Several Questions

Thanks for quick reply Bernie. I am actually using a Diesel head I got from you.

Godsey3.0 wrote:

Sixth: How do I use this tool? I need it to measure some drill bits (about 100) I recieved to find one that is .081"

I thought about writing up some basic instructions, but then, why re-invent the wheel? Here is a link with pictures added:

http://www.tresnainstrument.com/how_to_use_a_dial_caliper.html

andrew

Sweet. Thanks. Theirs was in CM and mine is in inches but I still got it. I found a bit that is .081". Will this still help performance? Or is the bit I need in Centimeters?




Edit: Just checked it in my Black Widow backplate. It fits in with a little snagging. It does not fit into my Babe Bee backplate.

If you had not already caught on I am trying to make a higher end diesel engine. It was a Babe Bee that I put a Killer Bee crank in and later gave it a #2 (Hope that is the right number. Same as Black Widow) Pylinder assembly. I also put on a Kavan Tank extender on it. Ran it as glow and got 3 minutes and 10 seconds with a 5.5x4 Cox propellor.

The Black Widow style backplate and tank were 0.082" stock.

I'd use a #45 drill (0.082") or a #46 drill (0.086") if you are drilling through a Babe Bee backplate/tank assembly or an older Golden Bee one. If you have the Black Widow one, it should already be 0.082" so I suppose you could open it up to 0.086".

Matt

How much will this help with performance? Gotta see if I have a .086" bit.

Rolla

Cox International wrote:Backplate only.

They are prone to leakage.

Should be OK for diesel as they are made of Nylon.

If you enlarge the venturi on an un-modified Babe Bee, you have to open up the backplate air inlet and the venturi tube. I have a small standard set of bits. I finger twist a 5/64 bit, the closest I can come, and the hole is .0078". I finger-spin it enough to make it a loose fit. It is indistinguishable, performance wise and probably about .082 anyway. Don't use a power drill, it goes through almost as soon as you give it the slightest twist with your fingers. Keep in mind, a Babe tank has a smaller venturi outlet behind the reed than the screamer Bees. Like Bernie said, a Black Widow tank and backplate (and probably all 8cc stunt tanks) is bored to the larger specs.

Godsey3.0 wrote:How much will this help with performance? Gotta see if I have a .086" bit.

Rolla

It'll help if you have a cylinder that can handle the extra charge. If not, you'll get an engine that doesn't want to start easily or needle steadily, and not much, if any more power. You can get a basic SPI set, a Black Widow II set or a Tee Dee set. Ramp it up as much as you want, those are the basic choices for how to turn that extra fuel/air volume into usable power.

Don't sweat a few 1000s, what Kim has on Lucky 13 is all you need. That Bee spins up well.

I already have an SPI set on it. Same as a black widow.

Ok. So here is what I have to do. Just to clearify.

1. Drill out venturi in backplate. Just gonna use .081". Is all I have right now. Can enlarge it rest of way later.
2. Remove reed for step 3.
3. Drill (By Hand) venturi in tank since it is a Babe Bee.
4. Make sure no shavings are left in tank.
5. Assemble and run.

Is this all that needs to be done?

Edit: Just checked Kavan venturi tube. It is also small. Even on the Black Widow extender. Needs to be enlarged.

Godsey3.0 wrote:Ok. So here is what I have to do. Just to clearify.

1. Drill out venturi in backplate. Just gonna use .081". Is all I have right now. Can enlarge it rest of way later.
2. Remove reed for step 3.
3. Drill (By Hand) venturi in tank since it is a Babe Bee.
4. Make sure no shavings are left in tank.
5. Assemble and run.

Is this all that needs to be done?

Edit: Just checked Kavan venturi tube. It is also small. Even on the Black Widow extender. Needs to be enlarged.

I'd strongly suggest putting the backplate, tank, and extender tube together, then drilling it as one in the diameter of your choice. This will ensure uniformity of all pieces.

Matt

I am definitley doing this with a drill press. It will do it straight and make it nice and smooth.

BRB: Gonna bore it out...

Start smaller --- you can always make it larger. Here's an excerpt from Paul Gibeault's Mouse Race Guide:

With the tank and tank back together, check that the venturi size is .082" I.D. If not, drill out
the tank and tank back inlet venturi to .082”, (this is what the record holding engine used).
Drilling out the venturi larger than .082” sometimes produces an rpm gain, but often your
engine won't run as steady and your range will be less. To me, it's just not worth it.

Godsey3.0 wrote:I am definitley doing this with a drill press. It will do it straight and make it nice and smooth.

BRB: Gonna bore it out...

No. Bad idea. It doesn't matter if it's straight, it's hollow and way wider than the bit inside the tube already. It's in before you realize you've done it. Just pick up a drill bit and do it.

Well that was fairly easy. I ended having to do the pieces separate. It did not want to stay together very well when I was getting ready to drill it. Now to clean it up and test it.

Rusty: I went VERY slow with the drill press. I wanted to make sure I did not mess up. I am used to drilling through solid metal. Always take it slow with that. So I just did the same.

If you want to extend run time do this: https://i.imgur.com/Kixi7.jpg
I also get an extremely even needle setting. I think it might have to do with the fuel not getting super heated in the tank.

I did that to a Pee Wee. Works nice. If I am going to use a separate tank ,though, I am just gonna use a product backplate. This was done for use on a Control Line plane.

Rolla

Godsey3.0 wrote:Rolla

As meticulous as you are, I'm sure it will run like a peach. A fast peach... You are as bad as I am at over-thinking whatever I'm engineering. (Just ask Andrew)

Now the pressing question: What does "Rolla" mean? It that your name? Is it a contemporary acronym that only smart phone and Facebook users know? I have an inquiring mind.

RknRusty wrote:

Godsey3.0 wrote:Rolla

As meticulous as you are, I'm sure it will run like a peach. A fast peach... You are as bad as I am at over-thinking whatever I'm engineering. (Just ask Andrew)

Now the pressing question: What does "Rolla" mean? It that your name? Is it a contemporary acronym that only smart phone and Facebook users know? I have an inquiring mind.

It's his middle name - too many Jacobs.

JPvelo wrote:If you want to extend run time do this: https://i.imgur.com/Kixi7.jpg
I also get an extremely even needle setting. I think it might have to do with the fuel not getting super heated in the tank.

Yes, that works well, next best thing to a tankless backplate. And it keeps the nose balanced if it's a retro-fit.

microflitedude wrote:

RknRusty wrote:

Godsey3.0 wrote:Rolla

As meticulous as you are, I'm sure it will run like a peach. A fast peach... You are as bad as I am at over-thinking whatever I'm engineering. (Just ask Andrew)

Now the pressing question: What does "Rolla" mean? It that your name? Is it a contemporary acronym that only smart phone and Facebook users know? I have an inquiring mind.

It's his middle name - too many Jacobs.

Ah, and now we know... the rest of the story.

Rolla is my middle name. It was my Step Grandfathers first name. I have only ever heard one person pronounce it correctly upon just seeing the spelling. Not sure why. Most people just do it wrong. Some do it wrong even after I tell them how to.

Ran the engine. Had to change the reed. Gotta get a different spring on the Needle Valve so I can really dial it in. It ran pretty nice. Too much any direction though and it would fluctuate quite a bit. Definitely ran faster. Need to time it. Gonna open it up for the last time (hopefully) and clean it up. Make sure it is all good inside it. No burs destroying the crank and such.

Rolla