Norvel 074 vs Novel 061
 

Hi all, I think I have a big mig .074 that runs great and idlers very good/slow. A friend at the field asked if the Novel .061 runs and idles as good as the .074? I said I don't know. I'll ask the experts here. I think I've heard Norvel made 2 differnt motors the same size. AME and big mig. Jump in and correct me if I'm wrong but I assume it matters when comparing and one is better than the other. My friend doesn't need a hi performance speed motor, but would rather have one that idles good. Any thing to know when buying? Thanks Terry

RE: Norvel 074 vs Novel 061
 

The big mig has 2 extra ports, 2 intake and 3 exhaust so its the more powerful one, but I think they both idle well,,the .074 is by far the nicest of the Norvel small engines.....always start like a light switch, plenty o power just a real nice engine...Rog

RE: Norvel 074 vs Novel 061
 

Norvel made several .061 engines, but basically there were 2 revisions of 2 versions, if you follow.

Norvel made the Big Mig sport engines, with emphasis on easy running and the AME series, with emphasis on raw power. The Big Migs are much easier to run and idle better, in general.

In the beginning there were chromed cylinders with aluminum pistons. These cylinders have small finns cut into the cylinder mount holes, so that the fins are not full round circles, but have 4 flutes in them. These engines also typically have glued in carbs. They work well and are reliable.

Then, they developed what they called "revlite" engines, with ceramic coated cylinders (aluminum oxide, ie hard anodized). These have darker, dull cylinder fins, and the fins are larger than the chrome cylinder examples, fully enclosing the mounting screw holes. The carbs are bolted in. These represent the best of the Norvel engines (IMHO) and are longer lived and perhaps a touch more powerful than the older chrome cylinders.

About idle performance compared to the .074's. Not nearly as good, but still pretty good for 1/2 a once they're broken in and you've figured their nuances out. I'm flying a .061 on a Herr Aquastar flying boat. Running a 6x2 on Sig 25%+extra castor, it turns about 21,000 and is idling at about 7,000 rpm. That is slow enough to actually land the plane. Many here will report lower idles, but that's what I could get with the reliability I needed for a flying boat. I don't like recovery boats. I like to taxi back under power.

In about a dozen flights on her so far, no deadsticks.

J

RE: Norvel 074 vs Novel 061
 

The Norvel .074 idles and accelerates exceptionally well despite not having an adjustable airbleed. The .06, however, needs that feature. There were two versions of the .06 (and .049). The AME had three transfer ports and the Big Mig had five. The .074 has five ports as well and the .06 Big Mig with the five ports idles and throttles better than the AME's three port. But it's not perfect. However, if you maintain the same fuel, all the time, you CAN adjust the airbleed with a small three point file. All three engines have an air bleed SLOT that you can open up VERY SLIGHTLY with the file. A tiny bit at a time, you can't go back if you over do it. Well, you can but then it gets REALLY complicated.

Another method of getting a better idle is to adjust the compression. If you find your idle to be rich and if you don't want to start hacking at the throttle, try this. Adding copper gaskets/washers results in the need to close the main needle a bit. This serves to lean out the idle at the same time. Sometimes that's all it takes. But remember, if you change nitro content, you'll have to start all over again. Best fuel for these engines is 25% nitro for power and throttling.