VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #31  
Old 06-15-2014, 11:28 PM
SHIPCHIEF SHIPCHIEF is offline
 
Join Date: Mar 2008
Location: Seattle
Posts: 1,412
Default

Bob;
Thanks for the pic. Could you fill us in on the engine details, so we can objectively compare that spark plug?
What is your engine's displacement, compression ratio, and what cylinder head temp do you usually run? Do you tend to run near full power (I do ) or idle around to save gas?
These would be the most important factors I can think of.
If you have 8.5:1 and run cylinder temps of 380F, a 7:1 engine that runs 320F Cylinder temps might be fine with the plug you show.
I am trying Autolite 386 plugs (on a P-mag), as Smokeyray had been using. That's an 18mm resistor plug. I have an O-290 with 7:1 compression and run cylinder temps of 320F most of the time (in my T-18). Perhaps any O-320, O-360 or O-540 with 7:1 pistons could use these 'hotter' Denso L14-U or Autolite 386 plugs.
The higher compression engines would need a colder plug than the one you show, and that's tough to find in an automotive 18mm resistor plug. These might require the cooler NGK BRE8ES, or other 14mm plugs and the adapters.
__________________
Scott Emery
http://gallery.eaa326.org/v/members/semery/
EAA 668340, chapter 326 & IAC chapter 67
RV-8 N89SE first flight 12/26/2013
Yak55M, and the wife has an RV-4
There is nothing-absolute nothing-half so much worth doing as simply messing around with Aeroplanes
(with apologies to Ratty)
2019
Reply With Quote
  #32  
Old 06-16-2014, 06:57 AM
rocketbob's Avatar
rocketbob rocketbob is offline
 
Join Date: Jun 2006
Location: 8I3
Posts: 3,564
Default

Stock O-360. They're still doing ok.

Years ago I ran the Autolite 386's in my stock 360 and found the electrodes would start rounding off. Not seeing that with L14's.

I have had very good luck with BR9ES/adapters.
__________________

Please don't PM me! Email only!

Bob Japundza CFI A&PIA
N9187P PA-24-260B Comanche, flying
N678X F1 Rocket, under const.
N244BJ RV-6 "victim of SNF tornado" 1200+ hrs, rebuilding
N8155F C150 flying
N7925P PA-24-250 Comanche, restoring
Not a thing I own is stock.
Reply With Quote
  #33  
Old 06-16-2014, 09:39 AM
Mike H Mike H is offline
 
Join Date: May 2014
Location: Savannah
Posts: 806
Default

The PMag adaptors are crack/failure prone. Check out the naval brass adaptors EFII sells. I have not tried these brass adaptors yet, but I will be installing some on an airplane I maintain.
Reply With Quote
  #34  
Old 06-16-2014, 09:53 AM
walkman's Avatar
walkman walkman is offline
 
Join Date: Oct 2011
Location: Atlanta
Posts: 878
Default

Quote:
Originally Posted by Mike H View Post
The PMag adaptors are crack/failure prone. Check out the naval brass adaptors EFII sells. I have not tried these brass adaptors yet, but I will be installing some on an airplane I maintain.
As far as adapters go, they are the bees knees.
__________________
RV-8 IO-360 (Bought)
RV-6 O-360 C/S (Sold)
Walkman aka Flame Out
Reply With Quote
  #35  
Old 06-16-2014, 12:14 PM
rocketbob's Avatar
rocketbob rocketbob is offline
 
Join Date: Jun 2006
Location: 8I3
Posts: 3,564
Default

More specifically the adapters that are machined out of aluminum bronze are better.
__________________

Please don't PM me! Email only!

Bob Japundza CFI A&PIA
N9187P PA-24-260B Comanche, flying
N678X F1 Rocket, under const.
N244BJ RV-6 "victim of SNF tornado" 1200+ hrs, rebuilding
N8155F C150 flying
N7925P PA-24-250 Comanche, restoring
Not a thing I own is stock.
Reply With Quote
  #36  
Old 06-16-2014, 03:17 PM
rcpaisley's Avatar
rcpaisley rcpaisley is offline
 
Join Date: Jan 2008
Location: Upland, CA
Posts: 286
Default bronze vs brass

Aluminum bronze is a more brittle alloy. Naval brass has more malleability - better toughness.

We make our adapters in house on our Conquest 42 lathe. That's why we can afford to make them the best they can be In fact, we make all our mechanical parts in house. This is invaluable in achieving high quality, rapid product design and evolution, and providing the best parts possible.

In fact, we're running some spark plug adapters right now (pic below)
Robert

__________________
EFII www.flyefii.com
Protek Performance

Last edited by rcpaisley : 06-16-2014 at 03:34 PM.
Reply With Quote
  #37  
Old 07-28-2014, 01:26 PM
Randy Randy is offline
 
Join Date: Jan 2005
Location: Sedona Arizona
Posts: 349
Default

Quote:
Originally Posted by digidocs View Post
Bob,

Are those plugs really as hot as this chart would seem to imply?



Thanks,
David
I did not see a reply on this important question regarding heat range of the various auto plug options that eliminate the adapters. From the chart above it appears that the Denso 14s are several steps hotter than the NGKk 8s.

Regardless of the successful use of the adapters by a number of people, I really do not want to add an extra set of threads into my combustion chambers.

I have researched heat ranges of the various plugs but have had a hard time finding a comparison of the auto plugs with the aviation variety.

Are the Autolite 386 plugs the same basic heat range as the Denso L-14U? And are they both essentially the same heat range as the NGK BR8ES plugs?

Randall, about to order Pmags...
Reply With Quote
  #38  
Old 07-12-2015, 04:09 PM
Ghost two-six's Avatar
Ghost two-six Ghost two-six is offline
 
Join Date: Apr 2015
Location: Sunny Florida
Posts: 26
Default Sit rep

Guys,
It's been a little while, how have the auto plugs been holding up ?
Any issues with these plugs fouling due to avgas ?
__________________
Save Money - Outsource Congress !!!
Reply With Quote
  #39  
Old 07-13-2015, 06:15 AM
mike newall's Avatar
mike newall mike newall is offline
 
Join Date: Jan 2005
Location: Yorkshire, England
Posts: 2,052
Default

150 hours on a split install.

2 P-Mags with Tempest on bottom and NGK BR9-EIX Iridium (part No 3981) - CHT's ran a little high, but all was well.

Plugs installed as per Brad's instructions with no problems.

After 150 hours, we changed a few things.

New lower harness, swapped the airplane plugs for more NGK's, re timed the motor and had a good seal around the plenum. I know, we changed more than one thing, however, the CHT's came down by 50f !

We now have around 300 hours on the motor

TMX IO-360, 2 P-Mags, MT 3 blade c/s prop.

All well, temps great, plugs show no fouling on avgas, we get them either at O'Reilly's or Amazon for around $6 each. Swap them twice a year.
__________________
"I add a little excitement, a little spice to your lives, and all you do is complain!" - Q

Donated in 2020
Reply With Quote
  #40  
Old 07-13-2015, 08:39 AM
jbDC9 jbDC9 is offline
 
Join Date: Jan 2005
Location: Houston, TX
Posts: 868
Default

Quote:
Originally Posted by Ghost two-six View Post
.... how have the auto plugs been holding up ?
Any issues with these plugs fouling due to avgas ?
I've been running dual Pmags with NGK BR8ES plugs on my RV-8 since day one; currently at 1150 hours and have had zero problems with the plugs. I run a mix of mogas (maybe 25%) in with 100LL, but have never had a fouled plug. I usually run a set of plugs for some 150-ish hours before replacement, which sets me back a whopping 2-3 bucks each at Autozone... nice.
__________________
John Bixby
RV-8 QB sn 82030 - 1750 hrs
O-360-A1D/CS/Pmags
Houston, TX
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 03:13 AM.


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.