Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


Why the slanted glow plug on some Fox engines? Babe_b10
Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Cox Engine of The Month
July-2019
Mike1484's

"Tee Dee .020 on a free-flight model"



PAST WINNERS
Speed Contest 2019
CEF Traveling Engine

Win This Engine!
The Traveling Prop
Gallery


Why the slanted glow plug on some Fox engines? Empty
World of Aviation

Why the slanted glow plug on some Fox engines?

Go down

Why the slanted glow plug on some Fox engines? Empty Why the slanted glow plug on some Fox engines?

Post  Kim on Fri Jan 13, 2017 4:34 pm

Spent some time this afternoon running a Fox .15 (got test-run fever here lately), and was wondering about the purpose of it's slanted glow plug.

Why the slanted glow plug on some Fox engines? 1_24

Why the slanted glow plug on some Fox engines? 2_26

Why the slanted glow plug on some Fox engines? 3_19











































Kim
Kim
Top Poster
Top Poster

I Support My Forum

Posts : 6625
Join date : 2011-09-06
Location : South East Missouri

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  NEW222 on Fri Jan 13, 2017 4:42 pm

Very good question I say. I have heard and seen these many times before online but never knew why either, but just never thought of asking. Glad you did!
NEW222
NEW222
Diamond Member
Diamond Member

Posts : 2189
Join date : 2011-08-13
Age : 40
Location : oakbank, mb

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  Mark Boesen on Fri Jan 13, 2017 10:39 pm

idk, several companies did the slant plug thing in the late 60's-early 70's (this was also a about the time a lot of larger R/C engines dabbled in dual plug head designed) i can only guess that there was some improvement in combustion with the element tilted into the direction of the intake?

This was also my first 'big bore' engine, went down to the new hobby shop that just opened in town, after school the last day of 6th grade. Bolted it onto a jr. Ringmaster, don't recall having any issues with it, it seemed to start decent enough and pulled the jr. ringmaster with good tension.

Why the slanted glow plug on some Fox engines? Scan0010
Why the slanted glow plug on some Fox engines? Scan0011
Mark Boesen
Mark Boesen
Top Poster
Top Poster

Posts : 3728
Join date : 2011-09-01
Age : 60
Location : Rockford, Il

View user profile http://groups.yahoo.com/group/049Collectors/

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  Oldenginerod on Fri Jan 13, 2017 11:16 pm

Kim wrote:.......wondering about the purpose of it's slanted glow plug.  

Why the slanted glow plug on some Fox engines? 3_19

Cross threaded??? lol!
Oldenginerod
Oldenginerod
Diamond Member
Diamond Member

Posts : 2563
Join date : 2012-06-15
Age : 56
Location : Victoria, Australia

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  Cribbs74 on Sat Jan 14, 2017 12:04 am

From what I have read it was designed to be a "swirl quench" chamber. Impoving combustion. I doubt it did a whole lot as it didn't last long. The 36X is the same.
Cribbs74
Cribbs74
Moderator

Trusted Seller
Posts : 10413
Join date : 2011-10-24
Age : 45
Location : Tuttle, OK

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  KariFS on Sat Jan 14, 2017 5:14 am

Do these have a flat top piston or is it somehow contoured to utilize the plug angle?

KariFS
KariFS
Diamond Member
Diamond Member

Posts : 1515
Join date : 2014-10-10
Age : 47
Location : Finland

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  OVERLORD on Sat Jan 14, 2017 6:05 am

The plug is positioned like that so the bottom of the plug is flush with the bottom of the cylinder head. The combustion chambre must be wedge shaped or maybe pent.
OVERLORD
OVERLORD
Diamond Member
Diamond Member

Posts : 1336
Join date : 2013-03-19
Age : 53
Location : Normandy, France

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  Kim on Sat Jan 14, 2017 7:41 am

Thanks guys.  

Yeah Ron, I've heard that term "swirl quench" before, maybe in an engine review by Peter Chinn. Can't remember any of the other details, so am searching through my stack of old magazines to see if I can find a review on this or a similar engine.
Kim
Kim
Top Poster
Top Poster

I Support My Forum

Posts : 6625
Join date : 2011-09-06
Location : South East Missouri

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  Kim on Sat Jan 14, 2017 7:44 am

KariFS wrote:Do these have a flat top piston or is it somehow contoured to utilize the plug angle?


Good question...gonna stick a flashlight in the exhaust port here in a bit to see if there's a web on the top of the piston.
Kim
Kim
Top Poster
Top Poster

I Support My Forum

Posts : 6625
Join date : 2011-09-06
Location : South East Missouri

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  GWILLIEFOX on Sat Jan 14, 2017 7:52 am

There is a baffle on top of the piston
GWILLIEFOX
GWILLIEFOX
Gold Member
Gold Member

Posts : 292
Join date : 2014-12-23
Location : Beaver Falls, PA

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  KariFS on Sat Jan 14, 2017 8:27 am

OVERLORD wrote:The plug is positioned like that so the bottom of the plug is flush with the bottom of the cylinder head. The combustion chambre must be wedge shaped or maybe pent.

Makes sense, although intuitively I would have made the combustion chamber angled the other way around Huh...
KariFS
KariFS
Diamond Member
Diamond Member

Posts : 1515
Join date : 2014-10-10
Age : 47
Location : Finland

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  pkrankow on Sat Jan 14, 2017 8:54 am

I am pretty sure those area all baffle piston engines. The angled plug suits the irregular shape of the baffled combustion chamber head better.

Phil
pkrankow
pkrankow
Diamond Member
Diamond Member

Posts : 2987
Join date : 2012-10-02
Location : Ohio

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  fredvon4 on Sat Jan 14, 2017 9:56 am

Ken Cook will know for sure.

I think I read somewhere that the slant plug had something to do with a side mounted engine close to the wing needing better access for start glow
fredvon4
fredvon4
Diamond Member
Diamond Member

Trusted Seller
Posts : 2775
Join date : 2011-08-26
Age : 63
Location : Lampasas Texas

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  GWILLIEFOX on Sun Jan 15, 2017 8:38 am

When Fox updated the 36X design he went to the slanted plug.  His ads said it was to allow easy, faster plug changes on combat models.  But it may also have had to do with performance.  Over the years engine manufacturers have moved the plug location all over the head.  McCoy really did a lot of this and so did Fox of course.  Fox's first ad for the new 36X in the Sept. 1964 MAN showed the tilted plug pointing the wrong way.  
Why the slanted glow plug on some Fox engines? 64090410
In the Nov. 1964 ad they got it right.
Why the slanted glow plug on some Fox engines? 64110410

varied plug locations:
1958 35RC Special
Why the slanted glow plug on some Fox engines? Fig_5_10
1958 Fox 15
Why the slanted glow plug on some Fox engines? 58-15-11
L&J modified Stunt 35s
Why the slanted glow plug on some Fox engines? Lj35_210
Why the slanted glow plug on some Fox engines? Lj_110
1972 fox Eagle 60
Why the slanted glow plug on some Fox engines? Evans110
1978 Fox Eagle 60 Export
Why the slanted glow plug on some Fox engines? 78-60_10
1980 Fox Eagle 60 USA
Why the slanted glow plug on some Fox engines? 80-60_10
Details of 1978 Export and 1980 Fox USA heads - both were designed for no or low nitro fuels
Why the slanted glow plug on some Fox engines? 80_exp11
Why the slanted glow plug on some Fox engines? 80_exp10
Fox 60 Stunt
Why the slanted glow plug on some Fox engines? Img_0110
GWILLIEFOX
GWILLIEFOX
Gold Member
Gold Member

Posts : 292
Join date : 2014-12-23
Location : Beaver Falls, PA

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  fredvon4 on Sun Jan 15, 2017 9:54 am

Ah Ha!...that is what I remember....not for easier glow clip, but much easier to replace with slanted plug where the head is in line and close to the LE making plug replacement difficult if dead center and tool to knuckle limited space....

I do not have any slant plug engines but can attest that a straight plug near the wing does NOT allow the use of a typical 4 way tool to replace the plug and then a screw driver tool is needed ----but still a pain to do (fast)
fredvon4
fredvon4
Diamond Member
Diamond Member

Trusted Seller
Posts : 2775
Join date : 2011-08-26
Age : 63
Location : Lampasas Texas

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  fredvon4 on Sun Jan 15, 2017 10:01 am

I ... on re-thinking of this... wonder how many reading appreciate that a LOT of COMBAT matches are won on the ground

Cuts, kill (in some rules), and airtime are part of the scoring

If a plane flames out from dead plug the pit crew needs a strategy, tooling, and access to new plug FAST!

Same with prop replacement

Although I have never flown it, but seems that CL racing or speed have similar NASCAR style pit crew drills and speed thinking
fredvon4
fredvon4
Diamond Member
Diamond Member

Trusted Seller
Posts : 2775
Join date : 2011-08-26
Age : 63
Location : Lampasas Texas

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  Ken Cook on Sun Jan 15, 2017 11:13 am

I always assumed it was due to the easier access to the plug. From my experience, no matter where the plug is located in the cylinder head it doesn't seem to make a hoot of difference. Mccoy did this all the time. While there's mention of the plug location making it easier to pit for the Combat X series, the later Mark series had straight plugs. I wish they didn't alter this as I had to modify my wrenches to gain access to the plugs. My engines are recessed back into the wing making a T-wrench or cross handle style obsolete. I think the question was a very good one because no matter who I've asked, I get the blank stare initially. Ken
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 3533
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  GWILLIEFOX on Sun Jan 15, 2017 1:32 pm

I think when the head button design became the performance standard most engines started using a central vertical plug.
GWILLIEFOX
GWILLIEFOX
Gold Member
Gold Member

Posts : 292
Join date : 2014-12-23
Location : Beaver Falls, PA

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  gcb on Mon Jan 16, 2017 8:12 am

From the top of my head:

In the fifties, when an engine was run hot (speed or racing) the hottest area in an engine was on center-top of the piston. It was known as hell's kitchen. Because of this heat, some engines failed at the top of the connecting rod or the wrist pin. Designs were tried that provided the best swirl of the incoming charge to cool off the top of the piston and a better burn of the fuel.

In 1960 Supertigre and K&B came out with a flat topped piston that used the intake porting to provide swirl. These were improved on with PDP (Perry Directional Porting) and eventually Schnuerle porting.

Another thing that came out during those times was the idle-bar glow plug. Be careful using them in old engines because some will allow the baffle to hit the idle bar...ungood!  

Besides, if the second generation Fox .15's didn't have the slant plug they may have been referred to as "drop-ins". Smile Smile

George
gcb
gcb
Platinum Member
Platinum Member

Posts : 908
Join date : 2011-08-11
Location : Port Ewen, NY

View user profile

Back to top Go down

Why the slanted glow plug on some Fox engines? Empty Re: Why the slanted glow plug on some Fox engines?

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum