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!


Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» GSCB meet this Sunday
by roddie Today at 3:48 pm

» Submarine ARA San Juan Lost in the sea ....
by Oldenginerod Today at 3:22 pm

» 1/2A Non-Contest Control Line Gathering
by xplaneguy Today at 3:14 pm

» Looking for a New In Box PT-19 from the 80s-90s
by kaylejwm Today at 2:04 pm

» Wen-Mac slotted glowhead
by roddie Today at 12:44 pm

» Recent engine acquisitions
by 1/2A Nut Today at 12:39 pm

» Happy Thanksgiving Friends
by Admin Today at 12:14 pm

» The Breezy Hill Flyers "Black Fly-Day" Event !!!
by fit90 Today at 8:53 am

» Drill Press Question
by getback Today at 8:10 am

» *** Double SIGH ***
by Kim Today at 5:15 am

Cox Engine of The Month
November-2017
MauricioB's

"Cox Tee Dee .010"



PAST WINNERS
Speed Contest 2018
CEF Traveling Engine

Gallery


Win This Engine!
The Traveling Prop
World of Aviation

Stepped Cylinders

View previous topic View next topic Go down

Stepped Cylinders

Post  WingingIt74 on Fri Jan 09, 2015 9:20 am

When where they produced? What bypass/boost configurations can you find on them?

_________________
-Travis

Winging It! with Travis & Jeremy
On FaceBook & YouTube
avatar
WingingIt74
Moderator

Trusted Seller
Posts : 3184
Join date : 2011-08-11
Age : 43
Location : Waterloo, IL

View user profile https://www.facebook.com/wingingit74/

Back to top Go down

Re: Stepped Cylinders

Post  balogh on Sun Jan 11, 2015 9:29 am

Refer to the middle of page 10 in the COX Model Engine Handbook. (I hope I am not infringing the copyright..)



Stepped or grooved cylinders were mainly in production till 1972 when a new honing machine was purchased by COX that did not require the groove...but the old honing machine was also used till 1976 so - as the book claims - grooved cylinders still were in sporadic production till 1976.
avatar
balogh
Diamond Member
Diamond Member

Posts : 1523
Join date : 2011-11-06
Age : 59
Location : Budapest, Hungary

View user profile

Back to top Go down

Re: Stepped Cylinders

Post  Motra on Sun Jan 11, 2015 10:11 am

I read somewhere that the reason for the thicker walled cylinders was for strength. If the cylinder was struck during a crash the weak area was where the exhaust ports were cut in - the cylinder would distort. They first added extra material around the exhaust area and left the bottom thin for weight savings, then later just made the whole lower section a uniform thickness. Is this entirely untrue?
avatar
Motra
Silver Member
Silver Member

Posts : 93
Join date : 2010-08-20
Location : SLC, UT

View user profile

Back to top Go down

Re: Stepped Cylinders

Post  balogh on Sun Jan 11, 2015 10:17 am

I guess the story about strengthening the cylinder by leaving it thick-walled is true, although I have never experienced any crack around the exhaust port area of thin walled cylinders. Some say it was occassionally inflicted even without a hard landing, if e.g. the engine was overheated (too high nitro %, poor cooling etc...)

The weight reduction with the groove may not have played an important role in the development of the design: just think about the latest cylinder shape which is thick-wall, and can be machined with fewer steps i.e. shorter production time and lower cost.. The groove was made there probably for the earlier honing machine, as long as it was in use.
avatar
balogh
Diamond Member
Diamond Member

Posts : 1523
Join date : 2011-11-06
Age : 59
Location : Budapest, Hungary

View user profile

Back to top Go down

Re: Stepped Cylinders

Post  WingingIt74 on Sun Jan 11, 2015 10:22 am


_________________
-Travis

Winging It! with Travis & Jeremy
On FaceBook & YouTube
avatar
WingingIt74
Moderator

Trusted Seller
Posts : 3184
Join date : 2011-08-11
Age : 43
Location : Waterloo, IL

View user profile https://www.facebook.com/wingingit74/

Back to top Go down

Re: Stepped Cylinders

Post  Motra on Sun Jan 11, 2015 10:25 am

WingingIt74 wrote:I really need to get one.....
http://www.modelenginecollecting.com/Cox%20Web%20Material/Cox-Book.html

Me too! I've wanted it for years but just never pulled the trigger.
avatar
Motra
Silver Member
Silver Member

Posts : 93
Join date : 2010-08-20
Location : SLC, UT

View user profile

Back to top Go down

Re: Stepped Cylinders

Post  balogh on Sun Jan 11, 2015 10:39 am

I have one and read it with mixed feelings.

At least the TD family - my favorite, and maybe the most famous COX engines - is discussed in less than 2 pages out of the 68. For me important information like production period of tapered wall design, various piston and rod designs etc. are still missing. It is certainly not to be blamed on the authors who looked into every tiny corner to collect the information still available, but in general the depth of information varies a lot accross the book.

Tons of pictures on engines with reference numbers to sub-versions, without explaining the technical difference between them.
But if you have the 35 bucks, you still may like it.
avatar
balogh
Diamond Member
Diamond Member

Posts : 1523
Join date : 2011-11-06
Age : 59
Location : Budapest, Hungary

View user profile

Back to top Go down

Re: Stepped Cylinders

Post  Mark Boesen on Sun Jan 11, 2015 10:47 am

If you re-read the article, it clearly explains why the thicker cylinders. it was never for strength or weight reduction.

The Cox book is missing a lot and is not 100% accurate, but it's the only show in town and well worth the money to a die hard collector or enthusiast.
avatar
Mark Boesen
Top Poster
Top Poster

Posts : 3359
Join date : 2011-09-01
Age : 59
Location : Rockford, Il

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

Back to top Go down

Re: Stepped Cylinders

Post  anm2 on Sun Jan 11, 2015 11:35 am

WingingIt74 wrote:When where they produced? What bypass/boost configurations can you find on them?

I have the handbook and I don't think it specifically mentions the different configurations, although if you go through the manual and check out all the different engine configurations you could figure it out. I am pretty sure they were made in almost every possible configuration. I have personally seen or held the following stepped cylinders: #1, #2, #3, #4, #6, #7. I don't recall seeing a #5 or a #8 but I am pretty sure they made them. In my opinion, the black widow with the stepped #1 is the most desirable of the BWs. Just my opinion. Andy

anm2
Gold Member
Gold Member

Posts : 285
Join date : 2013-03-30

View user profile

Back to top Go down

Re: Stepped Cylinders

Post  roddie on Sun Jan 11, 2015 12:20 pm

Hi Travis, This is one of three #1 cylinders that I have. I believe it originally came on a Golden Bee.

This engine arrangement is planned for my little "Phred's Phault" 1/2A Voodoo foamie.




Below is a photo of an obscure Cox .049 cylinder of which I have no idea of it's origin. It has no anodizing, no #.. and is single bypass ported. I have a 3-piece piston that I believe may have come with this cylinder.

Note the cylinder's minimum OD...



avatar
roddie
Top Poster
Top Poster

Posts : 5452
Join date : 2013-07-17
Age : 57
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: Stepped Cylinders

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

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