VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #21  
Old 03-19-2017, 08:18 AM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 7,237
Default

Quote:
Originally Posted by CubedRoot View Post
Hmm... For some reason I thought they dyno'd all their engines before they sent them out.
Not everyone operates a dynamometer. Most small aircraft engines get run on a simple test stand with a calibrated club prop. The point is to run it and look at temperatures, pressures, etc, not tune for max HP. If it will reach a given RPM while turning the club designated for that engine model, it is assumed to make rated power.

The photo above (post 12) is a test stand. Below is the test stand currently in use at Continental Mattituck:



Barrett, Lycon, and Sky Dynamics all run dynos, but they're all different.

Barrett runs flat motors on an old school Kahn shaft drive water pump. When installed many moons ago, I'm pretty sure it was the first at an independent shop.

Barrett M-14s go on a torque reaction stand, in which the entire engine and mount can rotate on a very large central spindle. The rotation is constrained by a load cell on an arm, which converts strain to an electrical signal. Engine load is a constant speed prop.

Lycon appears to run flat motors on a similar torque reaction rig using a constant speed prop. Sky Dynamics has two torque reaction rigs, with load provided by a shaft driven oil pump.

I'm not sure where Titan's dyno is right now. It was AWOL from the new Fairhope facility when I visited in November. I'll check again next week.

Anyway, don't assume your HP was actually measured. And even when it is, all dynos are not the same.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
Reply With Quote
  #22  
Old 03-19-2017, 08:48 AM
rv6ejguy's Avatar
rv6ejguy rv6ejguy is offline
 
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 4,069
Default

Aerosport has two mobile test rigs and their dyno is currently under construction. All engines get run in and checked on the test rigs with props or clubs.
__________________

Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW- 417.4 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm


Reply With Quote
  #23  
Old 03-20-2017, 06:15 PM
CubedRoot's Avatar
CubedRoot CubedRoot is offline
 
Join Date: Sep 2013
Location: Ooltewah, TN.
Posts: 435
Default

Quote:
Originally Posted by DanH View Post
Not everyone operates a dynamometer. Most small aircraft engines get run on a simple test stand with a calibrated club prop. The point is to run it and look at temperatures, pressures, etc, not tune for max HP. If it will reach a given RPM while turning the club designated for that engine model, it is assumed to make rated power.

The photo above (post 12) is a test stand. Below is the test stand currently in use at Continental Mattituck:


Barrett, Lycon, and Sky Dynamics all run dynos, but they're all different.

Barrett runs flat motors on an old school Kahn shaft drive water pump. When installed many moons ago, I'm pretty sure it was the first at an independent shop.

Barrett M-14s go on a torque reaction stand, in which the entire engine and mount can rotate on a very large central spindle. The rotation is constrained by a load cell on an arm, which converts strain to an electrical signal. Engine load is a constant speed prop.

Lycon appears to run flat motors on a similar torque reaction rig using a constant speed prop. Sky Dynamics has two torque reaction rigs, with load provided by a shaft driven oil pump.

I'm not sure where Titan's dyno is right now. It was AWOL from the new Fairhope facility when I visited in November. I'll check again next week.

Anyway, don't assume your HP was actually measured. And even when it is, all dynos are not the same.
Thanks for the info Dan. I am still several years out before I make an engine decision, so I haven't studied up a whole lot on them yet. So many choices out there makes research a little tricky for someone as new to homebuiding as me.

I have decided that wherever I get the engine from, I am hoping they do the "build school" type sessions, that let an owner participate in some way in the engine build.

I had assumed that Aerosport had a dyno since they "rate" thier engines..but what you said makes sense.
__________________
Lynn Dixon
RV-7 Slider -
Tail kit Completed - March 2017
Wing Kit Started - June 2017
My Build Log: http://www.theskunkwerx.com

VAF Donation paid for 2017
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 04:35 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.