shoestring untied

Hey there.. How about a Cox Tee Dee .09?

Hello, my best guess would be late 50's early 60's Thanks Mark

roddie wrote:Hey there.. How about a Cox Tee Dee .09?

Would that engine have been around in the late 50s.
Thanks Mark

Mark Diedrichs wrote:

roddie wrote:Hey there.. How about a Cox Tee Dee .09?

Would that engine have been around in the late 50s.
Thanks Mark

No, early 60's was when the TD line was introduced.

OS PET .099 with 2 head screws was from later 50's

https://www.osengines.com/history/osm640/osm-1957-pet-09.jpg

This would be pretty close to the time frame.

https://www.ebay.com/itm/Pet-OS-099-Model-Airplane-Engine-With-Finless-Head-And-Propeller/162835507333?hash=item25e9c0a885:g:mVQAAOSwyXNaTkLY

Add a 701 muffler for quiet operation.

Mark, the Sig Shoestring was designed for .15 size engines. The box just claims that it makes an ideal trainer using a .10. If I was going to look for a .10 it would be the OS MAX-S .10. .10 size engines were just not as common they generally cost the same as .15's and their displacement made it slightly difficult because they were caught in between prop sizes. Some of the other suggestions would work fine. If a kit offers engine sizes from smallest to largest, it's a good practice to go with the larger. Ken

Thanks for the info, now I know what to look for. Mark

Well, according to this website compiled by a die-hard SIG fan showing an almost comprehensive list of SIG planes, the year next to the CL-13 Shoestring is 1975.

The website is HERE.  The kit is shown half way down the page.

I am not sure if he means it was first produced in 1975, or the kit shown is from 1975, but the other planes listed in order seem to be the right time period from what I’ve seen in the past.  On the old build sheets, SIG used to have a year on them, so if you can look at all your paperwork it might give you a year your kit was designed.  If it was 1975, then a Medallion .15 or TD .15  would be an excellent engine for the plane. I have emailed the website owner to confirm that the kit was released in 1975, and I will update when I get a response.

The Kit Raider Mark

Mark Diedrichs wrote:Hey everybody, I'm looking for a period correct engine .10 for my next build, the shoestring. Thanks Mark

OK Cub .149 if you like it loud.     Certainly period correct.

i was gonna suggest the Cub, but why not the most common .15 ever made...the Fox .15?

cheep and plentiful, this is probably at the top of price:

https://www.ebay.com/itm/Vintage-FOX-15-X-C-L-ENGINE/273003779788?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D44039%26meid%3D7aa2875521fa42e3808d26dbaa16a27a%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D202165981652&_trksid=p2047675.c100005.m1851


or this, it should sell for more but with eBay you never know and you'll know it's a great engine:

https://www.ebay.com/itm/NICE-OLDER-OS-MAX-15-SHINY-CASE-CONTROL-LINE-NITRO-MODEL-AIRPLANE-ENGINE-wBOX/202174403707?hash=item2f1288947b:g:FacAAOSwZvRaTvIq

Mark Diedrichs wrote:

roddie wrote:Hey there.. How about a Cox Tee Dee .09?

Would that engine have been around in the late 50s.
Thanks Mark

You could go for a Cox Sportsman .15 (1958) or Olympic .15 (1959). You would have to accommodate the rear carb. The Tee Dee's appeared in 1961.

Mark Boesen wrote:i was gonna suggest the Cub, but why not the most common .15 ever made...the Fox .15?

cheep and plentiful, this is probably at the top of price:

https://www.ebay.com/itm/Vintage-FOX-15-X-C-L-ENGINE/273003779788?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D44039%26meid%3D7aa2875521fa42e3808d26dbaa16a27a%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D202165981652&_trksid=p2047675.c100005.m1851


or this, it should sell for more but with eBay you never know and you'll know it's a great engine:

https://www.ebay.com/itm/NICE-OLDER-OS-MAX-15-SHINY-CASE-CONTROL-LINE-NITRO-MODEL-AIRPLANE-ENGINE-wBOX/202174403707?hash=item2f1288947b:g:FacAAOSwZvRaTvIq

If it truly is a 1975 kit then a Fox .15X would have most likely resided on the nose as Mark suggested.

i know that from experience gatafish stuff on the bay has been true to his word https://www.ebay.com/itm/NICE-OLDER-OS-MAX-15-SHINY-CASE-CONTROL-LINE-NITRO-MODEL-AIRPLANE-ENGINE-wBOX/202174403707?hash=item2f1288947b:g:FacAAOSwZvRaTvIq is what i would do if you want a Fox

Stop The Presses!!!

I forgot about this the first time I posted here, but I remembered a few minutes ago.  If you look at the pics of the SIG Buster on the page I posted, there are two pictures of the Buster kit box.  The first picture has the same yellow starred border around a teal background.  The wording on the label is identical except that it says "Buster" instead of "Shoestring" as Mark's box does.  This would show that they are of the same vintage.  They were both produced at the same time for club racing, and designed by the same designer, Mike Stott.  The Buster is kit CL-12 and the Shoestring is CL-13




The cover picture on the Buster kit box clearly shows the model with a Cox .15 engine on it.  Mystery solved.  Mark's Shoestring needs a Cox .15 on it!

The Detective Mark

The plans usually show a recommended engine that the kit was designed around.

I certainly won't dispute the box art. I just wouldn't assume the box art is the engine of choice. Even today, I know some who build for the designer and rarely fly the models themselves. The Sig kits were  event designed  kits around .15's like the Fox and Super Tigers. The Sig kits were designed  for the slant plug .15's. Goodyear events from coast to coast evolved into what the guys located in certain areas desired. There were generally 2 classes of .15 Goodyear A&B class or 1&2 which one of them being high performance and the other low performance entry level events.  I don't know if the builder just desires certain nostalgia. I have been involved with .15 sized racing events since the mid eighties and I never witnessed one of these planes with a Cox Medallion or TD .15 on the nose. Not saying it's not a formidable choice or couldn't be used.  Of the Cox engines  used, it was the Conquest in glow or converted to diesel.  Seeing the planes design was simple and the easy availability of the Fox, it made it a hands down choice for entry level racers wanting to try their hands at racing. For the most part, it was a smaller version of Foxberg racing with a slightly different set of rules.

I got a reply from the owner of the SIG history site.  He agrees that it was flown with a Fox.  Ah, well.  I tried for a Cox engine...


Hi Mark!  I'm glad you like the website - it's been a lot of fun putting it together over the years.  1975 was the year that the CL-13 Shoestring was introduced by SIG.  It's widely believed that the prototype flew with a Fox .15 and 6X4 prop.  My own flies with a un-muffled Fox .15 and 6X6 prop (yeah, I'm lucky in that I fly on a field that's far away enough from people).

Just a note here - the Cox Conquest .15 (being that you're in the Cox Engine forum) would definitely be of the right time period also but IMHO it might overpower the Shoestring.  Would be fun watching/hearing one in the air though.

Dave Wittich
AMA #94881, VR/CS #208
Yahoo - dwwsmw52

The Go-Between Mark

Thanks for all the info I'm going with cox conquest. There is one on ebay for too much money. Anyway I'll keep lookin. The shoestring deserves it. Thank You, Thank You!!! Love this site & the people, you folks know what your talking about. Mark

If you search for conquest .15 you will also get the K&B versions and RJL versions.

This guy is smoking good stuff:

https://www.ebay.com/itm/NEW-Rare-and-Beautiful-Cox-Conquest-15-RC-with-mufffler/263418430855?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20131017132637%26meid%3D1b186cd5e1a04c8091e91b1d5ce899ce%26pid%3D100033%26rk%3D2%26rkt%3D8%26sd%3D263418430855&_trksid=p2045573.c100033.m2042

If you are looking for the CL version:

https://www.ebay.com/itm/Vintage-K-B-Cox-Conquest-15-Control-Line-Glow-Engine-for-Model-Airplanes-CL-FF/263426408622?hash=item3d557000ae:g:cSUAAOSw~3paU9Xv

Remember you can always convert a R/C version over to control line with parts from MECOA. The timing and porting is the same.

https://www.mecoa.biz/shopdisplayproducts.asp?id=105

Jason