BJ CRAFT new plane Invitation...
02-23-2015, 03:55 PM
#26
Senior Member
That's the muffler I bought for my GT33 and I don't think it was designed for the OS in particular, but I decided to give it a go.
Have you tried the 20.5 X 10? That's the prop I'm gong to try. I'm thinking it should give around the same RPM as the 19.5 X 11.5?
I'm getting that RPM with a 20.5 X 10 on my 185cdi, so if the 33 can get close to it using that muffler, it should be OK.
Have you tried the 20.5 X 10? That's the prop I'm gong to try. I'm thinking it should give around the same RPM as the 19.5 X 11.5?
I'm getting that RPM with a 20.5 X 10 on my 185cdi, so if the 33 can get close to it using that muffler, it should be OK.
One thing to keep in mind is the type of gas one uses will make a difference in maximum output. The same gasoline mix as above is what I generally use on the 33 turning the 20x10.5 Narrow. I get about 7400 on that set-up.
I ran premium auto gas a couple years ago (same oil and ratio) just because and got about 7800 rpm for the 20x10.5. I decided I really hated the stench of auto gas and didn't need the extra power so I went back to Avgas ever since and have no plan to change, ever again.
02-23-2015, 05:07 PM
#27
Scott, I've run the apc narrow blade 20.5x10 on the CDI/ GT33/ pipe combo. The gasoline I use is Avgas mixed with a good racing synthetic at 50:1. I got 7200 max rpm, an rpm number we don't hardly ever need or use. I also tried the 21x10 apc and rpm dropped off to around 6700 which was bunch. The engine just didn't sound happy.
One thing to keep in mind is the type of gas one uses will make a difference in maximum output. The same gasoline mix as above is what I generally use on the 33 turning the 20x10.5 Narrow. I get about 7400 on that set-up.
I ran premium auto gas a couple years ago (same oil and ratio) just because and got about 7800 rpm for the 20x10.5. I decided I really hated the stench of auto gas and didn't need the extra power so I went back to Avgas ever since and have no plan to change, ever again.
One thing to keep in mind is the type of gas one uses will make a difference in maximum output. The same gasoline mix as above is what I generally use on the 33 turning the 20x10.5 Narrow. I get about 7400 on that set-up.
I ran premium auto gas a couple years ago (same oil and ratio) just because and got about 7800 rpm for the 20x10.5. I decided I really hated the stench of auto gas and didn't need the extra power so I went back to Avgas ever since and have no plan to change, ever again.
I was planning on running premium, but 7800 is not needed so I might just go with Avgas from the start and see how that goes. Running the muffler will be a little less RPM, but if I can get around 6900 I think that will be OK. Thanks for the info.
I've been using the Tech Aero IBEC for a few years on my YS cdi's. Saves the weight of an extra battery and not one problem.
Yes I have to agree, Avgas does smell much better.
02-24-2015, 03:18 PM
#28
Senior Member
Scott, don't forget that my numbers are on a piped GT33. I see guys reporting much less on the stock muffler, for 19" props. All things being equal, it seems to me the pipe boost is about 1000 rpm over the stock muffler. But the Hatori canister is indicating intriguing numbers.
The IBEC has many advantages and weight reduction is one good one. But for an older guy like me, the safety aspects are most important. I've been preaching this to sport fliers for several years now but I swear they are deaf.
Back to Sungo for a moment, if you do get to play with the OS glow plug on the GT33, please report back with details....muffler versus pipe, type of gasoline and oil including ratio, props, etc
The IBEC has many advantages and weight reduction is one good one. But for an older guy like me, the safety aspects are most important. I've been preaching this to sport fliers for several years now but I swear they are deaf.
Back to Sungo for a moment, if you do get to play with the OS glow plug on the GT33, please report back with details....muffler versus pipe, type of gasoline and oil including ratio, props, etc
02-24-2015, 04:43 PM
#29
Scott, don't forget that my numbers are on a piped GT33. I see guys reporting much less on the stock muffler, for 19" props. All things being equal, it seems to me the pipe boost is about 1000 rpm over the stock muffler. But the Hatori canister is indicating intriguing numbers.
The IBEC has many advantages and weight reduction is one good one. But for an older guy like me, the safety aspects are most important. I've been preaching this to sport fliers for several years now but I swear they are deaf.
Back to Sungo for a moment, if you do get to play with the OS glow plug on the GT33, please report back with details....muffler versus pipe, type of gasoline and oil including ratio, props, etc
The IBEC has many advantages and weight reduction is one good one. But for an older guy like me, the safety aspects are most important. I've been preaching this to sport fliers for several years now but I swear they are deaf.
Back to Sungo for a moment, if you do get to play with the OS glow plug on the GT33, please report back with details....muffler versus pipe, type of gasoline and oil including ratio, props, etc
03-15-2015, 01:31 AM
#30
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Have been playing with the new os plug. Have just ran on the ground so far, but numbers look just as good as the ignition. Actually seems to run pretty well so far. May get a chance to get it in the air in the next couple days.
03-16-2015, 08:53 AM
#32
Senior Member
I hear what you are saying. We know that the YS big block 4 strokes are more frugal when being run on ignition. But that's glow fuel.
RM should be able to tell us some of these particulars such as what exhaust system, what prop and rpm, and what carb changes if any. It may all be moot though since my 33's run 20+ minutes on about 10 ozs of gasoline....I never use full throttle for 11 lb airplane. So even if we lost 5 minutes of run time if we had to run a slight bit richer, it's not a big loss. But of course that's only my opinion.
No matter what, I see the glow plug in my future developments as well. This new thingy from OS is most intriguing. If it works as advertised and keeps a good idle and transition long term, it will shave about 4-5 ounces from the CDI set-up with IBEC. And that's great news....Then my Delta will be less than 10 pounds.
03-17-2015, 07:27 PM
#35
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Joe
Thanks, most of my necessary parts are arrived. it's about to time for building up.
I will post the proccedure of modifing the engine mount area.. we need some modification a lot.
Sungho
Thanks, most of my necessary parts are arrived. it's about to time for building up.
I will post the proccedure of modifing the engine mount area.. we need some modification a lot.
Sungho
03-17-2015, 07:49 PM
#36
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All my necessary parts are arrived, and got in my hand, G-5 glow plug and converting adaptor, prop, servor, everything.
Invitation is not designed for GT33, so every engine mount parts should be re-designed modified. so, I will use my own designed hyde-type mount,
and bulk head, nose-ring etc.. it took a lot of time. now it's almost done.. so I can build them up. I will post the pictures of proccedure from now on.
Invitation is not designed for GT33, so every engine mount parts should be re-designed modified. so, I will use my own designed hyde-type mount,
and bulk head, nose-ring etc.. it took a lot of time. now it's almost done.. so I can build them up. I will post the pictures of proccedure from now on.
03-20-2015, 06:32 PM
#37
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Got a chance to fly today.
48 deg f. Calm winds. Actually a fairly nice day.
This is a new motor, a little over 3 gallons through it.
Fuel 83 octane, stihl hp ultra @ 40:1 (Fuel is left over from last october with stabilizer added)
Hatori pipe
RPM's taken at end of flight when motor nicely warm
19.5x11.5 APC. ...... 7000
20.5 x10 apc . ...... 6800
These rpm's are pretty close to the ign #'s.
Flights were 11 Minutes. Fuel consumption looked to be same. 11oz tank had just under 1/2 tank remaining.
Idle was good, transitions were good, started easy, i use elec starter. Didn't have any problems at all With the new plug.
Lookin like a winner to me. Look forward to seeing what others come up with.
One other thought. Without the ign drain i was avg 130mah/flight. Currently using 1100 life, would be able to goto a 700mah pak and be able to save close to another ounce if adv wt is correct.
48 deg f. Calm winds. Actually a fairly nice day.
This is a new motor, a little over 3 gallons through it.
Fuel 83 octane, stihl hp ultra @ 40:1 (Fuel is left over from last october with stabilizer added)
Hatori pipe
RPM's taken at end of flight when motor nicely warm
19.5x11.5 APC. ...... 7000
20.5 x10 apc . ...... 6800
These rpm's are pretty close to the ign #'s.
Flights were 11 Minutes. Fuel consumption looked to be same. 11oz tank had just under 1/2 tank remaining.
Idle was good, transitions were good, started easy, i use elec starter. Didn't have any problems at all With the new plug.
Lookin like a winner to me. Look forward to seeing what others come up with.
One other thought. Without the ign drain i was avg 130mah/flight. Currently using 1100 life, would be able to goto a 700mah pak and be able to save close to another ounce if adv wt is correct.
Last edited by rm; 03-20-2015 at 06:39 PM.
03-21-2015, 02:09 AM
#39
Got a chance to fly today.
48 deg f. Calm winds. Actually a fairly nice day.
This is a new motor, a little over 3 gallons through it.
Fuel 83 octane, stihl hp ultra @ 40:1 (Fuel is left over from last october with stabilizer added)
Hatori pipe
RPM's taken at end of flight when motor nicely warm
19.5x11.5 APC. ...... 7000
20.5 x10 apc . ...... 6800
These rpm's are pretty close to the ign #'s.
Flights were 11 Minutes. Fuel consumption looked to be same. 11oz tank had just under 1/2 tank remaining.
Idle was good, transitions were good, started easy, i use elec starter. Didn't have any problems at all With the new plug.
Lookin like a winner to me. Look forward to seeing what others come up with.
One other thought. Without the ign drain i was avg 130mah/flight. Currently using 1100 life, would be able to goto a 700mah pak and be able to save close to another ounce if adv wt is correct.
48 deg f. Calm winds. Actually a fairly nice day.
This is a new motor, a little over 3 gallons through it.
Fuel 83 octane, stihl hp ultra @ 40:1 (Fuel is left over from last october with stabilizer added)
Hatori pipe
RPM's taken at end of flight when motor nicely warm
19.5x11.5 APC. ...... 7000
20.5 x10 apc . ...... 6800
These rpm's are pretty close to the ign #'s.
Flights were 11 Minutes. Fuel consumption looked to be same. 11oz tank had just under 1/2 tank remaining.
Idle was good, transitions were good, started easy, i use elec starter. Didn't have any problems at all With the new plug.
Lookin like a winner to me. Look forward to seeing what others come up with.
One other thought. Without the ign drain i was avg 130mah/flight. Currently using 1100 life, would be able to goto a 700mah pak and be able to save close to another ounce if adv wt is correct.
What is the midrange torque like? How much throttle are you using in the verticals?
03-21-2015, 10:54 AM
#40
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I think the midrange is pretty good, especially for a 2 stroke. I've been trying to fly a constant type speed with it, so I spend a lot of flying time at mid throttle and have my curve set up for that, thus when I'm entering the verticals I'm usually going to full stick because I don't have the speed to carry me. These are the masters maneuvers I fly. With the 20.5" prop, controlling the speed is a lot easier. If I was worried about vertical I'd go with the 19.5", but it's a faster prop and harder to control the overall speed as it doesn't downline brake as well. With the 19.5" I can go into a hover, and power out of it while doing point rolls straight up with authority, not crawling. This is all in really good air, haven't tried it in real hot conditions. Last summer I thought the 20.5" got marginal in some up lines during real hot conditions, but now I'm about 5 oz lighter so will have to see what it does when the time comes.
One other thing flying at reduced throttle so much, I do get into the midrange on the carb and get the rich sounding motor gurgle. I've leaned the low end some to try and help it, but the sound is still there so far.
I'd also recommend the 1" throttle arm extension. My throttle curve right now is nearly linear with it, bumped up a little on the low end side. With the 1/2" arm my curve was nearly flat throughout the midrange.
One other thing flying at reduced throttle so much, I do get into the midrange on the carb and get the rich sounding motor gurgle. I've leaned the low end some to try and help it, but the sound is still there so far.
I'd also recommend the 1" throttle arm extension. My throttle curve right now is nearly linear with it, bumped up a little on the low end side. With the 1/2" arm my curve was nearly flat throughout the midrange.
03-21-2015, 11:13 AM
#41
I think the midrange is pretty good, especially for a 2 stroke. I've been trying to fly a constant type speed with it, so I spend a lot of flying time at mid throttle and have my curve set up for that, thus when I'm entering the verticals I'm usually going to full stick because I don't have the speed to carry me. These are the masters maneuvers I fly. With the 20.5" prop, controlling the speed is a lot easier. If I was worried about vertical I'd go with the 19.5", but it's a faster prop and harder to control the overall speed as it doesn't downline brake as well. With the 19.5" I can go into a hover, and power out of it while doing point rolls straight up with authority, not crawling. This is all in really good air, haven't tried it in real hot conditions. Last summer I thought the 20.5" got marginal in some up lines during real hot conditions, but now I'm about 5 oz lighter so will have to see what it does when the time comes.
One other thing flying at reduced throttle so much, I do get into the midrange on the carb and get the rich sounding motor gurgle. I've leaned the low end some to try and help it, but the sound is still there so far.
I'd also recommend the 1" throttle arm extension. My throttle curve right now is nearly linear with it, bumped up a little on the low end side. With the 1/2" arm my curve was nearly flat throughout the midrange.
One other thing flying at reduced throttle so much, I do get into the midrange on the carb and get the rich sounding motor gurgle. I've leaned the low end some to try and help it, but the sound is still there so far.
I'd also recommend the 1" throttle arm extension. My throttle curve right now is nearly linear with it, bumped up a little on the low end side. With the 1/2" arm my curve was nearly flat throughout the midrange.
It will be interesting to see the comparison. I will be putting it in the same model with the YS, so it will be comparing apples to apples.
03-30-2015, 07:30 PM
#43
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I flew Alex Shim's Invitation at Orange County this past weekend. It is very rare for me to fly someone's model and not want to recommend changing things. I could find nothing wrong with his model. The YS 1.75 was maybe a little light on power for F3A sequences, especially the finals routines. But the model did everything extremely well. I think this will be an easy model to like!
03-30-2015, 10:10 PM
#44
I flew Alex Shim's Invitation at Orange County this past weekend. It is very rare for me to fly someone's model and not want to recommend changing things. I could find nothing wrong with his model. The YS 1.75 was maybe a little light on power for F3A sequences, especially the finals routines. But the model did everything extremely well. I think this will be an easy model to like!
03-30-2015, 11:46 PM
#45
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I am with you on this one .....YS 175 is a very powerful engine.
I fly a slightly overweight XIGRIS with my 175 and I haven't yet used more than 3/4 throttle
03-30-2015, 11:46 PM
#46
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Just my opinion from the one flight I had with the model. Perhaps everything has not yet been optimized on Alex's new model. He flew it one flight before the contest then 4 rounds of the contest and then I flew it. Very early in the process.
03-31-2015, 07:09 AM
#47
Lot's of volume on that plane, perhaps it's a prop. selection process or a fuel change, who knows? My concern's would be with all the rolling vertical figures in the K-6 and a few in the F-15 program (like Tony mentioned). I have spoke to a few pilots flying the YS-185 and it's insane power..... We will see what a YS-170 with a hyper piston will do.....
I am waiting on the different swept wings and a slightly revised color scheme.
Bill H.
I am waiting on the different swept wings and a slightly revised color scheme.
Bill H.
Last edited by AmericanSpectre505; 03-31-2015 at 07:25 AM.
03-31-2015, 06:40 PM
#49
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Alex sent me some pics of his Invitation, the one I flew this past weekend. As I said I found it to be an excellent flying model. It wouldn't take me very long to get hooked up with this plane. Plus I really like the scheme on this model and the Essence. Very pleasing and very visible.
