Gas radial engines
06-17-2014, 04:57 PM
#101
Blair - finally got around to some initial prop testing on modded FG-33R3. Running the Xoar AXIAL (WWI wide wood) I maxed at 8430 RPM with reliable 1500 idle. This is with very little tuning and running rich on top end. Transitions from idle to mid, idle to top and mid to top transitions smooth and quick.
Just received a Falcon 18x6 carbon fiber which I'll test next week when I town. My guess is I may pick up a few hundred RPM?
I think the intake plenum mods make a significant difference!
Cheers
Just received a Falcon 18x6 carbon fiber which I'll test next week when I town. My guess is I may pick up a few hundred RPM?
I think the intake plenum mods make a significant difference!
Cheers
Cheers
Last edited by marksp; 06-18-2014 at 08:19 AM.
06-18-2014, 08:08 AM
#103
Senior Member
06-18-2014, 12:09 PM
#105
Senior Member
06-20-2014, 02:24 AM
#108
Senior Member
06-22-2014, 03:53 AM
#109
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
I had emailed Ray English about this and he suggested that a bigger carby would make the fg33r3 unresponsive, well tonight we started my engine with a Zama 16 43p (8.2mm venturi x16 mm bore) with a robart air tank with a regulator feeding 4psi air pressure to my fuel tank to pump fuel through the carby.
The performance is truly night and day, the exhaust note is so different even my wife noticed, its aggressive at idle lumping 2 cylinders at a time, the progression is better than it has ever been, no miss,pop or hesitation just real performance, it really hammers! 8920rpm turning a 18x6! It
could only muster 8120 rpm 3 days ago with a custom inlet manifold and exhaust.
I've seen much talk about inlets and exhausts but I have now seen how much hp Saito's rubbish carby is robbing from this motor.
Video coming asap.
Last edited by Blair K.; 06-22-2014 at 03:59 AM.
06-22-2014, 05:21 AM
#110
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
Saito FG33R3 with custom exhaust, inlet & carby: http://youtu.be/nExiGT8a8ng
The exhaust recording is not as strong as in the flesh but bang in a pair of earphones and crank it up its pritty close
The exhaust recording is not as strong as in the flesh but bang in a pair of earphones and crank it up its pritty close
Last edited by Blair K.; 06-22-2014 at 05:26 AM.
06-22-2014, 09:25 PM
#112
Quick couple of questions - this is my first non-electric airframe, so I'm still sorting out.
Firstly, I'm experiencing a little oil inside my cowl. It's clear that it's coming from the exhaust elbow connection to the "flexi-tubes". I included the shim when I installed and tightened fairly snug being cautious to not over tighten. Is this normal? Should I tighten more? Re-install with fresh shim?
Secondly, I had my engine modded (Ray English) to optimize fuel flow and cylinder temps. I'm also running the Spektrum on-board ignition RPM sensor and have captured flight logs for every flight. Max in-flight RPM is 9150 and on-ground 8800. This is very close to the Saito manual stated in-flight max of 9500 and on-ground of 9000. Should I consider up sizing my 18x6 carbon fiber prop? Don't want to over rev the engine and a little more thrust for my 21 lb Beaver would be nice.
Cheers
Firstly, I'm experiencing a little oil inside my cowl. It's clear that it's coming from the exhaust elbow connection to the "flexi-tubes". I included the shim when I installed and tightened fairly snug being cautious to not over tighten. Is this normal? Should I tighten more? Re-install with fresh shim?
Secondly, I had my engine modded (Ray English) to optimize fuel flow and cylinder temps. I'm also running the Spektrum on-board ignition RPM sensor and have captured flight logs for every flight. Max in-flight RPM is 9150 and on-ground 8800. This is very close to the Saito manual stated in-flight max of 9500 and on-ground of 9000. Should I consider up sizing my 18x6 carbon fiber prop? Don't want to over rev the engine and a little more thrust for my 21 lb Beaver would be nice.
Cheers
06-22-2014, 11:48 PM
#113
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
Quick couple of questions - this is my first non-electric airframe, so I'm still sorting out.
Firstly, I'm experiencing a little oil inside my cowl. It's clear that it's coming from the exhaust elbow connection to the "flexi-tubes". I included the shim when I installed and tightened fairly snug being cautious to not over tighten. Is this normal? Should I tighten more? Re-install with fresh shim?
Secondly, I had my engine modded (Ray English) to optimize fuel flow and cylinder temps. I'm also running the Spektrum on-board ignition RPM sensor and have captured flight logs for every flight. Max in-flight RPM is 9150 and on-ground 8800. This is very close to the Saito manual stated in-flight max of 9500 and on-ground of 9000. Should I consider up sizing my 18x6 carbon fiber prop? Don't want to over rev the engine and a little more thrust for my 21 lb Beaver would be nice.
Cheers
Firstly, I'm experiencing a little oil inside my cowl. It's clear that it's coming from the exhaust elbow connection to the "flexi-tubes". I included the shim when I installed and tightened fairly snug being cautious to not over tighten. Is this normal? Should I tighten more? Re-install with fresh shim?
Secondly, I had my engine modded (Ray English) to optimize fuel flow and cylinder temps. I'm also running the Spektrum on-board ignition RPM sensor and have captured flight logs for every flight. Max in-flight RPM is 9150 and on-ground 8800. This is very close to the Saito manual stated in-flight max of 9500 and on-ground of 9000. Should I consider up sizing my 18x6 carbon fiber prop? Don't want to over rev the engine and a little more thrust for my 21 lb Beaver would be nice.
Cheers
most IC planes are dirty buggers inside the cowl, got four of em and sooner or later they get oily.
the upside is oil from engine will blow over your plane and its the most scale look you can get.
the rpm I wouldn't be concerned about, they unwind in the air and most of us would never know what rpm they hit, I have 4 Saito's, fly em all flat out all the time cause I love speed, never had one fail even on a 210kph p-40 warhawk, devide 210.3 kph by 8" of pitch and it equals a lot! No issue for it.
try a 18x8 on your thrust meter, we found we lost thrust but I haven't flown on it to give any more info.
06-23-2014, 12:56 AM
#114
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
Quick couple of questions - this is my first non-electric airframe, so I'm still sorting out.
Firstly, I'm experiencing a little oil inside my cowl. It's clear that it's coming from the exhaust elbow connection to the "flexi-tubes". I included the shim when I installed and tightened fairly snug being cautious to not over tighten. Is this normal? Should I tighten more? Re-install with fresh shim?
Secondly, I had my engine modded (Ray English) to optimize fuel flow and cylinder temps. I'm also running the Spektrum on-board ignition RPM sensor and have captured flight logs for every flight. Max in-flight RPM is 9150 and on-ground 8800. This is very close to the Saito manual stated in-flight max of 9500 and on-ground of 9000. Should I consider up sizing my 18x6 carbon fiber prop? Don't want to over rev the engine and a little more thrust for my 21 lb Beaver would be nice.
Cheers
Firstly, I'm experiencing a little oil inside my cowl. It's clear that it's coming from the exhaust elbow connection to the "flexi-tubes". I included the shim when I installed and tightened fairly snug being cautious to not over tighten. Is this normal? Should I tighten more? Re-install with fresh shim?
Secondly, I had my engine modded (Ray English) to optimize fuel flow and cylinder temps. I'm also running the Spektrum on-board ignition RPM sensor and have captured flight logs for every flight. Max in-flight RPM is 9150 and on-ground 8800. This is very close to the Saito manual stated in-flight max of 9500 and on-ground of 9000. Should I consider up sizing my 18x6 carbon fiber prop? Don't want to over rev the engine and a little more thrust for my 21 lb Beaver would be nice.
Cheers
most IC planes are dirty buggers inside the cowl, got four of em and sooner or later they get oily.
the upside is oil from engine will blow over your plane and its the most scale look you can get.
the rpm I wouldn't be concerned about, they unwind in the air and most of us would never know what rpm they hit, I have 4 Saito's, fly em all flat out all the time cause I love speed, never had one fail even on a 210kph p-40 warhawk, devide 210.3 kph by 8" of pitch and it equals a lot! No issue for it.
try a 18x8 on your thrust meter, we found we lost thrust but I haven't flown on it to give any more info.
06-25-2014, 06:12 AM
#116
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
Ok the mods are done, custom ported manifold,custom inlet with 16 x 12.7mm walbro carby.
It starts and idles fine but it was 11 pm so I couldn't give it a hiding, tomorrow ill have some real figures, my guess is 9200 with an 18x8 jxf, lets see if im on the money. My FG33R3 now has 6x the original intake area so im expecting some decent numbers.
It starts and idles fine but it was 11 pm so I couldn't give it a hiding, tomorrow ill have some real figures, my guess is 9200 with an 18x8 jxf, lets see if im on the money. My FG33R3 now has 6x the original intake area so im expecting some decent numbers.
06-25-2014, 06:29 AM
#117
Senior Member
I had emailed Ray English about this and he suggested that a bigger carby would make the fg33r3 unresponsive, well tonight we started my engine with a Zama 16 43p (8.2mm venturi x16 mm bore) with a robart air tank with a regulator feeding 4psi air pressure to my fuel tank to pump fuel through the carby.
The performance is truly night and day, the exhaust note is so different even my wife noticed, its aggressive at idle lumping 2 cylinders at a time, the progression is better than it has ever been, no miss,pop or hesitation just real performance, it really hammers! 8920rpm turning a 18x6! It
could only muster 8120 rpm 3 days ago with a custom inlet manifold and exhaust.
I've seen much talk about inlets and exhausts but I have now seen how much hp Saito's rubbish carby is robbing from this motor.
Video coming asap.
I'm going to increase the alcohol carburetor size from the stock FA-450R3's 9.7mm to the optional FA-220 Big Bore 12mm carburetor. That will increase the cross sectional area by over 50%. On a 12.8:1 CR FA-180 running on CDI, the 12mm carburetor on a ported intake manifold was good for 8450 RPM compared to 8050 RPM for the stock 11mm FA-180 carburetor. I would think the power gains from a 12.2:1 compression ratio FA-512R3 (high compression methanol version of the FG-84R3) would be even more pronounced.
06-25-2014, 06:48 AM
#118
Ok the mods are done, custom ported manifold,custom inlet with 16 x 12.7mm walbro carby.
It starts and idles fine but it was 11 pm so I couldn't give it a hiding, tomorrow ill have some real figures, my guess is 9200 with an 18x8 jxf, lets see if im on the money. My FG33R3 now has 6x the original intake area so im expecting some decent numbers.
It starts and idles fine but it was 11 pm so I couldn't give it a hiding, tomorrow ill have some real figures, my guess is 9200 with an 18x8 jxf, lets see if im on the money. My FG33R3 now has 6x the original intake area so im expecting some decent numbers.
Please include sound (if possible) with your performance #'s.
Cheers
06-25-2014, 02:25 PM
#121
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
Tonight's tuning found the limit of carby size that this motor can tolerate, a Walbro WT 257 is too big(16 mm bore, 12.7 mm venturi).
It idles fine and progresses to 1/3 throttle before fuel flow becomes an issue, it required 10psi of fuel pressure to hit high rpm, it did however rev over 9000 revs. I will investigate the pop of pressure before I make a final decisions about the walbro.
I have returned to the zama carby at 14mm bore with 8mm venturi, I believe a 9.5mm venturi would work well and will look to get one when I find one.
At tonights end the carby was playing up, its original and 20 years old and I believe the adiaphragm has developed an issue but it was going well till it went out of tune.
It idles fine and progresses to 1/3 throttle before fuel flow becomes an issue, it required 10psi of fuel pressure to hit high rpm, it did however rev over 9000 revs. I will investigate the pop of pressure before I make a final decisions about the walbro.
I have returned to the zama carby at 14mm bore with 8mm venturi, I believe a 9.5mm venturi would work well and will look to get one when I find one.
At tonights end the carby was playing up, its original and 20 years old and I believe the adiaphragm has developed an issue but it was going well till it went out of tune.
Last edited by Blair K.; 06-26-2014 at 03:10 AM.
07-06-2014, 02:57 AM
#122
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
Hi Guys, today I took the p-47 to the field for the first time since the mods, in its list of mods it now has a custom 1/2" exhaust that has been fully heat wrapped, it has a Zama C1U carby with 14mm throat with 8mm venturi , it has a 6 volt electric fuel pump running on 2 cell 2.4volt pack with a return circuit and a metering valve so I can dial in 2.5psi to 11 psi Fuel delivery, it has a custom inlet manifold that is ported and has all corners rounded, it also has a 8.3mm primary inlet tube instead of 7mm standard, the result is 7.1 kg of thrust with jxf 18x6(5.0 kg stock).
She sounds so very angry and many comment on its presence, it noise tests at 95.9db at 3.0 M so I only just made it in on 96db cut off.
A new problem now presented itself, I cant get enough intake air into the engine with engine cowl on, it makes great hp and holds good tune but as soon as the engine cowl is installed it cant breath enough clean air so custom air intake is needed.
She sounds so very angry and many comment on its presence, it noise tests at 95.9db at 3.0 M so I only just made it in on 96db cut off.
A new problem now presented itself, I cant get enough intake air into the engine with engine cowl on, it makes great hp and holds good tune but as soon as the engine cowl is installed it cant breath enough clean air so custom air intake is needed.
07-09-2014, 04:24 AM
#124
Senior Member
Join Date: Apr 2014
Location: Brisbane, Australia
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
Ok my cold air intake is almost done, ill TIG the ally tube on tomorrow and cut it to 125mm long and start fitting it for the warbirds day this Sunday.
It took some hours this week but im sure it will solve my air flow issues.
It took some hours this week but im sure it will solve my air flow issues.