Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

A Ram750 Plus Air Start with 18 volt blower?

Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

A Ram750 Plus Air Start with 18 volt blower?

Old 12-14-2004, 12:45 PM
  #26  
rhklenke
My Feedback: (24)
 
rhklenke's Avatar
 
Join Date: Jun 2002
Location: Richmond, VA
Posts: 5,997
Likes: 0
Received 33 Likes on 20 Posts
Default RE: A Ram750 Plus Air Start with 18 volt blower?

ORIGINAL: unknown

I think for an external engine setup like the hotspot or kangaroo jets it would be OK to use a blower. But for an internal engine setup. the blower would have to be too close to the compressor to be effective and god forbid the compressor stop turning during startup the fuel pump will still pumps fuel to the stall burning engine. Its very dangerous.
Sorry, but this is spoken like a man who doesn't know what he's talking about. You should perhaps stick to talking about what you know about - whatever that may be. The ECU WILL NOT pump fuel into the engine unless the RPM is high enough to start AND the EGT indicates that the propane is still burning. If EITHER of these measurments go below limits, the ECU shuts off the fuel pump, and as Tom mentioned above, if you're using a blower, and you get a wet start (which is not any more likely than starting with air) it will simply blow the flames out the tailpipe until the small bit of fuel that was spilt is consumed.

I have seen and started AMT's with blowers dozens of times and it works quite well, is easy if you know how to start the turbine in the first place, and does NOT produce wet starts on any that I have seen or done. The only two variables are will the blower spin the turbine to a high enough RPM, and will the propane delivery system being used keep the propane mixture rich enough to stay lit until the kero starts (if it can't, the propane will simply blow out because of the somewhat higher airflow and the start sequence just halts - no excess (or any) kero in the engine).

I agree with the others that the most straight-forward way to start the turbine is with an external air source, especially for someone new to turbines, but I'd bet that someone familiar with starting an air start turbine could start a RAM with a blower quite easily.
Old 12-14-2004, 02:37 PM
  #27  
unknown
Senior Member
 
Join Date: Aug 2002
Location: Orlando, FL
Posts: 675
Likes: 0
Received 0 Likes on 0 Posts
Default RE: A Ram750 Plus Air Start with 18 volt blower?

Sorry, but this is spoken like a man who doesn't know what he's talking about. You should perhaps stick to talking about what you know about - whatever that may be. The ECU WILL NOT pump fuel into the engine unless the RPM is high enough to start AND the EGT indicates that the propane is still burning. If EITHER of these measurments go below limits, the ECU shuts off the fuel pump, and as Tom mentioned above, if you're using a blower, and you get a wet start (which is not any more likely than starting with air) it will simply blow the flames out the tailpipe until the small bit of fuel that was spilt is consumed.
We all knows what a ECU suppose to do. But thats not the case some time with the Electrodynamics ECU. Starting a turbine by blowing air into the inlet of a jet is not the same as blowing it directly in front the engine itself.

You should perhaps stick to talking about what you know about - whatever that may be
I know what i'm taking about do you???

Steve you are doing the right thing getting your scuba tank.
Old 12-14-2004, 05:25 PM
  #28  
rhklenke
My Feedback: (24)
 
rhklenke's Avatar
 
Join Date: Jun 2002
Location: Richmond, VA
Posts: 5,997
Likes: 0
Received 33 Likes on 20 Posts
Default RE: A Ram750 Plus Air Start with 18 volt blower?

ORIGINAL: unknown

We all knows what a ECU suppose to do. But thats not the case some time with the Electrodynamics ECU. Starting a turbine by blowing air into the inlet of a jet is not the same as blowing it directly in front the engine itself.
Why don't you show us what you '"knows" by 'splaning us to the difference? The ECU has NO IDEA how the turbine is being spun, only what RPM it is turning and what the EGT is. If both are within limits - which can be easily done with a proper blower - the engine will start fine.

I know what i'm taking about do you???

Steve you are doing the right thing getting your scuba tank.
I think starting with the scuba tank is easier, so that's what he should do. My issue is with your comment that starting with a blower is "very dangerous" and your logic for saying so - both are wrong.
Old 12-15-2004, 08:45 AM
  #29  
unknown
Senior Member
 
Join Date: Aug 2002
Location: Orlando, FL
Posts: 675
Likes: 0
Received 0 Likes on 0 Posts
Default RE: A Ram750 Plus Air Start with 18 volt blower?

Why don't you show us what you '"knows" by 'splaning us to the difference? The ECU has NO IDEA how the turbine is being spun, only what RPM it is turning and what the EGT is. If both are within limits - which can be easily done with a proper blower - the engine will start fine.

If i'm correct Steve is using the C/P pressure controlled ECU. I ("knows") this because I was once a proud owner of a AIR START RAM 1000 and 750 engine. This does not happen all the time but every so often during a fail start, the fuel pump will still continue to pump fuel into the hot engine before timing out. Unplug the ecu battery pack and you will be OK. I used everything possible to start my engine (keyboard duster, shop vacuum, home vacuum cleaner, "been there, done that" before getting the airtank. The problem with using low air pressure to start a engine is after ignition the engine RPM sometimes slows because of high temperature (NOT ENOUGH RPM TO COOL ENGINE DURING STARTUP). This causes the engine's RPM to slow down because of excessive heat on the BEARING causing the engine to stop turning.

Before the fuel pump time out, your jet is on fire.
Old 12-15-2004, 10:30 AM
  #30  
rhklenke
My Feedback: (24)
 
rhklenke's Avatar
 
Join Date: Jun 2002
Location: Richmond, VA
Posts: 5,997
Likes: 0
Received 33 Likes on 20 Posts
Default RE: A Ram750 Plus Air Start with 18 volt blower?

ORIGINAL: unknown

[snip]
I used everything possible to start my engine (keyboard duster, shop vacuum, home vacuum cleaner, "been there, done that" before getting the airtank. The problem with using low air pressure to start a engine is after ignition the engine RPM sometimes slows because of high temperature (NOT ENOUGH RPM TO COOL ENGINE DURING STARTUP). This causes the engine's RPM to slow down because of excessive heat on the BEARING causing the engine to stop turning.

Before the fuel pump time out, your jet is on fire.
Ah, notice that I said a "proper" blower. Vacuum cleaners are not "proper" blowers. You need one that is capable of spinning the turbine to the same RPM as the high pressure air can - typically 5K to 6K or more. If you use a blower of this capacity, the internal turbine temps will actually be lower than with high pressure air because it take more airflow from a blower to turn this RPM than doing it with high pressure air - been there, seen that...

Bob
Old 12-15-2004, 12:40 PM
  #31  
MMallory
My Feedback: (1)
 
Join Date: Dec 2001
Location: South Plainfield, NJ
Posts: 1,149
Likes: 0
Received 0 Likes on 0 Posts
Default RE: A Ram750 Plus Air Start with 18 volt blower?

Steve,

Just send the RAM to me and get proper auto-start. Stop causing trouble.

BTW, I will pay for shipping,[sm=lol.gif]

Mark M.
Old 12-15-2004, 08:10 PM
  #32  
Steve S
Senior Member
Thread Starter
My Feedback: (54)
 
Join Date: Oct 2003
Location: Va Beach, VA
Posts: 1,086
Likes: 0
Received 0 Likes on 0 Posts
Default RE: A Ram750 Plus Air Start with 18 volt blower?

Mark

LOL Good one man!! I love Christmas & I am totally in the holiday spirit but I'm not feeling quite that generous !! Never hurts to ask tho huh? LOL

I got my Pony Scuba tanks today so I 'll be all set for the maiden after the holidays,wish me luck [8D]

Merry Xmas guys!!!


Steve

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.