Sorry to flood the board with posts, but...

[batjac]

... questions just keep coming to me. I can't stop them, and the more I read on this site, the more questions that I have. I did a search, but couldn't find what specifically sets a Killer Bee backplate apart from the other backplates. How is it different from the others?

The Baffled Mark

[Admin]

The questions are alright, that's what the forum is for!


The Killer Bee backplate has a larger opened venturi intake and was sold without a screen. The Killer Bee .049 was sold with a black backplate and the .051 was sold with a red backplate. The only difference between the red Killer Bee backplate and the black killer bee backplate is the color. "Real" pre-Estes Killer Bees used a yellow strawed needle valve while the later Estes Killer Bees used a regular short black capped needle valve.

Here are some picture I just took of several different backplates and a Killer Bee .049 backplate.


These are two product engine backplates. The gray backplate is better known as a SureStart backplate.


White car engine backplate. No screen with open intake.


This is a SureStart backplate with the screen and spray bar removed.


This is a Killer Bee .049 backplate. Notice how there is no screen and the intake is less restricted. The black backplate in the first picture has a open intake like the Killer Bee but has a screen.


SureStart backplate


Product engine backplate (black with screen)


Killer Bee backplate

I don't yet have every backplate style so I can't take pictures of them all, there are a few others on engine I have put away. I should have some technical info about all this somewhere around here. I'll try to dig it up. Maybe Mark or Mud will chime in with some more info.

[Kim]

Actually, it'd be great for some more guys to check in with more info on just what constitutes a "Killer Bee".  My flying bud Patrick has bugged me with his homemade version for a long time.  The thing has never run well enough to suit him, and he keeps coming up with all kinds of weird reasons for it's problems.

I've never dealt with Killer Bees other than with the Tach Race, and would like a bit more info, if possible, on the make-up of both the real KB's and the Estes' versions.


Thanks !

[crankbndr]

I'll take a stab at it, but there could be errors.

                                               Killer Bee                                                             Estes
crankcase                        gold anodized                                                          plain aluminum color           both have KB prop drive plate and  washer
crankshaft                       balanced KB crank                                                    standard crank
cylinder                          tapered bore, slotted exhaust, bottom slot larger           no tapered bore, same exhaust slots
                                    than top
piston                             tapered piston,  2.75 grams weight                             standard piston  3.15 grams
back plate                       KB back plate, no screen                                           same
needle valve                    yellow plastic extension                                             black cap on NV
head                               high comp. head                                                      same

If NIB look for 1996 stamped in the cardboard sleeve, it should be there. I have never held a real KB that did not have the yellow NV extension but I think some have black capped needle.

[andrew]

I would like to know what preferences you folks have concerning hole placement in the spraybar. Directly downstream, 15 degrees off, etc. I can see arguments for different positions, but the proof is in the pudding (or performance).

[crankbndr]

This KB now on eBay has some abnormalities, red backplate is for .051 and the needle valve. I would need to see the date stamp and crank before raising the bid.

http://www.ebay.com/itm/Rare-Cox-Killer-Bee-049-cu-in-Model-Engine-NIB-/390613859757?pt=US_Radio_Control_Control_Line&hash=item5af2667dad

This one is all wrong and I doubt its from 1996.

http://www.ebay.com/itm/VINTAGE-1996-COX-049-KILLER-BEE-/271224257659?pt=US_Radio_Control_Control_Line&hash=item3f2639bc7b

[Admin]

Yeah, it should be said that I wouldn't go by the backpate color anymore when determining a Killer Bee as a .049 or .051. With Matt and Bernie selling the red backplate assemblies, people could just easily swap the backplates. Same goes for the yellow strawed needle. If you are looking for a "real" Killer Bee, be sure there is a date in the box, and it has an original lightened crankshaft. For a .051, be sure there is a groove on the skirt of the piston.

[stevej]

.051 Killer Bees have two grooves in the piston skirt.

[Kim]

How about the needle valve / spray bar assembly? I thought the threads were the finer version, but any interior differences in the spray bar bore it's self?

[RknRusty]

How about the needle valve / spray bar assembly?  I thought the threads were the finer version, but any interior differences in the spray bar bore it's self?

Standard spray bar. Too bad it's not a fine thread.

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