Beware of the SV50 single !
03-21-2008, 02:40 PM
#1
Beware of the SV50 single !
We got a new SV50 single from Hobby City, and within 20 seconds of running, it cracked the side of the fuse of our brand new Pacific Aeromodels Cliped Wing Monocoupe, broke off 3 of the 4 engines mounting ears, and destroyed a new Zinger prop as well. Yikes ! Dennis
03-21-2008, 03:17 PM
#2
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RE: Beware of the SV50 single !
It sounds like more of a problem with the monocope than the engine. Why do you think the motor was the problem rather than the firewall, or prop? Not challanging you or anything, just wondering. More details, please and photds!!
Mike
Mike
03-21-2008, 03:41 PM
#3
RE: Beware of the SV50 single !
I said what I have to say. This is not our first rodeo. Im new to gas more less, but not my bud, he's been flying gas for years, and were both retired mechanics. Sorry, with all the instant destruction, we didn't have time to take any pics or video of it. He put a FTL45 on the Monocoupe shortly after, and it's nice and smooth with the same prop. Lets let some other happy SV50 owners chime in now. The point is, we got a defective one, but they expect us to pay the return shipping (about $50.00). Nope, were keeping it as a reminder. That engine has cost us too much already, and we sure don't want anything else from Hobby City, so were going to just write it off and not look back. We just don't want anyone else to go thru what we have. Thats what these forums are all about. Dennis
03-21-2008, 04:01 PM
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RE: Beware of the SV50 single !
Yep, it must of been the Monocoupe! ROFL 
You where lucky! It waited until I took off to break the lugs, and just about destroy my Wild Hare Sukhoi. You gotta say away from those cheap $500 ARFs a Monocoupe and a Sukhoi, both must of been junk![:'(][:'(]
You where lucky! It waited until I took off to break the lugs, and just about destroy my Wild Hare Sukhoi. You gotta say away from those cheap $500 ARFs a Monocoupe and a Sukhoi, both must of been junk![:'(][:'(]
03-21-2008, 04:02 PM
#6
RE: Beware of the SV50 single !
They used 2 different crankshafts in the SV50's. One has the rod placed between to counterweights, and those are smooth. The junk we got has one counterweight with a pin, and the rod is held onto the pin buy a button which is riveted on thru the rod pin. Those are the one's that shake violently, and we were unlucky enough to get one. Dennis
03-21-2008, 04:07 PM
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RE: Beware of the SV50 single !
I've never seen one that was held on between crank jounals. The early ones were smooth but the con rod fell off the crank at TDC, thats why the button on the crank. The button on the crank was a shaker, the early one ran very smoothly 6200 rpm wih a 22x8, but I put a pipe on it and it blew up.
03-21-2008, 04:39 PM
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RE: Beware of the SV50 single !
Just for the heck of it, how many of these cloned engines have actual bearings at either end of the connecting rod? I have a 100cc cloned twin I picked up to try and it seems that all the good stuff that the original design had that made them good was removed for cloning, including the rod and wrist pin bearings. I guess they believe bushings are better?
03-21-2008, 04:57 PM
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RE: Beware of the SV50 single !
ORIGINAL: Pat Roy
including the rod and wrist pin bearings. I guess they believe bushings are better?
including the rod and wrist pin bearings. I guess they believe bushings are better?
03-21-2008, 05:42 PM
#12
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RE: Beware of the SV50 single !
ORIGINAL: soarrich
If they did that it was just a straight rip-off, not just stupidity, everyone knows you can't use bushings in a two stroke gasser. Fuel engines get away with it, but they use 10 times the oil. The big StupidTigre fuelies even have needle bearings.
ORIGINAL: Pat Roy
including the rod and wrist pin bearings. I guess they believe bushings are better?
including the rod and wrist pin bearings. I guess they believe bushings are better?
03-21-2008, 06:08 PM
#13
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RE: Beware of the SV50 single !
At 32-1 a lower rpm, reduced load application works if they have a cooling air source directed to the engine as such industrial uses generally do. Look at glow engines. The reason they require such a high (18-20%) oil content in the fuel is largely due to the use of bushings instead of bearings. Bearings for glow engines would need to be extremely small and are therefore impractical on a cost basis alone. Bushings work, but you need lots of oil. Doing the same in a gasser means you end up with a giant slimer if you want the engine to last any leagth of time. You saved some money on the engine but dramatically increased your recurring bed spread expenses for clean up.
I have to admit that pulling three bearings from a twin design dramatically reduces the end production cost, but it makes me wonder a little about how much concern the manufacturer has for the consumer. I suppose if your intent is to provide a single season of flying with constantly decreasing performance with an engine it works out but long term use probably isn't on the list. Just one more thing to consider when we see those ultra cheap imported engine prices. You truly need to be aware of what's inside them.
This is leading up (eventually) to an engine review that's going to cost me dearly. Then again, I'm already out for the price of the engine.
I have to admit that pulling three bearings from a twin design dramatically reduces the end production cost, but it makes me wonder a little about how much concern the manufacturer has for the consumer. I suppose if your intent is to provide a single season of flying with constantly decreasing performance with an engine it works out but long term use probably isn't on the list. Just one more thing to consider when we see those ultra cheap imported engine prices. You truly need to be aware of what's inside them.
This is leading up (eventually) to an engine review that's going to cost me dearly. Then again, I'm already out for the price of the engine.
03-21-2008, 06:36 PM
#15
My Feedback: (19)
RE: Beware of the SV50 single !
ORIGINAL: Pat Roy
At 32-1 a lower rpm, reduced load application works if they have a cooling air source directed to the engine as such industrial uses generally do. Look at glow engines. The reason they require such a high (18-20%) oil content in the fuel is largely due to the use of bushings instead of bearings. Bearings for glow engines would need to be extremely small and are therefore impractical on a cost basis alone. Bushings work, but you need lots of oil. Doing the same in a gasser means you end up with a giant slimer if you want the engine to last any leagth of time. You saved some money on the engine but dramatically increased your recurring bed spread expenses for clean up.
I have to admit that pulling three bearings from a twin design dramatically reduces the end production cost, but it makes me wonder a little about how much concern the manufacturer has for the consumer. I suppose if your intent is to provide a single season of flying with constantly decreasing performance with an engine it works out but long term use probably isn't on the list. Just one more thing to consider when we see those ultra cheap imported engine prices. You truly need to be aware of what's inside them.
This is leading up (eventually) to an engine review that's going to cost me dearly. Then again, I'm already out for the price of the engine.
At 32-1 a lower rpm, reduced load application works if they have a cooling air source directed to the engine as such industrial uses generally do. Look at glow engines. The reason they require such a high (18-20%) oil content in the fuel is largely due to the use of bushings instead of bearings. Bearings for glow engines would need to be extremely small and are therefore impractical on a cost basis alone. Bushings work, but you need lots of oil. Doing the same in a gasser means you end up with a giant slimer if you want the engine to last any leagth of time. You saved some money on the engine but dramatically increased your recurring bed spread expenses for clean up.
I have to admit that pulling three bearings from a twin design dramatically reduces the end production cost, but it makes me wonder a little about how much concern the manufacturer has for the consumer. I suppose if your intent is to provide a single season of flying with constantly decreasing performance with an engine it works out but long term use probably isn't on the list. Just one more thing to consider when we see those ultra cheap imported engine prices. You truly need to be aware of what's inside them.
This is leading up (eventually) to an engine review that's going to cost me dearly. Then again, I'm already out for the price of the engine.
03-21-2008, 07:14 PM
#18
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RE: Beware of the SV50 single !
Based on what I believe the engine was cloned from the count would be 2 rod and 1 main. That leaves you with a 2 bearing crank supporting two opposed cylinders, with no bearings for the rods. The way the aft crank bearing is raced you don't ever want to have a prop strike. You won't have to worry about a bent crank, that's a given, but you might have a devil of a time removing the rear bearing from the reeds. It will have been driven into them...
Then again, the design is young and has room (a lot) for improvement. I'm sorta like CH. I don't want to do R&D for anyone unless I'm getting paid for it. That's why a review hasn't been posted yet. It would work for R&D purposes, and I'm hoping that the manufacturer will eventually send me the parts that were defective when it first arrived to make for a more fair review. I've heard rumors that this may happen but nothing definitive after almost two weeks from the time I first made mention of them. Seems it takes at least a week for an e-mail to get looked at, and longer still if a reply is requested. Even longer if "customer support" may be required.
I'm not going to mention the manufacturers name yet, but if you're a Chinese manufacturer do you hear what's being said?
Then again, the design is young and has room (a lot) for improvement. I'm sorta like CH. I don't want to do R&D for anyone unless I'm getting paid for it. That's why a review hasn't been posted yet. It would work for R&D purposes, and I'm hoping that the manufacturer will eventually send me the parts that were defective when it first arrived to make for a more fair review. I've heard rumors that this may happen but nothing definitive after almost two weeks from the time I first made mention of them. Seems it takes at least a week for an e-mail to get looked at, and longer still if a reply is requested. Even longer if "customer support" may be required.
I'm not going to mention the manufacturers name yet, but if you're a Chinese manufacturer do you hear what's being said?
03-21-2008, 07:29 PM
#19
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RE: Beware of the SV50 single !
Hey Dennis, ,
I wasn't trying to say that the plane was junk or that it was your first rodeo ( I look at the number of posts aperson has and the number of years experience) . What I was saying was what it sounded like to me, but I read something different than what you wrote... I entirely missed the part about the broken motor mount EARS I was reading that the motor mounts had pulled through the firewall. When I saw the picture of Soarrich's Sukoi I went back and read you original post. OOPS[sm=what_smile.gif].
That's why I like pictures, I understand better that way. I appriciate the heads up... no SV50's for me.
Mike
I wasn't trying to say that the plane was junk or that it was your first rodeo ( I look at the number of posts aperson has and the number of years experience) . What I was saying was what it sounded like to me, but I read something different than what you wrote... I entirely missed the part about the broken motor mount EARS I was reading that the motor mounts had pulled through the firewall. When I saw the picture of Soarrich's Sukoi I went back and read you original post. OOPS[sm=what_smile.gif].
That's why I like pictures, I understand better that way. I appriciate the heads up... no SV50's for me.
Mike
03-21-2008, 08:01 PM
#21
RE: Beware of the SV50 single !
Yeah, that pic he put up pretty much tells it all. Anyone who hasn't seen one of these engine running, could never even imagine how much they shake. It would blow your mind... lol
What I find interesting is that Hobby City won't answer their phone during their business hours most of the time. I have gotten lucky a few times in the last couple of months, but then all I got was empty promises and lies.
What I find interesting is that Hobby City won't answer their phone during their business hours most of the time. I have gotten lucky a few times in the last couple of months, but then all I got was empty promises and lies.
03-21-2008, 08:05 PM
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RE: Beware of the SV50 single !
ORIGINAL: Pat Roy
I would have loved to have been there to hear the comments at the time[X(]
I would have loved to have been there to hear the comments at the time[X(]
03-22-2008, 09:35 AM
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RE: Beware of the SV50 single !
Oddly enough it's yet another sad ending of a cheap engine... I wish more people would pay attention and stop throwing their money away.
