rainedave

My Feedback: (1)

In comparing various Cox reed backplates I've noticed that the venturi opening on my black plastic Texaco backplate is noticably larger than those on the older metal backplates in my collection (some are gold anodized others are bare metal). They all still have the screens in place so I doubt any of them were ever modified.

Logic wants to make me think that a smaller venturi is better suited to Texaco style running: less air, less fuel, longer run time. Since you usaully need a pump or pressure bladder with larger venturis I've always assumed they draw more fuel as well as more air. So why is its venturi the largest in my collection?

Thanks,
David

ptulmer

My Feedback: (5)

Because the black backplates are from Killer Bees? Never seen a product engine with a black backplate and the KB's venturi is huge in comparison.

Tim Wiltse-RCU

David,

The Cox Texaco was a tank mounted engine with the 8cc red anodized tank attached to it. Is this what you have or so you have something that has a product engine/Sure Start type backplate? If it's the real Texaco with the tank then the tanks backplate should be drilled out to something like .060" or around there. A Black Widow is around .082". The Babe Bee would fall in between. If you have a Texaco with a large hole then it could either be a replaced part if the engine was used or a mistake at the factory(good figure). I have a couple real real look Babe Bee/Golden Bee metal backplates that have little tiny holes in them and no crimp for a intake screen.

Patrick,

Most "product engines" backplate were black.

Later,
Tim

rainedave

My Feedback: (1)

Yes, it is a stock Texaco purchased around 1992 or so. It has the large Red anodized tank. From what you say, it sounds like a factory worker put a Black Widow backplate on a Texaco tank/engine.

I will take some measurements and post some photos after I finish my bacon and Cap'n Crunch.

Thanks.

KidEpoxy

Bacon & Capn Crunch?
Are you related to Uncle Dave with his Hotdogs & Kraft Dinner?

ahhh... sometimes I really miss Living La Vida Bachelor.

rainedave

My Feedback: (1)

At the last second I did a complete 180 and went with Frosted Mini Wheats instead. Years of living on the edge like this is why my hair is gray.

ptulmer

My Feedback: (5)

Sorry 'bout that rainedav. I should have had my morning kibble before posting.

Tim, you pulling my leg? I've seen white, red and grey. Never seen a black product engine!

gcb

I do not have a KB but my Texaco has a gray backplate. The BW's, when they went to plastic backplate and vented tank, won't work on a Texaco because the Texaco has a fill tube and vent hole on the backplate, and the BW does not. The screen holes in the back appear to be the same size.

Later runs of the BW used a non-vented plastic tank and a vented backplate like the Texaco. These are now sold as Babe Bees (with apparently a Sure Start front end). The Cox site has neither the BW nor the Texaco listed.

George

rainedave

My Feedback: (1)

Ok, here's a pic. The inside diameter of the hole in the plastic - the area that the screen covers - is just over 3/16" in diameter, or about .19" or so.

You can clearly see the fill tube on the backplate. Not visible in the photo is a small pin hole vent next to the fill tube.

Tim Wiltse-RCU

patrick,

no really most of my product engine backplates I have is my crap parts box are black..really.

Later,
Tim

burtcs

rainedav:

The backplate on a reed valve engine does very little except hold the needle valve; it admits air -
that's all. The venturee is where the work gets done. The venturee is located in the tank, in the case of the "product" engine it's the intake port.

Sure Starts are one form of the product engine. They flew kind of the junky plastic stff that Cox made for years. They came in different colors as noted, black, red or white (ivory). No difference that I can dectect. Some were little square units that clipped in, some were bigger and had four mounting holes.

The Texaco tanks have a very small venturee, next come the Baby Bee type engines and finally the Black Widow. What
they (Cox) are doing now I don't know. If I had my druthers I'd use the product backplate with an external tank. The Sure Starts I've examined still have the large intake port and they rock; Moreso than Black Widows.

I think Cox assembled engines using buckets of parts, sometimes they were the right ones and sometimes they weren't. The engines ran anyway. They were filling a quota and meeting a deadline.

Drill out the backplate all you want; it won't help much either way and you won't find any
power there

HTH - Steve B.

ptulmer

My Feedback: (5)

Burtcs, the parts come from oil filled fifty gallon drums! (man, what would I do with a couple fifty gallon drums full of Cox engines!) That's what I understand, anyway. They have more drums, but no plans on what to do with them. Heck, I'd be happy if they kept providing Surestarts for a few more years.

rainedave

My Feedback: (1)

Doh! Man, am I spacing out. What bothers me is that I've actually drilled these things out before, years ago for FF models. So at some point in my life I must have known what I was doing. Not any more, I guess! I think they call it "Sleep Intertia" when it takes you three hours to wake up in the morning. Maybe I should have gone with the Cap'n Crunch.

Tim Wiltse-RCU

When I talk about drilling a backplate on a tank mounted engine I include the tank too. I have found that if you open up the backplate and not the tank tube also it will have fuel draw problems.

Later,
Tim

small_rcer

Many years ago I ordered from Cox 6-10 backplates and needle valve assemblies for product engines. With the parts list I had, the product backs were black. We were taking the tanks off QRC, and Black Widows and making them into external tank designs. They worked fine. I wrote a list of suggestions and some questions to Cox, and got a letter back and some sample props from Mr Selzer ( spelling? ) One of the suggestions was they make an engine that used a product back and the twin ported Cylinder from a TD. I had been using the Black Widows without the slits for exhaust and they were our favourite engine. Now we find the Sure Starts are the simplest most reliable way to have fun and very affordable.

So product backs were available in Black and I still have 2 or 3 new ones. Well not "new" but still unused ;-)