gkamysz

My Feedback: (19)

Interesting idea. Did anyone actually understand what Peter is saying though? It's one thing to do an open source engine project but something completely different to actually produce something. The things that need to be researched are how to make an ABC, AAC, or whatever liner, sourcing the proper material to make pistons. I'm sure some of you have GZ, VA, Shuriken, Cyclon, and other engines to steal running fits and design ideas from. Also is there a plan for parts support?

Anyone know what a Picco P-Zero (the .8cc car engine) is capable of? I have one and it's beautifully made, but I haven't run it or even seen HP specs on it.

Toad

It really isnt that hard to learn what materials you want to use, what machines needed, and where to buy raw stock.
The problem is in financing a production effort in hopes of at least getting your investment back. How to make it is easy, finding skilled help will be hard, So learning the skills needed would be fun. Now a feller could just have the asian mfgs do it, but that takes away the fun!
I really think you all will have much more fun just making a few for your group here. Realize too that if succesfull, you can bet your bottom dollar that it will be copied and mass produced. (CS is famous for that and I know they monitor this forum, at least Zou does, the american connection for them)
IF I were to make this thing, it would be AAC, and use the Nelson Plug, a second version would use a carb, and lower timming for that application. The nelson plug is so much easier to get. Time to get after making that first case Tim!

Andrew

A question for those who know (I don't).

Is there a friction penalty incurred when running a rear rotor engine, and if so, is it compensated by better breathing?

build light

Quote by Andrew:
"Is there a friction penalty incurred when running a rear rotor engine, and if so, is it compensated by better breathing?"

Wow! What a great question. I would never have thought of that myself. I can hardly wait to find out the answer.

I have a good question myself. How about a plastic crankcase? To me, one of the biggest downfalls to the problem of engines in general is the weight of the block or crankcase. I have read about Chevrolet and others having experimenting with such things.
Cox probably had the best possible metal crankcase with the extruded aluminum they used. They even used plastic as part of the Medallions and Tee Dees.
As for the cast engines such as the Cubs, Enya, K+B, O.S. and the like those things are horrendously bulky and heavy.
Of course, the plastic could be injection molded or rather at first simply machined from plastic block.

Robert

Just a few thoughts to consider.

SGC

Tim,
I dont know if you know of this site :- http://modelenginenews.org/ , but theres heaps of good info to be found like :- http://modelenginenews.org/techniques/crankshafts.html .
Me I've only got a 7X 12" Lathe and a drll press and a willingness to have a go.
How about something similar(copy) of the VA mk2 , it shows the performance characteristics you stated , just change the case to accept your turbo or a galbrith head, there should be enough VA parts about to get good measurements from.
Stewart

ptulmer

My Feedback: (5)

Robert, hold a chunk of aluminum in one hand and plastic in the other. Aluminum is lighter and stronger. (not to mention far more tolerant to high temps!) The weight comes in with the liner and crankshaft.

Ok Tim, you started this thread. What's your vision?

peterburford

Tim has started it all and Toad has it about right.
Best to just make a few for those involved. Don't get overly ambitious, just yet anyway .
Get together and see what equipment and skills you can round up. You will probably be surprised at what you collectively have.
Agree on a design, draw and specify the parts. Maybe use some from donor engines?
Already you have those with CAD skills to tolerance each part.
They can then be made all over the Country/World.
Each can take responsibility for a task and a completion time.
Keep a running thread on here so that we all can watch the progress.
That would make this just the best and most envied forum.
Peter

digital_trucker

Allow me to add my 2 centavos. Personally, I'd like to see a .049 displacement engine. There's just something magical about that number. I'd also suggest (for the sake of simplicity) using a Cox-style cylinder rather than a liner or the Norvel/AP method. The other advantage of that is that if it BOLTS on rather than threading into the crankcase, you can choose where to have the exhaust point. Where I would see it deviate from Cox is in the use of AAN construction rather than steel/steel. AAC (revlite) should be easily doable if you can get the cylinder type-3 anodized. If you look at the purty user pic by my name, you'll see a render of a concept engine I drew up a while back. I have the full-size render on m home pc and can post it when I get home.

Some material recommendations from the research I've been doing.

2024 aluminum for crankcase and conrod (doesn't require separate bushings)
4xxx aluminum for the piston (resists galling)
6061 should work fine for the rest of the aluminum doodads
Use a tool steel crank with a pressed-in crankpin to avoid having to harden and grind the crankshaft

hogflyer

Here's a thought for a crankshaft - Davis Diesel sells the Killer Crank Cox .049 HD Crankshaft for the reedies designed to survive the diesel conversion. That could solve the issue of a dealing with hardening the crank. And their no that expensive - $14.95. I serious doubt that a crank could be made as tough as that one for anywhere near the cost.

While the throw is for the .049, I think it would be worth while looking at for a .061 engine just for the strength and cost.

Hogflyer

Toad

4132 alum for the sleeve 20% Si alum for the piston, crome the sleeve, DO NOT use a pressed in crank journal, it is easy enough to make a jig to make the crank one piece, pressed in journals dont take a beating for long before the exit stage left.
8620 for the crank, harden it. 2024 alum for the case and bush it, or brg's. 7075 for the rod. backplate 2024 with the rotor 8620 steel, very thin with sealing vanes machined in. Venturi throat with set screws to make changes easy or the use of a carb. is how I would make it.

rainedave

My Feedback: (1)

Since everyone's brainstorming, how about a threaded case that will accept the AP Wasp carb and Cox cylinders? Don't get me wrong, I'm not against the idea of an entire engine. But what if it was developed in stages? The case first, which could be assembled into a working engine as mentioned in my first sentence. Next, a cylinder could be developed that accepts the Nelson/Galbreath or Wiltse Turbo heads.

Bipe Flyer

I would like to see something made from scratch, as per Tim's original idea. I like ABC, or maybe the "Revlite" style cylinders. The Revlite cylinders are hard anodized, right? Isn't that harder than Chrome? Tim, is this process much different from the anodizing that you do?

Andrew

IIRC, the process requires tighter control during anodizing and is more difficult to do consistantly without special equipment. Tim can probably explain better.

digital_trucker

Please don't set it up for Nelson plugs. While they are great performers by all reports, standard glow lighters don't fit 'em. Go with turbo plugs, they're easily obtainable and normal stuff fits 'em.

From the research I've gathered, the only real difference between normal anodizing (type 2, the colorful stuff) and type 3 hard anodizing is that type 3 requires specific temperature controls. Could get creative with a mini-fridge, maybe.

AAN should be super easy to do, just nickle plate the cylinder and use a 4xxx alloy for the piston and you're in bidness.

All sorts of nifty plating things here. The electroless nickle plating system looks just the ticket for AAN.

http://www.caswellplating.com/

Here's that concept engine that I mentioned a while back. Note that the two renders have slightly different exhaust styles.

PlaneKrazee

My Feedback: (14)

I would say toad knows what he's taking about. Excellent choice of materials for thier uses. Would you make the crank a slightly larger diameter and hollow or leave it?

Rick W

My Feedback: (20)

Hey Dave,

Already been there. No intrest and if the price was over $10.00 it was to high, sooo it went by the way side. I build the case, backplate and venturi.

To all involved good luck with the project. If ya get the proto type done, since I have a CNC shop I'll run some parts for ya to help out.

Rick

Toad

I wouldnt hollow the crank, I would relieve it between brg surfaces to .212 dia, keep it short with the pin long enough to drive the rotor. use rotor mass to help with balance, the less moving parts weigh, the easier it is on the parts involved, hence more power to the prop. keep it short and light. the rod will love you for it!

Raymond LeFlyr

My Feedback: (2)

Tim,

Could I have the honor of being your first PAYING customer? I'm not offering to do any prototype testing or anything pre-production - because I'm just not an engine guy (my personal rule is if ya want more speed/power, buy a bigger engine). But I would like to support, and acknowledge, your effort and engine-uity (couldn't resist).

Edit; for what its worth, I would run/fly the engine. I'm not a collector either.

AndyW

My Feedback: (1)

Great looking engine design, Tim.

This was my idea of a new, 1/2A sized engine.

It was created 7 years ago using parts from other engines.

Norvel, (crank and muffler)
AP, (piston+cylinder)
Cox, (throttle carrier and drive washer)
G-Mark, (throttle)

So that makes it a Chinese, Russian, American, Japanese and Canadian hybrid.

The Canadian part refers to a custom made crankcase and backplate mount.

Features include the attached tank complete with clunk.
It can be rigged as a two line or three line setup with muffler pressure to the tank.
The middle deck allows the exhaust outlet to be oriented left, right, rear or even front.

The AP part makes it an AAN engine. Norvel Revlite was tried with no better performance.

Performance is 5K, solid idle with very good transition to 19K on a 6 X 3 black Tornado on 25% Cool Power fuel.

Right now, it's in the hands of a representative of Kyosho in Europe.

Initial assessment was that they are not into small engines. Sigh,,,, []

They pointed out that small aircraft deliver superior performance using motors and LiPos. No mess, No starting issues, especially for newbies, No NOISE. ( me, I LIKE noise).

So now I'm working on a 26cc Tanaka gasser and converting it to glow and diesel.

AndyW

My Feedback: (1)

Digital Trucker,

I really like your design. Agree that turbo plugs are the way to go. I like the idea of a Cox style cylinder that's bolted on, as you show. Make it like Cox but make it cast ally, hard anodized black with exhaust header drilled for a bolt on muffler. This allows exhaust orientation, left, right or back for tuned pipes. Give it three bypass ports.

Don't know about bearings. Did that to Norvels and saw no advantage but was only doing 19K.

Make the throttle WITH AN ADJUSTABLE AIRBLEED.

combatpigg

My Feedback: (3)

After reading the "mission Statement" here, to come up with an engine that is somewhere between a BlackWidow and an AME, it dawned on me that there is one already, the AP .061. What can you do improve on that? I guess my point is to FIRST identify what it is you want to acheive, then decide if it is worth doing. For a one of a kind custom engine, there has got to be something about it that makes it worth the effort and expense. Performance goals need to be put down in writing, X rpm with X prop and these goals can only be met by using existing knowledge of what other engines use to attain that level of performance. Goals need to be realistic, especially where rpm range is concerned. Without complex fuel delivery systems [accelerator pumps, booster venturis, etc.], the high / low speed range can only get so good. I would be happy to see a Revlite COX REEDIE .061 timed like a Big Mig. The liner can be shimmed for port orientation. The wrist pin area should be done like a Cyclon.

PlaneKrazee

My Feedback: (14)

CP,

How is the Cyclon wrist pin area designed?

combatpigg

My Feedback: (3)

SP1, The pin press fits into the rod. The piston has bushed holes for the wrist pin to ride in. I don't think there is a lighter, higher revving and trouble free engine with all these attributes anywhere.

PlaneKrazee

My Feedback: (14)

CP,

Is the Cyclon still available, or better yet is there an engine as light and powerful as a Norvel .074 available?

combatpigg

My Feedback: (3)

The Cyclon is available through Doug Galbreath and through Texas Timers. I don't think there is another engine in the same league as the Norvel .074. Wasn't there also a DF version with about .08 cubes?