darthdrk

Ok, heres the deal, ive been through two piston connecting rods on my Vmax7 engine even after following the break in procedure. They seem to have broke on about the fourth or fifth tank of fuel. Ive heard from others having the same problem. was wondering if anyone else is having or has had the same problem and what was their remedy. Ive since gotten the engine replaced and have not fired up the new one yet. Anybody out there with any answers ? Also heard that there was a bad lot of engines that went out and that could be part of the problem, I just got a couple of those engines. Each time the connecting rod broke, I sent the engine in and they sent me a new engine back. Im on my third engine. Looking for suggestions and help, dont want to go through this again.

Mini Boy

Hi Darth!

1BMF in this LMH Helicopter forum sounds like he has a heating/siezing problem with his V-Maxx-7.

There was a thread I was reading last week where someone else had replaced a connecting rod or two, but I can't find the thread ... maybe Spiro knows where it is.

Happy Choptering,

Russ

Spiro

I am pretty sure Darth has been in on nearly all of the engine and rod discussions. Here are a few of the recent ones in case anyone is interested:

http://www.rcuniverse.com/showthread...&highlight=rod

http://www.rcuniverse.com/showthread...&highlight=rod

http://www.rcuniverse.com/showthread...&highlight=rod

http://www.rcuniverse.com/showthread...=things+to+try

I have also gone through two con rods, though both in a Big Mig 0.61 and not the Vmax6. With the first con rod it broke during the break in period, perhaps after 30 minutes of running. The second con rod broke after the break in, perhaps after 3 flights. I have no suggestion as to how to avoid this in the future. My rod failures have (in the second case, and early in the first) occurred after very careful and very lengthy break in periods following Norvel's specific instructions. Also fuel, nitro, and all rpm were kept carefully at Norvel’s recommendations.

For what it is worth,
Spiroo

flyinrog

My Feedback: (1)

you know guys, I'm really not liking this thread now I just about finished my ACE whizard which I bought a Norvel .074 and I just switched out my .061 to the .074 on my LMH and , I aint gettin a warm fuzzzy feeling outa ya'll........?

Mini Boy

Geeez Rog:

Did you ever try one of those electric motors ... you plug in the battery (that you can recharge a thousand times), turn on the little switch, push the throttle stick forward, and off you go!

It's really kinda simple. Clean, too. Quiet, too.

Even I can do it!

Happy flying,

Russ

Spiro

If it is any consolation it seems as though people go through rods in both engines.

I have not flown it myself, but from what I have read the Vmax7 sounds like a much better performing engine. I would have one right now if it weren’t for the $90 upgrade cost. Perhaps when my Vmax6 gets too tired to haul the works around…

Spiro

flyinrog

My Feedback: (1)

yeah miniboy, I got electric park flyers but not heli's and cant spend the $$ to buy another one, and havent really heard great results from folks that have switched over...ie it is not cost effective to change to electric either..I only changed to the .074 because it came with the package that I got in the classifieds...Rog

Mini Boy

Hi Rog!

I hear ya barkin, big dawg!

I wasn't aware that you were running a machine that had come with glo power ... I was only kidding around anyway ... ask Spiro, he knows.

As I said to him, the glow vs. electric debate will go on forever, even after all liquid fuels are banned from use in the U.S.A. ... BUT, flying SOMETHING is way better than not flying at all!

You fellas are really doing a GREAT job with those glow engines, and you should be proud of of your accomplishments! I really enjoy following these threads to track your progress in the never-ending quest for perfection. Keep up the excellent work!

Happy flying,

Russ

darthdrk

About the glow powered LMH's, They are lighter than the Electrics. I hear the electrics refered to as a flying brick. I have just about everything to do an electric conversion and boy is it heavy. I fell out of the sky yesterday from about 15 feet above ground. I was pretty much in a hover at the time. Wasnt monitoring my fuel level. Well, I ran out :stupid: . I was really getting into sporting the AH-6 Little bird heli fuselage. I was having a TC flashback(Its a Magnum P.I.thing)I completely forgot about gas. Just some very minor damage to the fuselage. Mainly just flattened out my landing gear. Squeezed my gear back to where it suppose to be and put some more fuel in and off I went again. . If that was a Corona, im sure the battery would have dislodged and would have had a boom strike. I didnt even have a boom strike. Then again Im using my new crutch design which gives me a higher rotor to tailboom clearance.

fastlash

My Feedback: (7)

There is a problem with the early 074 rods but the replacements should be ok, I take my engine apart and i put the piston in a drill press jig and with 2000 grit emery and light oil, I work the very top .020 ths down until I get a nice fit to the sleeve then I clean and oil every thing down mount and run it with 20% nitro 20% castro fuel with a prop, I lean it down right away so the engine gets hot and the sleeve expands reducing the load on the rod, run it cold( to rich ) and you will ruin the rod, because the fit of the piston will be to tight during break ln. I also use at least 5 head shims during all this, I havn't broken a rod yet

darthdrk

Mabey I should send you my Vmax 7 and let you break it in for me. :-)

fastlash

My Feedback: (7)

You can do that but you have to send me one of your bodies as payment,takes quit a bit of time, by the way Iam in Eatonville about 40 minutes from you!!!

10karer

My Feedback: (2)

Hey Guys

Well I'm not happy, just got another new 7 and within 10 min have broken the con rod. This engine was broken in by light machines and, I change fuel and it still broke I don't Know what to do at this point.

darthdrk

I hear ya 10Karer, Im on my third engine. The first two Con rods broke within three tanks of gas. I recieved A replacement Vmax 7 engine(a third one) from litemachines a couple of weeks ago. I still have yet to break it in. Im getting on edge about even firing it up. To me without a doubt, there is a problem with these engines. We all cant be doing something that bad for us to be breaking rods like they are going out of style. I dont fault litemachines I think its a norvel problem. It would be nice if Litemachines decided to find another manufacturer to make engines for their product. There are some problems I can work around but the fact is, if your engine is down, you just aint gonna get off the ground. We need some relief. Ive had filaments burn out completely in my vmax6 several times and yet I have not broke a rod on one of them at all, yet alone because pieces of the filament caused my engine to jam. The power of the Vmax7 on the litemachine is awesome but whats the fun if you can only fly about two tanks, if you make it to two, before you have to replace the engine. I hate to see that the Vmax7 is beginning to get the rep as a rod throwing lemon engine. Boy, I sure did hoot a hollar about its power . But kinda hard to hoot and hollar anymore when you fear that dreaded sound of the engine quitting on you in mid flight because your rod died.

10karer

My Feedback: (2)

Your right Darth

it is a very frustrating feeling to hear that dreaded clink and watch the heli fall to the ground after a violent spin

Mini Boy

HHhhmmmmmmmm ......Whizzzz ... WHrrrrr .... Whoppppp ....Whhopppp ..... Whoppppppp ...Whopppppp ... Whopppppp ..... Whopppppp!

Hacker ..... Flashlite batteries ... HHmmmmmmm Whizzzzzz .... Whirrrrr .... Whopppppp ...Whopppppp .... Whopppppp .... Whopppppp!

No troubles!

Really neat!


Do you guys ever even HEAR that cool rotor beat???

Remember, as Spiro knows, ... this glow/battery thing is all in FUN!!

Happy Choptering,

No frustration,

Russ

darthdrk

well, here goes nothing. Im gonna break in my Brand new Vmax7 today. Im gonna take it slow and easy. Wish me luck guys. It I break the rod on this one (I dont know what im gonna do) Probably ask for my money back. Im gonna try some of the litemachines Litelube as Paul Arlton suggested on their bbs. Im gonna hand turn it for a while then Im gonna use my starter for a while. I gonna start with the head off . After that Do it all over again with the head on. after that Im gonna mount it in my heli and then run some fuel in it really rich(got five washers under the head, 15% nitro w/18% castor) Run it for a while then lean it out . Richen it out then lean it up . Im gonna follw the breakin to the TEE. If I make it past three tanks without breakin a rod I still dont think Ill be out of the woods. Well, here goes............ Ill post the results later.

fastlash

My Feedback: (7)

Run it rich and you can kiss the rod good buy!!!The sleeve will not expand enough to allow the engine to run loose,

darthdrk

Ok, heres where Im at. Im up to three tanks of fuel through my Vmax7. Shes a purrin like a kitten. Nice steady tone. Ive actually got a little flight in but its really windy right now. So far so good.
The smile is returning to my face. Mabey later when the winds die down, Ill take it back out for some more run ups. I got wacked in the forearms by the blades and got two swollen welts and they kinda hurt too. Good thing I had on long sleeves or Id be bleeding.

fastlash

My Feedback: (7)

Darth pull the head now and check and see how much pinch is left then check your rod slop by bring the piston up to but not all the way to TDC and rock the crank back and forth, if its got a lot then the rod has all ready egg shaped the big end jounal. hope this one lasts for you,

darthdrk

Ill check it tomorrow Fast, Just got back in from another tank and a half of running and flying. Started raining. Ok, up to five and a half tanks of fuel, so, Ill say about 11 oz of fuel. So far so good, I hope. I also put my Cobra body back on .

DrMyke

My Feedback: (-1)

hope that engine works for ya. Hate to hear of ya breaking another one.

bear9236

My Feedback: (1)

I have had two .074's and still have one and i also have two .061's one heli and one airplane .
I have had no problems with any of them .
I also have three of Norvel's .25 engine with no problems .
I followed the following procedure on all of them and they all run great.
Take the head off and the screw on back plate out and remove the carb and muffler . Clean all parts in denatured alcohol to remove the residue put on for shipping . Dry parts thourghly and use some high temp silicon sealent used for car engines and seal the bottom of carb, the draw bar that holds the carb on and the back plate. Before sealing the back plate drop a few drops of oil onto the con rod and the crank pin .
Put a few drops of oil into the cylinder and rotate allot while watching TV and it passes pretty quickly . Then put a few more drops in and rotate with an electric starter for a while .
With the airplane engines it is easy to mount a prop where the engine sits horozontal to break in so the con rod in the back gets plenty of lube but with the heli engine the motor sits normally in the verticle position with the rod to the top .
Find a bolt that will fit the crank and get a prop that fits your engine, .061=6x3, .074=7x3, and mount the engine horizontal to a board and break it in per the instructions .
I have done this to all my Norvels and have had no problems with air leaks or rod problems .

Barry

darthdrk

Our problem with the Vmax7 engine is comming from a bad batch of engines that was sent out with a faulty wrist pin. Or at least something like that. (So what has been said)

DrMyke

My Feedback: (-1)

Darth, do you know if there is anyway to tell if it a bad batch engine? i dont see any lot numbers or anything on them ..