Are the Leisure Dynamics Black Widows supposed to have slotted exhaust?

I do know some of the late 1970s early 80s Black Widows did come with the slotted cylinder. The cylinder was a 2 bypass, 1 boost port on each bypass, top fin milled with no SPI.


EDIT:
In fact, take a close look at the engine on the manual in this auction. http://www.ebay.com/itm/Cox-049-Black-Widow-/160904245801?pt=US_Character_Radio_Control_Toys&hash=item2576a3f229&nma=true&si=iAxSFYBXGfmlHdvRB8gPoHtw%2FSQ%3D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

If anyone has that manual, I would like a scan of it for the library.

Admin wrote:I do know some of the late 1970s early 80s Black Widows did come with the slotted cylinder. The cylinder was a 2 bypass, 1 boost port on each bypass, top fin milled with no SPI.

It's the "no SPI" part that I didn't like about those. I always wondered why they crippled the good old BW like that. But I believe the thinking was the fluted(boost) ports in the new cylinders put the power back that removing SPI robbed.

Maybe someone has done a torque/HP comparison between a #1 P/C and a newfangled fluted non-SPI P/C on the same engine.

Jason_WI wrote:Leisure Dynamics owned Cox from 1969 to 1983 when Bill Selzer purchased Cox out of bankruptcy.

According to the Cox engine handbook the BW never shipped with the twin slit exhaust. Also states production discontinued in 1996 but we know that Estes shipped their version of the BW until 2005.

But that doesn't mean Leisure didn't ship it with one when parts were short and times were tough in the late 70's.

Does this cylinder have SPI?

Hi thanks for the reply. And it does not have SPI

Admin wrote:I do know some of the late 1970s early 80s Black Widows did come with the slotted cylinder. The cylinder was a 2 bypass, 1 boost port on each bypass, top fin milled with no SPI.


EDIT:
In fact, take a close look at the engine on the manual in this auction. http://www.ebay.com/itm/Cox-049-Black-Widow-/160904245801?pt=US_Character_Radio_Control_Toys&hash=item2576a3f229&nma=true&si=iAxSFYBXGfmlHdvRB8gPoHtw%2FSQ%3D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

If anyone has that manual, I would like a scan of it for the library.

Not sure if this helps, but I just looked on the back of the instructions and it has a date of 1980 and the cylinder is not numbered at least not that I could see, has 2 bypass ports, no boost ports and no SPI. Maybe someone switched out the piston and cylinder.
However, my other B.W. w/ plastic back plate and hex drive plate (Estes Version?) has a non-slotted exhaust, 2 bypass , no boost ports but has SPI.
And I will try and scan the instructions for you.

If I understand correctly, the instructions show an open exhaust but your engine has slit exhaust. Cox did make the hex drive plates before the slotted exhaust with boost flutes came along. All BWs before 1996 had the #1 cylinder you describe(some were not numbered), with open exhaust ports, dual bypass, no boost flutes and SPI, and latest of those had hex drive plates and plastic backplates. I have a BW that I bought in '93 that had no number stamp, but everything matched the ones with the #1 stamp on the corner face of one of the exhaust ports, and it had a plastic backplate.

If you have a metal backplate,yours is probably an older one, pre-'96, but someone installed a new type cylinder. It should perform fine. I think the Boost port design with no SPI probably had comparable performance as the older #1 SPI P/C. To get SPI with the new type cylinders they use a short skirted piston. That will turn higher RPMs but since the piston is lighter, possibly less torque. That torque assumption is just my personal non-proven theory.

sdjjadk wrote:
Not sure if this helps, but I just looked on the back of the instructions and it has a date of 1980 and the cylinder is not numbered at least not that I could see, has 2 bypass ports, no boost ports and no SPI. Maybe someone switched out the piston and cylinder.
However, my other B.W. w/ plastic back plate and hex drive plate (Estes Version?) has a non-slotted exhaust, 2 bypass , no boost ports but has SPI.
And I will try and scan the instructions for you.

There is a chance my cylinder info is incorrect, I obtain info about engine that I don't have from other people. Plus data gets shifted all the time when things are added to the list, its not uncommon for me to find an error every so often.

Do you have a picture of your engine?

From what it sounds, I would say your engine is original. There are just too many used and NIB black widows out there with slit cylinders, plus some of the manuals feature a slit cylinder Black Widow.



This is the manual I am looking for, I already have the usual #1 open exhaust Black Widow manual. I would assume the manual featuring the slit cylinder black widow would also feature an engine diagram with the slit cylinder and corresponding part number.

Hi Shawn,
This subject (and lots similar besides) have been done
To death on here with the usual conclusion
Being that sometimes Cox used whatever was
Laying around at 'boxing up' time. Allied to this
Perhaps some staff may even have created their own
'specials'.
Possibly a modern day version of a future debate
Will be how many Cox Blue Bullets were made in
About 2012? We all know it's a Hundred right?
Well, take a look at my Avatar and you'll get
The picture.

here is more info for the slotted port of a BW.

https://www.coxengineforum.com/t18-estes-black-widow

I got three slotted BW. one is from the leisure dynamics era.

Admin wrote:

There is a chance my cylinder info is incorrect, I obtain info about engine that I don't have from other people. Plus data gets shifted all the time when things are added to the list, its not uncommon for me to find an error every so often.

Do you have a picture of your engine?

From what it sounds, I would say your engine is original. There are just too many used and NIB black widows out there with slit cylinders, plus some of the manuals feature a slit cylinder Black Widow.



This is the manual I am looking for, I already have the usual #1 open exhaust Black Widow manual. I would assume the manual featuring the slit cylinder black widow would also feature an engine diagram with the slit cylinder and corresponding part number.

I'll try and post pics tonight.

Shawn

Sorry I haven't been able to post pics yet. I just got over being under the weather.

Shawn

Sorry John put it off long enough...I have search here and got to ask

How did you get the other crank case in your avitar? is My #55 blue Bullet one of 100 or one of 101?

101 Fred but shhhh don't tell anyone.

This could be our great grand kids 'black space bug'
Debate in 2050....




Seriously though my Extreme was 007 when Bernie asked if
The previous purchasers were interested in the same No BB
I confirmed 007 when it arrived it was 7.
Bernie being the Gentleman he is, employs staff who are just
As customer focused and Theresa had 007 made and in the post
Before I could even say "I'll return 7".....

Sorry for the brief hijack to the OP...

Yes I find Bernie and crew are very good at taking care of us. Great selection, fair prices and shipping, fast processing, and AAA+ customer service and communication.

Thanks for clearing up my curiosity. Around 2050 the unique #7 will bring 300% of $89.99 in inflation adjusted and collector bidding dollars....grin

I'm just gonna have to stick around I guess

Here is a pic of my B.W.


I'll post pics of the manual when I get a chance.

Shawn

I have the identical engine that Shawn has pictured. I don't have the box as I bought it used some years ago. It's the only slotted cylinder Black Widow I own. I always thought that the engine I own wasn't in stock form. Does anyone recall the manufacturing date of these engines? I'm just stumped as I don't recall seeing slit cylinders until the mid 80's. . I have some dual ported Babe Bees from 1984 that appearance wise look like a Sure Start cylinder. Even though they have the dual ports, they don't have the small transfer channels alongside of the ports. They run surprisingly strong and I recall their performance certainly not Black Widow but very close. Ken

I have always believed these Black Widows, as well as the permanent move to slit cylinders on the Babe Bee was done sometime between 1978-1982. I'm not 100% sure as I came up with these numbers after putting together all the details some such as round brass driveplates, the years Leisure Dynamics ran Cox (and the fact I mostly noticed that the packaging that featured these engines had Leisure Dynamics on it), metal backplates, the Snap Starter and starter cam.

We know that Leisure made changes in their late stages...  

The original in 1974 had open exhaust ports but the 1979 to 1984 Catalogs shows a Black Widow with a Slit Exhaust.

After that it went back to being open, until 1997 when who knows what happened with Estes.

Cheers

 this is mine and the box is in rough shape no date stamp ..but has perforated machine made markings of EFG inside the cardboard backing ? what does that mean ? I got it so long I could nt find the post of the year he thought it was....Eric

I remember Larry Renger telling me that those dual bypass with one boost port non SPI cylinders were quite good, in fact better than the standard twin bypass with SPI cylinders. Even the late model Tee Dees used that setup and the venom but they had SPI and open exhaust which made them even better.

We had one of those dual slit exhaust Black Widows on a Baby Clown that went really well with a 3 blade 5x3 tornado prop.

There sure were a lot of confusing changes and variants to each engine over the years.

Cheers

There are some that contend that the open exhaust ports were so oversized that the slits did not affect the power at all. I have also heard what Warren said, that the single boost port worked better. If that's the case, Bernie's modified Surestart-to-Tee Dee P/C replacements may run better than the old #4, except for the lack of a tapered fit.
Rusty

Edit : deleted and post in https://www.coxengineforum.com/t6575-2-slit-exhaust-on-a-black-widow