that, it would turn over by hand, but not run for more than a minute. Took the head off and did it all again. Now both engines are SUPER. Good on fuel, strong, fast, easy to start, etc. If you don't do something to lube the piston/cylinder liner before you start, the engine will give you fits.

I recomend the Norvel line of engines. When broken in correctly, they are hard to beat for longevity and performance. I can tune a Norvel and but DICKEYBIRD is the man for Cox.

Is Norvel .074 OK to Buy (rod?)
 

Man, am I glad my wallet is empty after the Christmas binge! All this .074 power/weight ratio talk, 7x3 props and anodized liner stuff, good throttling AND THEN Andy W. praising them so eloquently. I could ALMOST see one on the front of the "Cornbread" giving it faster climbing inverted flat spins and even better hover power. Whew! I saw it there just for a second then it quickly faded back into a fresh TD with more compression and an old style TD cylinder & piston with a Galbreath/Nelson head.

I gotta get home to the workshop and fondle some Cox parts! ;)

ps: Good to see yer back with us 2fast, I was worried when the Ark. Palm Pilot wisecrack didn't get an immediate response from you! :D

Is Norvel .074 OK to Buy (rod?)
 

Yeah, I love Cox too. Got me maybe a dozen or more, mostly .049s. Plus several .020s and .010s with custom made exhaust throttles. Despite the design being what, 50 years old or older, they still have a very attractive, modern look.

If I could only get the right size die though, ( I have a tap) I'd try and make an ABC, or AAN version (or maybe Revlite). Just to see what's what and maybe eliminate that troublesome (for me anyway) ball socket rod.

In regards to performance, power to weight and the like. Well, yes this could mean go like stink, hover etc. But it could also mean a lighter, better flying airplane. There's a compounding effect. Airframe a little robust, mini instead of micro servos, ditto receiver, a 250 pack 'stead of a 150 and now you need a bigger engine to get the plane to fly faster just to stay in the air. So, save weight on the airframe, servos, Rx, pack and FINALLY on the engine. The total result, a lighter, better flying airplane.

THEN you punch the throttle and go vertical. Well, not if it's a Nieuport but you know what I mean.

Currently working on a diesel utilizing a Norvel .049 piston and cylinder but with their .074 crank. This will give about an .06, but with a real long stroke just like diesels of yesteryear. It's been my limited experience that long stroke diesels start more easily, handle better and like to swing bigger props. Such an engine, as a diesel, would swing a big, like 8 X 4 prop, with lots of torque, at low rpm and might just be ideal for things like,,, a Nieuport? We'll see. Test runs in the spring.

.07
 

Take a look at the Thunder Tiger .07. It is built like the larger size engines, runs well, looks good and should be reliable with out an extended break-in time. I had two Norvels and gave up on them and went to the TT.

Harvard

074
 

hi, never had a rod problem with my 074's, have had 3, still have one (sold other 2 with planes they were on). always took head off, oiled them, then spun by hand or with starter until they loosened up a little. saw a guy bend one on a lite machine (061) because he choked it too much. it started ok, then started clacking as the piston skirt hammered on the crank since the rod was now shorter! I took it apart, and it was bent beyond repair so I got him a new piston/cyl. set and no further problems. I've only had 2 problems myself with any of the norvels; the wrist pin hole elongated on my first one about 3 years ago, which Ed Stevens replaced free. And I had a prop stud shear in mid air at full throttle on one of the first plain bearing 25's. it went up to a burbling super high rpm before I throttled it back, I thought it was toast! but now it is one of my hottest engines!! Do you think the high rpm's seated the nickel/ceramic better? How's that for a break-in? -wildfred-
here it is on my ferroplane; better than 110 m.p.h!

Is Norvel .074 OK to Buy (rod?)
 

Wild Fred,

You have a point about bent rod first, clacking piston next. Chicken or the egg, I guess. Still, the rod is too thin methinks,,, at least the current crop of rods with the round shank. I've had one or two of these bend on me. Never had that happen when the rods had a rectangular profile. Matter of fact, if you've got any like that, even if the piston or rod is toast, I'd be interested. What I do is install brass bushings.

Your .25 experience confirms my belief that the Revlite system is tougher than any ever devised. I still think the Norvel rods are a tad too light.



Harvard,

What have you done with your Norvels? Are they .061 or 074s?

round rods
 

I had a similar situation with the r/c trucks; the duratrax engines had a round rod, most others had a square one. Had a few guys come in with broken rods on dtx, but never a square rod engine. I know that the lighter the rod the less vibration, etc., but aircraft engines need strength, too; at least mine, which have a tough life! My favorite is the fox b.b. 15, which I have on my 1/2 a giles; vibrates more and about 3/4 oz. heavier than my norvel 15, but more power and very rugged. also has square rod! They don't like low oil fuels, but I have run sig 20% oil 1/2 castor fuel in everything for the last 2 years and no engine problems since I started running that (15% nitro, by the way). Speaking of rods, used to run t.d. 051's before norvels came along and had a HOT td 09 for a while. I only broke 1 rod on those; had a radio failure and it came down through a tree; broke the rod, but I never found the top half... or the piston and cylinder, either... :D

Is Norvel .074 OK to Buy (rod?)
 

Well I just bought a new Norvel Big Mig .074 RC.
In the store I flipped it over with a prop on it and thought, "Wow! this is high compression!"
I got it home and started to check it out. I took the head off and I took the back case cover off. This is when I found what I think to be a problem. As I turned the engine over I still felt the same "high compression" that I felt in the store. I took the carb off to make sure that it was not catching on the crank. It wasn't the carb. When the piston comes within an 1/8" to the top it starts to tighten at the top. It gets very tight. Everything seems to be smooth on the rotation untill the top. I really don't think this is normal because it just seems like it is too tight for the engine to run.

In case this is not normal, I don't want to chance running it. My hobby shop is close till monday so I can't find out about it till then.

ZZ


So anyway... :o
As I posted this, I then realized I did read any of the above.
Reading is good...
I found alot of information that will be very helpful in my new life with a Norvel .074. The only thing I didn't find was what size prop is best for break-in.

I am going to run this engine on a 24" Beech Staggerwing biplane. I want a slower flying aircraft. Anybody recommend what would be a good pitch on a 6 inch prop or should I be sticking with a 7"

ZZ

Is Norvel .074 OK to Buy (rod?)
 

ummmm zoom I know its a guy thing but, read the instructions, its supposed to be tight like that, fill cylinder with OIL, let it soak, flip it over, put the starter motor to it for a minute or 2 with the head off, fuel it up, and fire it up, I run a motor for about 2 minutes, let it cool for 10 minutes (heat up cool down helps breakin)and repeat for about 1 oz of fuel, then run another 2 or 3 oz through it, and it should be ready/...Rog

prop
 

I have had good luck with a master airscrew 7-3, plenty thrust, not too fast. for speed I use 6.3x4 apc .15 combat prop.