LMH Vmax 7 engine
05-21-2003, 03:37 AM
#26
Senior Member
Thread Starter
Join Date: Dec 2002
Location: Munford, TN
Posts: 1,169
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
There is no way that I can tell, I heard from Litemachines that there was some that went out with this flaw. Im sure its not Litemachines fault. It probably wasnt noticed until people started having the problem.
05-22-2003, 02:53 AM
#27
Senior Member
Thread Starter
Join Date: Dec 2002
Location: Munford, TN
Posts: 1,169
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
Ok, guys, hopefully Im out of danger by now. I put at least about six tanks through the heli today, so, Im up to about 11 1/2 tanks of fuel through the Vmax7 and no "clink" yet. Smile is getting bigger on me mug 
still running five washers under the head with 15% wildcat. So far, so good. 
still running five washers under the head with 15% wildcat. So far, so good.
05-23-2003, 02:22 AM
#30
Member
My Feedback: (2)
Join Date: Jan 2003
Location: Fort Worth, TX
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
Ok Guys
The Offical Word is that during the production of the piston/conrod they "Coin" the sides of the piston, which means they put two indentions in the piston to hold the conrod in place. This is not being done properly at the factory the con rod floats and catches in one of the transfer ports seizing the engine and braking the con rod.
The Offical Word is that during the production of the piston/conrod they "Coin" the sides of the piston, which means they put two indentions in the piston to hold the conrod in place. This is not being done properly at the factory the con rod floats and catches in one of the transfer ports seizing the engine and braking the con rod.
05-23-2003, 04:07 AM
#32
Senior Member
Thread Starter
Join Date: Dec 2002
Location: Munford, TN
Posts: 1,169
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
If the wrist pin catches a port, it stands to reason the rod will break because of the somewhat jam that would occur when the pin get snagged. Ive actually had one engine when pushing the piston head all the way down, there were two grooves created by the wrist pin on the inside of the cylinder wall. On the second engine I dont know why it broke, couldnt see any marks on the cylinder wall, mabey it got caught under the sleeve. So far, Ive been doing ok with the latest engine I ran about four more tanks through it again today, so, that puts me at about fifteen and a half tanks. If it aint broken in yet , Its never going to get broken in. Been flying really good. so far no problems. Getting my big grin back 
05-23-2003, 02:37 PM
#33
Senior Member
My Feedback: (7)
Join Date: Jan 2002
Location: Eatoville, WA
Posts: 679
Likes: 0
Received 0 Likes
on
0 Posts
Rod
Thats 100% right darth only the pin can catch the port and snap a rod, I think Ihave been lucky so far and the STAKED pin has held up in mine, (so far) I think I might check into makeing some teflon wrist pin buttons if the problem crops up in one of mine. glad to see that it is working out for you this time,
06-11-2003, 03:33 PM
#38
Join Date: Apr 2003
Location: Mesa, AZ
Posts: 588
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
Darth,
I believe you have mentioned that you have gone back and forth a couple of times between the Vmax6 and the Vmax7 for various reasons (spare motor swap, testing performance of fuselages with both engines, waiting for replacement Vmax7).
I was wondering if you swapped back and forth on the same crutch. If so, how did you do this? I would like to modify my crutch to accept the Vmax7 but it would be nice to still be able to bolt on the Vmax6.
Any thoughts? Thanks in advance,
Spiro
I believe you have mentioned that you have gone back and forth a couple of times between the Vmax6 and the Vmax7 for various reasons (spare motor swap, testing performance of fuselages with both engines, waiting for replacement Vmax7).
I was wondering if you swapped back and forth on the same crutch. If so, how did you do this? I would like to modify my crutch to accept the Vmax7 but it would be nice to still be able to bolt on the Vmax6.
Any thoughts? Thanks in advance,
Spiro
06-11-2003, 07:33 PM
#41
Join Date: Apr 2003
Location: Mesa, AZ
Posts: 588
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
Darth,
So are you saying that both engines will bolt up to the same crutch and can be swapped back and forth on that same crutch? Or did you bolt a Vmax6 engine to your dedicated Vmax6 crutch and a Vmax7 engine to a second dedicated Vmax7 crutch?
Jeff
So are you saying that both engines will bolt up to the same crutch and can be swapped back and forth on that same crutch? Or did you bolt a Vmax6 engine to your dedicated Vmax6 crutch and a Vmax7 engine to a second dedicated Vmax7 crutch?
Jeff
06-11-2003, 09:52 PM
#42
Senior Member
Thread Starter
Join Date: Dec 2002
Location: Munford, TN
Posts: 1,169
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
Spiro, I did it. I would say the only thing you have to be aware of is that the hole pattern for the V7 is a little wider. So , you will have to take care in centering the V6 engine making sure you have a good maingear and clutch bell pinion mesh. Besides that,
Whoooohooo!!!. Im almost finished with my electric conversion. Im on some down time with my gas setup because i wore out the clutch shoe and clutch bell. Waiting for some parts. Gotta run go ship some heli bodies.
Whoooohooo!!!. Im almost finished with my electric conversion. Im on some down time with my gas setup because i wore out the clutch shoe and clutch bell. Waiting for some parts. Gotta run go ship some heli bodies.
06-19-2003, 12:59 AM
#45
Join Date: Apr 2003
Location: Mesa, AZ
Posts: 588
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
I am in the break in process for my first and only Vmax7. So far I have two tanks through the engine and am simply amazed. After a thorough preparation, I started running the engine as recommended: 15% Norvel fuel, 6 washers, 2 minute rich lean cycles, full throttle with the skids weighted down.
I put my normal two bricks on the skids and opened up the throttle. With the engine running rich it started to shift ominously around and lift off! I had to stop and get heavier bricks. Do you realize the significance of this statement? BRICKS man, I had to get HEAVIER BRICKS. The first set of bricks proved INSUFICIENT! I was awe struck.
Just incase there is any question about what we are talking about here, I have attached some photos. The Vmax7, during break in and running rich, proved too manly for the bricks on the left. The bricks on the right held things under control, but the plastic landing skids were flexing with some serious protest. That is the Vmax6 in the foreground for reference.
Once I had some beefy enough BRICKS for the job, (wow), I fired it back up and put tach under the blades. My ears were not deceiving me, I was getting near 2200 rpm at the head! Manufacturers instructions or not I could not comfortably let the engine run wide open during the break in process at %110 speed. I throttled back for the remainder of two tanks and called it a night as things were getting dark.
I am going to take the engine off and check out the rod for any wear. So far so good. If this performance keeps up my jaw is going to hit the pavement that first flight.
Bricks man! Bricks!
Spiro
I put my normal two bricks on the skids and opened up the throttle. With the engine running rich it started to shift ominously around and lift off! I had to stop and get heavier bricks. Do you realize the significance of this statement? BRICKS man, I had to get HEAVIER BRICKS. The first set of bricks proved INSUFICIENT! I was awe struck.
Just incase there is any question about what we are talking about here, I have attached some photos. The Vmax7, during break in and running rich, proved too manly for the bricks on the left. The bricks on the right held things under control, but the plastic landing skids were flexing with some serious protest. That is the Vmax6 in the foreground for reference.
Once I had some beefy enough BRICKS for the job, (wow), I fired it back up and put tach under the blades. My ears were not deceiving me, I was getting near 2200 rpm at the head! Manufacturers instructions or not I could not comfortably let the engine run wide open during the break in process at %110 speed. I throttled back for the remainder of two tanks and called it a night as things were getting dark.
I am going to take the engine off and check out the rod for any wear. So far so good. If this performance keeps up my jaw is going to hit the pavement that first flight.
Bricks man! Bricks!
Spiro
06-19-2003, 01:38 AM
#46
Senior Member
Thread Starter
Join Date: Dec 2002
Location: Munford, TN
Posts: 1,169
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
I like your last post Spiro, gotta good laugh about the bricks. i was saying all along the V7 has some really good power. Youre gonna get a kick out of it. i hope you dont throw a rod. You definitely dont have to worry about the heli being under powered thats for sure. Im on some down time waiting on a clutch bell and shoes. I litterally wore them out . The V7 breathes a breath of new life in the LMH. Its all fun and games now.
. The V7 breathes a breath of new life in the LMH. Its all fun and games now.
06-22-2003, 02:57 AM
#47
Join Date: Apr 2003
Location: Mesa, AZ
Posts: 588
Likes: 0
Received 0 Likes
on
0 Posts
Plick!
I now know the exact sound a heart makes when it breaks. I would have never thought it would be so tiny and pathetic.
My con rod went on the 4th tank of fuel while breaking things in. The engine just stopped cold and the blades spun down along with all of my hopes and dreams. I must admit this makes me pretty sad and rather leery of the whole Vmax7 business. It seemed that the “bad” engines had been mostly found out and the newer engines and replacements were running strong. Now I am once again unable to fly. The lure of electrics is growing stronger.
Spiro
“Not with a bang but a whimper.” T.S. Eliot
http://www.cs.umbc.edu/~evans/hollow.html
My con rod went on the 4th tank of fuel while breaking things in. The engine just stopped cold and the blades spun down along with all of my hopes and dreams. I must admit this makes me pretty sad and rather leery of the whole Vmax7 business. It seemed that the “bad” engines had been mostly found out and the newer engines and replacements were running strong. Now I am once again unable to fly. The lure of electrics is growing stronger.
Spiro
“Not with a bang but a whimper.” T.S. Eliot
http://www.cs.umbc.edu/~evans/hollow.html
06-22-2003, 04:03 AM
#48
Senior Member
Thread Starter
Join Date: Dec 2002
Location: Munford, TN
Posts: 1,169
Likes: 0
Received 0 Likes
on
0 Posts
LMH Vmax 7 engine
Call LiteMachines and send it back. So far on the LMH BBS one of the most talked about problems is the V7 con rod. The attention that it has been getting Im sure hasent been good for sales im sure. hate to hear that its still going on. One of these days there will come along an engine thats more reliable. Its appearant that its an obvious QC problem that it will be hard to ignore. Ive noticed that the bad engines usually have been throwing rods at about 4-8 tanks of gas. What I hate the most is the downtime waiting on replacement. Im like you Spiro, the electric seemingly is calling. Ive started one and got one going I need to get a better battery that my esc would like. so far Im reading that the stock motor and esc likes the 2400 7 cell pack. Hopefully I can aquire one soon.
06-23-2003, 04:48 AM
#49
Join Date: Apr 2003
Location: Mesa, AZ
Posts: 588
Likes: 0
Received 0 Likes
on
0 Posts
Pics
If anyone would like to take a close look, I took a few hires pics of my engine post rod failure. The .jpg files have been zipped into a single 5MB file found at:
http://www.public.iastate.edu/~spiro...RodFailure.zip
For what it is worth, (squat at this point)
Spiro
http://www.public.iastate.edu/~spiro...RodFailure.zip
For what it is worth, (squat at this point)
Spiro
06-23-2003, 04:51 PM
#50
Senior Member
My Feedback: (7)
Join Date: Jan 2002
Location: Eatoville, WA
Posts: 679
Likes: 0
Received 0 Likes
on
0 Posts
Way to long to open
Can you post a pic, these take forever on a dail up, Iam very interested, especially cause I think Norvel is wrong on there break-in proceeder, Thanks Fastlash
