VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #21  
Old 07-14-2018, 01:11 PM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,122
Default

Quote:
Originally Posted by Dustyone View Post
?..Michael, David and I will probably have a head to head comparison after I sort out my gami spread/induction leak issue some time in the future.

It should also be noted that I also have an exposed A/C Condenser pod mounted on the belly of my aircraft and what difference that makes,I am not sure,but the data point should be recognised that there are very few identical RV-10's to compare with...

OK. The fact that you are dragging around the AC condenser and you still return the same speed and FF as David is a testament to the efficiency of the SDS ignition. In that respect, a single test of your bird with the "magneto timing" of 23 degrees (or whatever your engine was certified with) compared to the "optimum" timing (as described to Bill above) will tell the tale. Like I said, I'm predicting a +10 knot advantage with the SDS timing optimized.

And yes, grab the SDS intake tube kit. That will solve your leaks.
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
Reply With Quote
  #22  
Old 07-14-2018, 01:14 PM
rv6ejguy's Avatar
rv6ejguy rv6ejguy is offline
 
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 4,851
Default

Quote:
Originally Posted by RV10inOz View Post
And another data point, I fly with two mags. My GAMI spread is good. A friend with the dual SDS ignition system in his RV10, flies the same speed and fuel flow. His GAMI spread is not quite as good, so maybe he gets and advantage there with the sub-optimal set up. Be interesting to see when we get that sorted.

Chev Vs ford......... YMMV too.
Will be interesting to see how things compare once your friend gets his GAMI spread the same as yours.

Pretty well everyone with EI, reports 1+ GPH less than they had with mags running high and LOP.

Same engine, manifold, CR, prop etc? One plane dirtier/ heavier than the other? I don't see how it's possible for fixed timing to make the same power as optimally advanced timing while running LOP. The flame speed is around 30% slower running 16.5-17AFR than 12.5 ish where best power is made and the mag timing is optimized for.
__________________

Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW since 2003- 426.1 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm



Last edited by rv6ejguy : 07-14-2018 at 03:23 PM.
Reply With Quote
  #23  
Old 07-14-2018, 02:22 PM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,122
Default

Quote:
Originally Posted by rv6ejguy View Post
...I don't see how it's possible for fixed timing to make the same power as optimally advanced timing while running LOP. The flame speed is around 30% slower running 16.5-17AFR than 12.5 ish where best power is made and the mag timing is optimized for.
Yep, this threw me for a loop too. NO WAY an ignition timing of 23 degrees (magnetos) will deliver the same speed as an EI with optimized timing LOP. No way. However, the big difference here is the added drag of the AC condenser, I'd think. That's your smoking gun.
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
Reply With Quote
  #24  
Old 07-14-2018, 02:49 PM
N941WR's Avatar
N941WR N941WR is offline
 
Join Date: Jan 2005
Location: SC
Posts: 11,706
Default

You don't always need fuel injection to get good spreads.
This picture was taken in my carbureted O-360 running dual P-mags with an unaltered"A curve" AKA "Jumper in".

__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
Reply With Quote
  #25  
Old 07-14-2018, 03:31 PM
rv6ejguy's Avatar
rv6ejguy rv6ejguy is offline
 
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 4,851
Default

Good numbers indeed Bill. Me thinks that -9 wing works better than the 6,7,8 wing does up there.
__________________

Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW since 2003- 426.1 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm


Reply With Quote
  #26  
Old 07-14-2018, 04:19 PM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,122
Default

Quote:
Originally Posted by N941WR View Post
You don't always need fuel injection to get good spreads.
This picture was taken in my carbureted O-360 running dual P-mags with an unaltered"A curve" AKA "Jumper in"...
Thats an enviously tight EGT spread. Now go out and find the peak ignition timing and report back with your optimized cruise numbers.
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
Reply With Quote
  #27  
Old 07-14-2018, 05:26 PM
N941WR's Avatar
N941WR N941WR is offline
 
Join Date: Jan 2005
Location: SC
Posts: 11,706
Default

Quote:
Originally Posted by rv6ejguy View Post
Good numbers indeed Bill. Me thinks that -9 wing works better than the 6,7,8 wing does up there.
Absolutely! The -9 wing is stunning. What gets me is that even at that altitude, I was still trimmed nose down. Whereas the short wing RV's are trimmed nose up starting at around 8 to 9 K and above. With the O-360 she stalls in the mid 40's and will cruise right at 200 mph, if I want to put the fuel through her.

About my EGT spread, I have done nothing special to this engine, other than assemble it from an ECi kit. Stock crossover exhaust but it does have a unique FAB of my own design that was required due to the Sam James cowl. I might have just gotten lucky.

Quote:
Originally Posted by Toobuilder View Post
Thats an enviously tight EGT spread. Now go out and find the peak ignition timing and report back with your optimized cruise numbers.
Give me a call, let's get together at OSH. I am going for a short flight but probably won't fly until after we get back.
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
Reply With Quote
  #28  
Old 07-15-2018, 04:48 PM
Toobuilder's Avatar
Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,122
Default

Quote:
Originally Posted by N941WR View Post
...Give me a call, let's get together at OSH. I am going for a short flight but probably won't fly until after we get back.
No OSH for me this year again - otherwise I'd certainly give you a shout. We're just scratching the surface on optimum timing for these engines, so we definitely need more people out there doing methodical flight test. Go get some data and we'll put our heads together.
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
Reply With Quote
  #29  
Old 07-15-2018, 06:02 PM
RV10inOz's Avatar
RV10inOz RV10inOz is offline
 
Join Date: May 2008
Location: Brisbane Qld. Aust.
Posts: 2,131
Default

Quote:
Originally Posted by rv6ejguy View Post
Will be interesting to see how things compare once your friend gets his GAMI spread the same as yours.

Pretty well everyone with EI, reports 1+ GPH less than they had with mags running high and LOP.

Same engine, manifold, CR, prop etc? One plane dirtier/ heavier than the other? I don't see how it's possible for fixed timing to make the same power as optimally advanced timing while running LOP. The flame speed is around 30% slower running 16.5-17AFR than 12.5 ish where best power is made and the mag timing is optimized for.
He needs the upper deck pressured due to ram air effect.

He is coming to see you shortly (AM)

Up high with lean mixtures advance will help, you and I know that, just needs the upper deck turbo style system.
__________________
______________________________

David Brown


The two best investments you can make, by any financial test, an EMS and APS!
Reply With Quote
  #30  
Old 07-16-2018, 09:02 AM
rv6ejguy's Avatar
rv6ejguy rv6ejguy is offline
 
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 4,851
Default

Yes, looking forward to meeting Ashley here soon and show him the operation and some of the local SDS installs. He's been a super helpful and friendly guy to deal with as have most of our other Aussie customers.

I'm hoping to make a trip down under in 2019 to check out the aviation scene there and in NZ.
__________________

Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, SDS EFI, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW since 2003- 426.1 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm


Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 09:57 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.