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Hottest .91-.120?
Hey,
A buddy and I are thinking of building a plane a la SpeedCup and I would like a little engine info. What is the strongest .91-1.20 size engine suited for this? Jett, Rossi, Picco, REX. Price not really a concern, just want the best I can get. Cheers |
RE: Hottest .91-.120?
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RE: Hottest .91-.120?
Great...thanks for the link! Any real performance #'s or actual experiences?
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RE: Hottest .91-.120?
5.5bhp at 630g seems good, duno how much that 120 would drink a minute?
24k! |
RE: Hottest .91-.120?
I know....sounds tasty! Only need a 3-4 minute flight.
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RE: Hottest .91-.120?
Looks like a sweet one can't figure out where to find a price! 24k is amazing
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RE: Hottest .91-.120?
For reference an OPS .65 + open pipe on the bench with a 7x10 CF break-in prop goes through a bit over 4oz a minute. I would suspect that 1.20 at full song would be sucking 6-7 oz a minute, probably closer to 7, based on the relative rated outputs.
The .65 is the thirstiest glow engine I have ever run in my life.. :). I know there are thirstier, but not in my stable. You can see the fuel level move in the tank, it's over 2cc per second which is a real pretty sight because it's power in the making. MJD |
RE: Hottest .91-.120?
wow, so what size tank for SD?
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RE: Hottest .91-.120?
I am converting a Hangar9 11-ounce rectangular tank to bladder, by heal-sealing up my own bladder for it. I've been messing with that lately and having pretty good success. And am now looking into upgrading the status quo for sealing equipment so I can make it easy. Luckily I have connections in the food packaging industry.. :D
This should give me enough time for start up, run for cover, pull the lanyard, fly around madly for 2:00 - 2:30, then land. That's probably going to feel like plenty long enough and I'll be surprised if I burn out the first tank, I'll be worried about setting it up for landing #1. I am trying to set up the IMC to act as a kill with enough travel - it closes off fairly rapidly at the lean end, and I think I can fiddle servo overdrive and linkage geometry to give me good resolution during flight mixture control and the ability to chop the fuel off in a servo's travel time. Gonna try, the blow test on the bench says it should work. I realized that a Dubro fueling valve is perfect for 2 line bladder installs, because it shuts off the tank-to-mixture control circuit and connects the fueler to the now isolated tank. Well duh Mike, ain't you a friggin' pioneer in fuel system layout :eek:. Anyhow, I also decided I would leave it off for now, to avoid the temptation to get complacent on the first day. CP warned me against this, and knowing my habits I had a suspicion that making it too easy to refuel and fly is a bad thing when you have a highly refined high frequency vibration generator up front of a new machine with about zilch mass to soak up the shakes. Land, clean, cowl off, inspect, fix n fondle, refuel, cowl on, fly it again or seek medical assistance as the case may warrant. MJD |
RE: Hottest .91-.120?
i spent 3-4 months ordering and waiting on the .90 bi metal OPS aero version. it arrived in the marine version and i sent it back[&o]. they haven't emailed me to let me know that the air version is available yet.
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RE: Hottest .91-.120?
That should be a good setup what plane are you going to run it on? I emailed mantua model to try to get a price on the 1.20 but no word yet, sounds like she might be a thirsty onehttp://www.rcuniverse.com/forum/js/f...sn/biggrin.gif
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RE: Hottest .91-.120?
ORIGINAL: MJD I am converting a Hangar9 11-ounce rectangular tank to bladder, by heal-sealing up my own bladder for it. I've been messing with that lately and having pretty good success. And am now looking into upgrading the status quo for sealing equipment so I can make it easy. Luckily I have connections in the food packaging industry.. :D This should give me enough time for start up, run for cover, pull the lanyard, fly around madly for 2:00 - 2:30, then land. That's probably going to feel like plenty long enough and I'll be surprised if I burn out the first tank, I'll be worried about setting it up for landing #1. I am trying to set up the IMC to act as a kill with enough travel - it closes off fairly rapidly at the lean end, and I think I can fiddle servo overdrive and linkage geometry to give me good resolution during flight mixture control and the ability to chop the fuel off in a servo's travel time. Gonna try, the blow test on the bench says it should work. I realized that a Dubro fueling valve is perfect for 2 line bladder installs, because it shuts off the tank-to-mixture control circuit and connects the fueler to the now isolated tank. Well duh Mike, ain't you a friggin' pioneer in fuel system layout :eek:. Anyhow, I also decided I would leave it off for now, to avoid the temptation to get complacent on the first day. CP warned me against this, and knowing my habits I had a suspicion that making it too easy to refuel and fly is a bad thing when you have a highly refined high frequency vibration generator up front of a new machine with about zilch mass to soak up the shakes. Land, clean, cowl off, inspect, fix n fondle, refuel, cowl on, fly it again or seek medical assistance as the case may warrant. MJD I'm curious to the rush in those 2-2.5mins, how intense, when set up? Defo, first day or first flight, trim and dont push it. check her over, get used to her, them hammer her hard,you know the score but may need reiminder after all that work. Will you use, rudder trim for inflight h/s needle? That on a switch too? Throttle trim or throttle cut could kill,instead of inflight mixture servo trim? Jr/spectrum-futaba? |
RE: Hottest .91-.120?
ORIGINAL: donnyb707 Looks like a sweet one can't figure out where to find a price! 24k is amazing MJD has a fun project, and its going to work well. But keep in mind, there is nothing easy about that setup. Its all trial and error and testing. Always take the HP numbers and performance specs with a grain of salt - even for OPS. I can get a SJ-90L to turn 21-22K too .... (have done it in a dmax fan actually - more like 21K rpm though). But its obvious that moving from that to a useful prop-driven configuration is not exactly the same. |
RE: Hottest .91-.120?
I use a Futaba 9C Tx so I have three knobs to choose from for mixture, plus the little lever on the side. Haven't decided yet which to use, but whatever feels right is what it will be. Likely the closet pot knob up and to the right of throttle - with the throttle pinned my fingers are already right about there anyways.
MJD |
RE: Hottest .91-.120?
Bob, I have a jett 90 for a Alley Cat that should be shipping any day nowhttp://www.rcuniverse.com/forum/js/f...sn/biggrin.gif Is there any thing you guys could build for the speed cup? Were thinking of scratch building a speed cup plane? It would have to be WFO for sure.
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RE: Hottest .91-.120?
ORIGINAL: dhal22 i spent 3-4 months ordering and waiting on the .90 bi metal OPS aero version. it arrived in the marine version and i sent it back[&o]. they haven't emailed me to let me know that the air version is available yet. Who did you buy it from so we can avoid them like the plague. |
RE: Hottest .91-.120?
Red, Talked to my brother in law the molds are no problem I guess thats what his cnc machine was used for before. The table is 4x8 so we should be good there:)
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RE: Hottest .91-.120?
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ORIGINAL: freakingfast ORIGINAL: dhal22 i spent 3-4 months ordering and waiting on the .90 bi metal OPS aero version. it arrived in the marine version and i sent it back[&o]. they haven't emailed me to let me know that the air version is available yet. Who did you buy it from so we can avoid them like the plague. i had better explain. Mantua Models in Great Britain was the retailer. i contacted them about purchasing the .90 size and received a price email reply from them. i then sent them my cc # for a deposit and they placed an order with Mantua in Italy. apparently i just missed the quarterly order. so 3 months later the order was placed, unfortunately they ordered the marine version. when i received it and notified them of the problem they apologized and offered a refund. i sent the engine and pipe back to them and received a refund. they were supposed to email me when the aero version was available but i haven't heard back. it was a beautiful engine. the pipe was enormous, 2' long at least. I-L-J, of course, gave me the instructions on how to convert it but i opted to return it. |
RE: Hottest .91-.120?
now you got me thinking about this engine. i may inquire again about the aero version.[sm=teeth_smile.gif]
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RE: Hottest .91-.120?
Is water cooled head the only difference? They could have just got you a head?
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RE: Hottest .91-.120?
prolly faster t[:-]o get one through the tether car guys, they have direct connections ot the factories....drool
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RE: Hottest .91-.120?
ORIGINAL: mk1spitfire Is water cooled head the only difference? They could have just got you a head? the head and the shaft are/were both marine version and the shaft and carb would have to be swapped around. more than i wanted to do. |
RE: Hottest .91-.120?
ORIGINAL: donnyb707 Bob, I have a jett 90 for a Alley Cat that should be shipping any day now[img][/img] Is there any thing you guys could build for the speed cup? Were thinking of scratch building a speed cup plane? It would have to be WFO for sure. Will not keep up with a rear rotor engine like BVM91 or even the OS91DF (dub stopped making the Fan 95 engine long ago, so no rear rotors). You cant beat rr for stuffing fuel into an engine because you can hollow out the crankshaft, or cut the intake slot large enough without compromising the crankshaft itself. If you are not competing or going for a record, you can use just about any engine you want. |
RE: Hottest .91-.120?
Bob,
The idea is that we will be building a molded plane for the Speed Cup from scratch and are looking for big HP. What do you think the FIRE .90 would turn the 9 x 10 at? I have also thought that a BVM .91 or 1.00 might do pretty well. Looks like the OPS is a beast though! |
RE: Hottest .91-.120?
BVM is a lot easier to get and service. Popular choice for the speed guys.
Figure you might see 16,000-17,000 or so from the Jett 90 set up just right. Maybe a little bit more? And Id try to prop it down in that range anyway. |
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