OS .15 CV-A question.
02-03-2010, 06:43 PM
#51
RE: OS .15 CV-A question.
Yep, even a 6x6 might be too optimistic, it might need more like a 6x5.5.
The nice thing about carbon props is they are easy to modify.
The bad thing is the dust, it has to be controlled.
Eliminator might have the perfect prop right out of the mold, if not he has something pretty close.
A 24 inch span delta like the Screamin' Demon makes an easy airframe to build and play with.
The nice thing about carbon props is they are easy to modify.
The bad thing is the dust, it has to be controlled.
Eliminator might have the perfect prop right out of the mold, if not he has something pretty close.
A 24 inch span delta like the Screamin' Demon makes an easy airframe to build and play with.
01-31-2013, 10:38 PM
#52
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RE: OS .15 CV-A question.
Bringing this back from the dead.
Has anyone come to a conclusion on whether or not the CV-X piston and liner will work in the CV-A? I'm trying to find the most powerful .15 I can for a new project. I would really like to run a car engine in the plane but I can't find one that will work properly.
Has anyone come to a conclusion on whether or not the CV-X piston and liner will work in the CV-A? I'm trying to find the most powerful .15 I can for a new project. I would really like to run a car engine in the plane but I can't find one that will work properly.
01-31-2013, 11:26 PM
#53
RE: OS .15 CV-A question.
The Norvel .15BB, is the strongest .15 sports engine that I have. They have just been a little restrictive with the intake area in the carb, replace that and you'll gain a lot of power.
If you really want a high revving engine on a small prop, then have a look at the dedicated ones from Fora or Rex etc. Rex offers engines built like car engines (5-7 transfer ports) and they make the tune pipes to go with them too.
If you really want a high revving engine on a small prop, then have a look at the dedicated ones from Fora or Rex etc. Rex offers engines built like car engines (5-7 transfer ports) and they make the tune pipes to go with them too.
02-01-2013, 08:54 AM
#54
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RE: OS .15 CV-A question.
WOW the REX engine's are absolutely outstanding in performance; I've gotta have a .15TC and a .21!
Now the real question is, where do I buy one of these in the US or Canada (that will ship to the US)?
Now the real question is, where do I buy one of these in the US or Canada (that will ship to the US)?
02-03-2013, 04:08 PM
#57
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RE: OS .15 CV-A question.
ORIGINAL: Mr Cox
[link=http://www.planethobby.com/collections]Planethobby[/link] ships world-wide.
[link=http://www.planethobby.com/collections]Planethobby[/link] ships world-wide.
Holy Moley those are expensive. That's Parra 2.5cc motor money for a Rossi!
02-03-2013, 05:25 PM
#58
RE: OS .15 CV-A question.
Rossi's were never cheap. In the late 1970's I had to buy two to fly FAI speed. One motor for backup. They were $120 Canadian. I think $75 US or so. Minimum wage was $1.80 an hour. Compared to then, now it is a bargain. only half of a week's work to buy one. Then it was three weeks work. It really cut into the beer money as a kid. CNC machining really makes things affordable. Of course chinese labour helps even more. If you want a Novarossi, there are some rc car motors that can be converted with only a bit of trouble. You have to check which brands, maybe HPI or whatever. Lots of people get tired of the cars and sell them off cheap after they go electric now. OS stuff too. Especially the .12's and .15's.
02-03-2013, 05:51 PM
#59
RE: OS .15 CV-A question.
ORIGINAL: VetteV12
WOW the REX engine's are absolutely outstanding in performance; I've gotta have a .15TC and a .21!
Now the real question is, where do I buy one of these in the US or Canada (that will ship to the US)?
WOW the REX engine's are absolutely outstanding in performance; I've gotta have a .15TC and a .21!
Now the real question is, where do I buy one of these in the US or Canada (that will ship to the US)?
02-03-2013, 05:57 PM
#60
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RE: OS .15 CV-A question.
Haven't found "real world" numbers, but 40k+ rpm's is worth looking into and with peak power at 38k it should spin a 8x4 fast. Thats also the prop they recommend.
02-03-2013, 06:15 PM
#61
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RE: OS .15 CV-A question.
Why would having peak power at 38k mean it can spin an 8-4 fast? Does not compute.
It's not going to spin an 8-4 that fast. Just 24k needs about 1.5hp. Power requirement goes up proportionally to rpm cubed. The .15 will probably crank a 6-4 into the 30's. That's close to a typical F2D prop and those engines run up in the 32-33k regime.
The .21 on a 6x5.5 or thereabouts would give you some serious pitch speed if you get it to 30k or more.
It's not going to spin an 8-4 that fast. Just 24k needs about 1.5hp. Power requirement goes up proportionally to rpm cubed. The .15 will probably crank a 6-4 into the 30's. That's close to a typical F2D prop and those engines run up in the 32-33k regime.
The .21 on a 6x5.5 or thereabouts would give you some serious pitch speed if you get it to 30k or more.
02-03-2013, 06:42 PM
#62
RE: OS .15 CV-A question.
Then there is pipe lengths, type of pipe... My Fora went faster than any other .15 I have, but only 20,500 rpm with a 7-5" but it is happier with something smaller and will respond much better, and get closer to say 30,000. An 8-4 would not get anywhere near that. It may be stronger than anything else though with the 8-4".
02-03-2013, 07:37 PM
#63
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RE: OS .15 CV-A question.
I just figured that if it is set up for peak power at 38k, it must be giving something up in the rpm range of a normal sport prop. But maybe not.. I've been wrong before.
02-03-2013, 08:08 PM
#64
RE: OS .15 CV-A question.
The "high timed" engines with 180 degrees+ on the exhaust and the huge intake tract can't tolerate much load...piped or not piped.
I would guess that a world class, piped .15 could be matched to a sleek RC plane with something like a 5x5 prop. You would find the answer somewhere between 6x5 and 5x5...I think.
If a .15 could turn a 5x5 @ 38,000 you would [possibly] be looking at 170+ mph speeds and 1.2 HP generated.
For the money I'd just do what the control line speed guys are doing.
I would guess that a world class, piped .15 could be matched to a sleek RC plane with something like a 5x5 prop. You would find the answer somewhere between 6x5 and 5x5...I think.
If a .15 could turn a 5x5 @ 38,000 you would [possibly] be looking at 170+ mph speeds and 1.2 HP generated.
For the money I'd just do what the control line speed guys are doing.
02-06-2013, 01:54 PM
#65
RE: OS .15 CV-A question.
Here is a thread with more info, giving props and rpms etc; [link=http://www.rcgroups.com/forums/showthread.php?t=1073318]Novarossi/Rex[/link]
