Norvel .074s on Ebay

Understand something about the .074. It's caught in between prop sizes which makes your choices very limited. In addition, the plug is special to that particular engine. The engine is a very well made and powerful small engine not to be compared to .074's of yesteryear by no means. For those trying to use it for 1/2A control line size planes it's way overpowered which makes it difficult to slow it down. I used one on a Brodak 1/2A Pathfinder and the end result was not so favorable due to it flying too fast to stunt even going out on 50+ feet of line. It can fly 250 squares with ease which is what most older designed .15 size airplanes are.  Using 4 pitch size props with this engine will not make it very happy as it wants to turn and that much pitch loads it down which is typical of most Norvel's. However, Master Airscrew makes a 6x3.5 which due to the thin blade area makes that prop work well for most applications. Using 7" pitch props is not out of the question but finding them with light pitch is a must and thin blade areas also assists. The old Plastikote Tornado props is what I ended up using on the Pathfinder which was a 7x2. 7x3's will work and are much easier to obtain but experimenting with different brands yield the best results.

       The shaft on the Norvel is also larger than the holes for 1/2A props therefore you must ream out the props for the .074 making them exclusive for that engine. A fellow club member recently built the RSM Pinto and had the .074 slated for the powerplant. I finally talked him out of that choice based on my experiences as he's intending to fly the Pinto competitively in stunt. He settled on a G-mark .061 which surprisingly flies with a very timid run which seems to be working but I wouldn't of gone that route as I'm a fan of the .061 Norvel's. Ken

I certainly don't disagree with Ken's analysis, particularly WRT to control line.  However, the engine throttles very well and gives sufficient power to fly RC planes that were originally classified as 1/2A, but were literally too large for optimum performance.  Three examples that fit this catagory are the Sniper (38") by Hans Hochradel, Owen Kampen's excellent Pacer (42") and the ACE Mach None (40") designed by Ken Holden.  With today's equipment and careful building, these become outstanding performers with the .074 and can be flown as full house if desired.

Props can be, as noted, more of a problem.  An almost ideal RC prop was an APC 7x3, but they are really becoming difficult to find.  Master Airscrew has a 7x3, but it will not turn up to the APC numbers.  It can be cut down to 6.75 if you desire, but for some of the larger aircraft, the bigger prop does give a bit more pulling power.  The prop screw on the .074 is a 4mm.

Plugs for the .074 are available through K&B Manufacturing.  There is also an adapter button that uses a standard plug, but it's not generally recommended.  

The engines on eBay are obviously NOS, but at $50 with free shipping, I bit the bullet and added another to my stock.

andrew

Dangit!!!

One of these just jumped in my PayPal account! The LAST thing I need is another engine....

The Running Out of Room Mark

The heli versions are cheap. I picked up a couple. Might make a good upgrade for a Cox GTP Nissan.

Jason_WI wrote:The heli versions are cheap. I picked up a couple. Might make a good upgrade for a Cox GTP Nissan.

I WAS going to pick up the heli version, but SOMEone bought the last ones before I could put in my order....

batjac wrote:

Jason_WI wrote:The heli versions are cheap. I picked up a couple. Might make a good upgrade for a Cox GTP Nissan.

I WAS going to pick up the heli version, but SOMEone bought the last ones before I could put in my order....

Wasn't me! I swear... As stated above there seem to be plenty left at $24.

Jason_WI wrote:

batjac wrote:

Jason_WI wrote:The heli versions are cheap. I picked up a couple. Might make a good upgrade for a Cox GTP Nissan.

I WAS going to pick up the heli version, but SOMEone bought the last ones before I could put in my order....

Wasn't me! I swear...  As stated above there seem to be plenty left at $24.

Strange. I tried twice and the heli engines did not show up. But clicking the above links does show them. I just ordered two of the heli engines. Now, what I'm going to do with three .074 engines, I don't know. Maybe a C/L Fokker Tri-motor.

Ooh! Ooh! I know, a C/L Trislander!!!

The 54 Mark

Ha, flew a Britten-Norman Trislander from
Boston to Hyannis a while back. Strange
plane. The harmonics of the engines were
a pretty weird soundtrack.

Bob

Ken Cook wrote:Understand something about the .074. It's caught in between prop sizes which makes your choices very limited. In addition, the plug is special to that particular engine.

It is strange how the great strengths of this engine can ever be thought of as something negative...
I guess you are correct when it comes to CL use in 1/2A planes, but for RC use it is a true gem in every possible way. It can handle the prop sizes that we always wanted to use on .049, but never can. Plus it throttles well, so overpowering is never a problem, you just throttle down to what suites the plane. Should be possible to use a reduced, fixed, throttle setting in CL applications too I would think?

The engine runs really well on the APC 6.3x4 prop, it will do around 17000rpm and there is no problem with reaming the prop. The prop bolt is easily replaced with a prop stud, and there are some really nice Al spinner from MP Jet that are a direct fit.

Here is an little movie clip that shows what the engine can do (I hope) in a CG super chipmunk (ARF), the conversion to glow also makes is lighter than it would be on the originally intended electric power;

(at around 1:10 I'm fiddling with the idle setting on the radio...)

I took a quick look to see what is available on ebay, and found this;

ebay link

"You are bidding on an RC item. From a closed Hobby Shop. Rare and Vintage! Please google the part number or visit the manufacturers website for exact specs. This item is brand new and looks perfect!"

Check out that brand new perfect vintage look;

Kris, I don't feel my contribution to the post was negative in any way. I was simply expressing some concerns. Seeing that most of the visitors here on the forum are dedicated to the smaller engines and fly the smaller planes I was simply stating my experiences with this engine. It wasn't meant to come off as negative. However I have seen this engine surface many times in the past few months on here. It's not an engine that tames down easily for small control line use. This is why I also mentioned the size which 250 squares is even at the bottom end for the capability of what the .074 can fly. I have no experience with r/c because I've never flown it. I'm a Norvelholic and I enjoy every engine I own from them. As far as the APC 6.3x 4, it was a .15 sized combat prop developed for .15 size engines. It also has a substantial blade width over a GF series Master Airscrew. Not saying it doesn't work because I know it absolutely does, I was merely making a point that this engine does have a limited choice of props to use.

So this would be perfect for a Ringmaster Jr?

Phil

Surfer_kris wrote:I took a quick look to see what is available on ebay, and found this;

ebay link

"You are bidding on an RC item. From a closed Hobby Shop.  Rare and Vintage! Please google the part number or visit the manufacturers website for exact specs. This item is brand new and looks perfect!"

Check out that brand new perfect vintage look;

It's no wonder the LHS closed! HA, if this is "perfect brand new" they forgot to mention it was "brand new" epoxy to "perfect" The necessary repairs to the Venturi!

[quote="1/2A Nut"]You can still buy the Heli version. It has a upgraded bronze sleeve unlike the stock
version that has a thin steel sleeve. It does make more power than the stock engine.

http://www.ebay.com/itm/Norvel-Vmax7-LMH-074-Revlite-Sport-Helicopter-Engine-RARE-/272491930604?hash=item3f71c8e3ec:g:-P4AAOSwZQRYWNh6



 Published on Jan 29, 2017

Norvel Vmax7 Heli Engine 20,510 rpm / MA 5.5x4.5
Litemachines final upgraded engine for their Heli.
New old stock inspected and signed, dated 11/04/02
20,510 best peak / 17.8oz thrust /.255hp / 190.23w / 87.3 mph
25% nitro / 20% oil / Standard plug and head 5 ports Revlite






Brad, can you provide details on "lightmachines" upgrades?  Looks to me the ones offered on eBay will require:
New prop driver, prop washer & prop screw (spinner)
Turned down head or shorter head?
RC carb and Venturi to replace Cl/heli needle valve.
Are these parts available or did you make them yourself?  Thanks!

I haven't messed with a .074, but I did make two .061 heli engines airplane ready. I did score the face of the prop driver to grip the prop. I just used a standard Norvel spinner and drive screw. For the fins, I cut the tall head down to only three fins. I took a small hobby hacksaw and cut all but four fins off. Then I cut and filed off the top (fourth fin) and cut grooves across the remaining material for a wrench to get a grip on. Then I took a file and made the head fins match the profile of the fins on the cylinder.

An interesting thing about the throttle. For the .061 heli muffler, the throttle moves a rod left to right across the muffler exit to block off the exhaust and throttle the engine. Too much of a hassle to try to rig up a right angle bellcrank to throttle the engine for airplane use. But, I discovered that you can pull the rod out from the side and it will slide straight in from the back. So, using the wire to push the rod in from the back to throttle the exhaust flow out the side works almost as well as the original method. I don't know if the .074 muffler holes are the same. Maybe Nut can tell us if it will work both ways.

The Backed Up Mark

Nicely done!

andrew