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jumpstarting a Rocket

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jrstone(at)insightbb.com
Guest

Posted: Sun Sep 30, 2007 6:17 pm Post subject: jumpstarting a Rocket

Does anyone know of a product that allows one to  jumpstart a Rocket when the battery has run down?

  

 I have 10 to 1 pistons and after flying for a  while, getting gas, I am unable to start due to very high resistance to cranking  caused, I assume by the hot engine.   After cooling for 2 hours or so,  she turns easy and starts right up.  I thought the problem was with the  P680s being 4-5 years old so I replaced them.  No improvement to the  problem.  All suggestions welcome.

 TIA,

 Jim Stone

  

  [quote][b]

T.gummo(at)verizon.net
Guest

Posted: Sun Sep 30, 2007 7:52 pm Post subject: jumpstarting a Rocket

My normal piston IO-540 J4A5 turns over very easily once  it is hot.  So, I don't have a clue.

  

 Tom Gummo

Apple Valley, CA

Harmon  Rocket-II

 N561FS    350 hours - still  smiling

 do not archive

  

 http://mysite.verizon.net/t.gummo/index.html



 [quote]   ---

nico(at)cybersuperstore.c
Guest

Posted: Sun Sep 30, 2007 9:51 pm Post subject: jumpstarting a Rocket

Are you sure you don’t have a hydrostatic lock?  

   

         

  

From: owner-rocket-list-server(at)matronics.com [mailto:owner-rocket-list-server(at)matronics.com] On Behalf Of Jim Stone

 Sent: Sunday, September 30, 2007 7:16 PM

 To: rocket-list(at)matronics.com

 Subject: jumpstarting a Rocket  

  

     

Does anyone know of a product that allows one to jumpstart a Rocket when the battery has run down?  

    

   

    

I have 10 to 1 pistons and after flying for a while, getting gas, I am unable to start due to very high resistance to cranking caused, I assume by the hot engine.   After cooling for 2 hours or so, she turns easy and starts right up.  I thought the problem was with the P680s being 4-5 years old so I replaced them.  No improvement to the problem.  All suggestions welcome.  

    

TIA,  

    

Jim Stone  

    

   

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       [quote][b]

fairlea(at)amtelecom.net
Guest

Posted: Mon Oct 01, 2007 3:10 am Post subject: jumpstarting a Rocket

Jim  

   

            Typically these engines turn over much easier hot than cold, especially with higher compression pistons. That has been my experience.  

Since you have eliminated the battery issue then check all big lead connections, especially ground connections.  Take the starter off and take it to your local automotive starter shop and have it checked out.  Also next time the engine is hot, be careful, and try to turn the prop by hand to see if there are any restrictions.  Hydrostatic lock is not usual in this type of engine but maybe there is something else going on in the engine itself.  

My bets are on the starter.  I have had two new skytec starters that have had to be replaced out of the last four airplanes.  The replacements have worked fine.  

   

   

   

Tom  

   

         

  

From: owner-rocket-list-server(at)matronics.com [mailto:owner-rocket-list-server(at)matronics.com] On Behalf Of Jim Stone

 Sent: September 30, 2007 10:16 PM

 To: rocket-list(at)matronics.com

 Subject: jumpstarting a Rocket  

  

     

Does anyone know of a product that allows one to jumpstart a Rocket when the battery has run down?  

    

   

    

I have 10 to 1 pistons and after flying for a while, getting gas, I am unable to start due to very high resistance to cranking caused, I assume by the hot engine.   After cooling for 2 hours or so, she turns easy and starts right up.  I thought the problem was with the P680s being 4-5 years old so I replaced them.  No improvement to the problem.  All suggestions welcome.  

    

TIA,  

    

Jim Stone  

    

   

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     Release Date: 29/09/2007 9:46 PM 

  29/09/2007 9:46 PM

      [quote][b]

rgraham(at)ozemail.com.au
Guest

Posted: Mon Oct 01, 2007 3:34 am Post subject: jumpstarting a Rocket

Jim,



Which starter motor do you have and is your engine to airframe earth 

connection good?



Cheers,

Ron Graham (F1 #105, Oz)

jrstone(at)insightbb.com
Guest

Posted: Mon Oct 01, 2007 4:59 am Post subject: jumpstarting a Rocket

Thanks for all the troubleshooting tips.  I'll  address each one here.

  

 I have the B&C starter, two new PC680  batteries, I used number two aircraft wire from battery to firewall for both Pos  and Neg., The Neg cable home runs to the forest of tabs on the firewall, then on  to engine block.

  

 I will check all grounds and positive connections  all the way to the starter, today and will report back.  

 As for Hydrostatic lock, I'm not sure how that  could be the problem unless a whole lot of fuel got into the cylinder, is that  reasonable? 

  

 My hot start symptom is: normal rotation and  some firing but no start, as I continue to crank, the high resistance wins over  the batteries and the cranking degrades to one or two blades before  stopping.  After cranking and no start, I feel like the engine is not  getting any fuel so I advance the mixture midway.  That is about the time  the battery is running down (hydrostatic lock?).

 As for hot start technique, I understand that full  throttle and mixture off with no prime is the general recommendation, however, I  have been cautioned about using that procedure in a Harmon Rocket because the  tail has come off the ground and scarred to poo out of the owner.  Any  comments here?

  

 I was hoping someone has come up with a simple  and permanent charging and jumpstart system where the battery cover would not  have to be removed/replaced.  I would like to avoid an external  opening type system as per Bob Nuckolls design.

  

 Thanks for al the help,

 If you would rather talk than type, call  anytime.  502 235-3599 or send my you number, I'll call you.

 [quote]   ---

nico(at)cybersuperstore.c
Guest

Posted: Mon Oct 01, 2007 7:29 am Post subject: jumpstarting a Rocket

Type is better, then I can read it when I have time.  

   

If the engine is turning over, hydrostatic lock is out of the question. Without trying to instruct you, hydrostatic locks ruined engines where one cylinder was flooded with more fuel than the compression chamber’s capacity and a cylinder earlier in the firing order fires first. There is no way that the fired-up engine can stop on the flooded cylinder and it usually bends the conrod. (and ruins plans for flying). If the engine turns through all cylinders, there is no hydrostatic lock.   

   

It is either flooded or fuel-starved, if the ignition is firing. For fuel injected Lyc hot-starts, I used to intentionally flood the engine and then crank it with fuel cut off and full throttle – but that was in a trike. The Rocket might well change position quickly with that technique.   

   

I would agree with the other folks that you may have to focus on the battery and the starter, to increase battery capacity and/or reduce starter load.   

   

Nico  

   

         

  

From: owner-rocket-list-server(at)matronics.com [mailto:owner-rocket-list-server(at)matronics.com] On Behalf Of Jim Stone

 Sent: Monday, October 01, 2007 5:59 AM

 To: rocket-list(at)matronics.com

 Subject: Re: Rocket-List: jumpstarting a Rocket  

  

     

Thanks for all the troubleshooting tips.  I'll address each one here.  

    

   

    

I have the B&C starter, two new PC680 batteries, I used number two aircraft wire from battery to firewall for both Pos and Neg., The Neg cable home runs to the forest of tabs on the firewall, then on to engine block.  

    

   

    

I will check all grounds and positive connections all the way to the starter, today and will report back.    

    

As for Hydrostatic lock, I'm not sure how that could be the problem unless a whole lot of fuel got into the cylinder, is that reasonable?   

    

   

    

My hot start symptom is: normal rotation and some firing but no start, as I continue to crank, the high resistance wins over the batteries and the cranking degrades to one or two blades before stopping.  After cranking and no start, I feel like the engine is not getting any fuel so I advance the mixture midway.  That is about the time the battery is running down (hydrostatic lock?).  

    

As for hot start technique, I understand that full throttle and mixture off with no prime is the general recommendation, however, I have been cautioned about using that procedure in a Harmon Rocket because the tail has come off the ground and scarred to poo out of the owner.  Any comments here?  

    

   

    

I was hoping someone has come up with a simple and permanent charging and jumpstart system where the battery cover would not have to be removed/replaced.  I would like to avoid an external opening type system as per Bob Nuckolls design.  

    

   

    

Thanks for al the help,  

    

If you would rather talk than type, call anytime.  502 235-3599 or send my you number, I'll call you.  

  [quote]    

---

russ(at)wernerworld.com
Guest

Posted: Mon Oct 01, 2007 7:51 am Post subject: jumpstarting a Rocket

Another thing that can cause a similar symptom is ignition  firing too early and hitting before TDC.  

  

  

  

 ---

nico(at)cybersuperstore.c
Guest

Posted: Mon Oct 01, 2007 8:12 am Post subject: jumpstarting a Rocket

I doubt it. An advanced ignition timing would cause the engine to kick-back and it would do the same after the cool-down period. But, apparently, it starts normally after cooling down. I believe the battery doesn’t have the capacity to crank the engine long (fast) enough to fire up during a hot start. I had a 500 Commander with suspicious batteries, and during hot starts it would easily exhaust the batteries capacity. One day a guy lifted his Centurion’s battery to give me a jump-start. The cranking was at least double the speed of my regular batteries and the engines fired up without any problems. I replaced the batteries and the problem went away immediately.   

   

Nico  

   

         

  

From: owner-rocket-list-server(at)matronics.com [mailto:owner-rocket-list-server(at)matronics.com] On Behalf Of Wernerworld

 Sent: Monday, October 01, 2007 8:52 AM

 To: rocket-list(at)matronics.com

 Subject: Re: Rocket-List: jumpstarting a Rocket  

  

     

Another thing that can cause a similar symptom is ignition firing too early and hitting before TDC.    

    

   

    

   

    

   

    

---

dlbenham(at)hughes.net
Guest

Posted: Mon Oct 01, 2007 8:47 am Post subject: jumpstarting a Rocket

Is hydrostatic lock the same as  hydraulic lock?  Inquiring minds want to know.

 Dallas Benham

 398DB

    [quote][b]

nico(at)cybersuperstore.c
Guest

Posted: Mon Oct 01, 2007 9:39 am Post subject: jumpstarting a Rocket

Apparently, they are the same.  

   

         

  

From: owner-rocket-list-server(at)matronics.com [mailto:owner-rocket-list-server(at)matronics.com] On Behalf Of dlbenham

 Sent: Monday, October 01, 2007 10:46 AM

 To: rocket-list(at)matronics.com

 Subject: Re: Rocket-List: jumpstarting a Rocket  

  

     

Is hydrostatic lock the same as hydraulic lock?  Inquiring minds want to know.  

    

Dallas Benham  

    

398DB  

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jrstone(at)insightbb.com
Guest

Posted: Mon Oct 01, 2007 5:19 pm Post subject: jumpstarting a Rocket

I retarded both the mag and the Electronic ignition  to 20 deg today.  I'll fly it tomorrow a.m. and will report  back.

 [quote]   ---

russ(at)wernerworld.com
Guest

Posted: Mon Oct 01, 2007 5:48 pm Post subject: jumpstarting a Rocket

The timing to check is the one while cranking.  Usually  it is set to TDC.  I just replaced a mag and switched to a model that  starts at 5 ATDC and runs at 25 deg.

  

 Russ

  

  

 ---

jrstone(at)insightbb.com
Guest

Posted: Mon Oct 01, 2007 6:35 pm Post subject: jumpstarting a Rocket

The impulse coupler on my slick mag fires at 25 deg  prior to what ever you have it set at during start.  So at 20  deg normal position, during start it should fire at 5 deg ATDC, like  your new one.  I'm thinking this will help with the battery drain problem  during a hot start.

 Jim

 [quote]   ---

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