Final stage wheel indentations P120
09-30-2005, 03:00 PM
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Final stage wheel indentations P120
Hi,
I have a P120 and I recently removed the rear exhaust cone from the engine to clean it. I noticed that on the final stage wheel (the last turning wheel in the engine) that there are some gouges close the the center of the hub. Not right next the hub but right on the section of the wheel where there is a raised lip that goes around the circumference. Im not sure if these are there due to a defect of is it is part of the balancing process of the wheel. It kinda looks as if someone took a dremel with a drum sander on it and shaved a bit here and there. Can you telll me if this is normal? The engine runs fine, never had any problems with its operation. Also what is the normal expected spool up time of a p120 from idle to max power?
Thank you for any info
I have a P120 and I recently removed the rear exhaust cone from the engine to clean it. I noticed that on the final stage wheel (the last turning wheel in the engine) that there are some gouges close the the center of the hub. Not right next the hub but right on the section of the wheel where there is a raised lip that goes around the circumference. Im not sure if these are there due to a defect of is it is part of the balancing process of the wheel. It kinda looks as if someone took a dremel with a drum sander on it and shaved a bit here and there. Can you telll me if this is normal? The engine runs fine, never had any problems with its operation. Also what is the normal expected spool up time of a p120 from idle to max power?
Thank you for any info
09-30-2005, 10:27 PM
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RE: Final stage wheel indentations P120
Hi,
Yes those marks are for balancing, and the raised ring you refer to is the sacrificial balancing ring, cast in just for balancing.
Throttle up times are tricky to figure, as the ECU/GSU averages values with a time constant that can make all of the readings 1 second older than they appear. Also, on a JetCat a very careful control loop is used that makes sure the RPM does not overshoot. The sum of these facts is that using the GSU and the RPM reading is not too useful to measure response times.
Bob can measure it on a thrust stand, and I would say typical P-120 times are around 3.5 seconds from just above idle to rated thrust.
Yes those marks are for balancing, and the raised ring you refer to is the sacrificial balancing ring, cast in just for balancing.
Throttle up times are tricky to figure, as the ECU/GSU averages values with a time constant that can make all of the readings 1 second older than they appear. Also, on a JetCat a very careful control loop is used that makes sure the RPM does not overshoot. The sum of these facts is that using the GSU and the RPM reading is not too useful to measure response times.
Bob can measure it on a thrust stand, and I would say typical P-120 times are around 3.5 seconds from just above idle to rated thrust.
10-01-2005, 10:48 AM
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RE: Final stage wheel indentations P120
Hey Matt,
Thanks for the prompt reply. I kinda figured that that's what it was..............but i wanted to be sure that the engine wasn't self destructing.....he he. 3.5 seconds sounds about right from what I have experienced. I was a little curious because I read a previous thread stating that there may be an issue with the positioning of the temp probe, but it all looks to be normal. Its a great running engine and very easy to use. It is a good product and worth every penny. Take care.........
Thanks for the prompt reply. I kinda figured that that's what it was..............but i wanted to be sure that the engine wasn't self destructing.....he he. 3.5 seconds sounds about right from what I have experienced. I was a little curious because I read a previous thread stating that there may be an issue with the positioning of the temp probe, but it all looks to be normal. Its a great running engine and very easy to use. It is a good product and worth every penny. Take care.........
11-27-2005, 10:46 AM
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RE: Final stage wheel indentations P120
Hello Matt, I have just started out with my first P120 Jetcat, does it matter which gas I use, is it best to use Propane or Butane. Cheers, Collin
11-27-2005, 11:26 AM
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RE: Final stage wheel indentations P120
Hi Colin
Matt I am sure will not mind me inputing
You need propane/ butane mix it is 50/50%
B&Q sell it here in the uk under the brand name Gosystem
Ian
Matt I am sure will not mind me inputing
You need propane/ butane mix it is 50/50%
B&Q sell it here in the uk under the brand name Gosystem
Ian
