How about a moncarb manifold out of fiberglass or carbon fiber?

[chuck c]

Has anyone tried it? Making the molds would be quite a bit of work, but then producing copies would be a snap. They could be far less expensive than a metal one. Easy to paint and would not draw heat out of the flow and carb like aluminum does. What do you think?

 

[joedrum]

cm 85 talking stuff in that direction over at saunders site ... but he has a lot of talk and much in reality to back up his talk really IMHO ....i think the oldwing market cant really support a buisness venture its a srinking market along with most oldwingers funding ...mine for sure ... that why most of this is grass roots tech ... its what works mostly here in this enviroment

 

[Omega Man]

A 3-D copier would make the job simple. I wonder if there are places that one could take the plans and they would produce it?

~O~

 

[chuck c]

Reproduce parts is what I do. The place I work repros oil pans, radiator and brake lines, etc. in stainless steel. I was able to measure my carb assembly here and when I get the design done we'll crank it out. BTW, which do you think would be better, stainless steel or aluminum?

I do know a bit about 3D printing too. You could make a model from which to make molds with one but it wouldn't be cheap. Probably cost a grand.

 

[chuck c]

joedrum » Thu May 08, 2014 11:42 am[/url]":k0uxa51l]
cm 85 talking stuff in that direction over at saunders site ... but he has a lot of talk and much in reality to back up his talk really IMHO ....i think the oldwing market cant really support a buisness venture its a srinking market along with most oldwingers funding ...mine for sure ... that why most of this is grass roots tech ... its what works mostly here in this enviroment

Yeah, you're probably right. Not much demand to justify the setup for mass produced parts. And if there was, somebody would be able to undercut me.

 

[Omega Man]

[video]https://www.youtube.com/watch?v=DE7c7oIBUNQ[/video]

Did you see it at 3:05? It would work.

~O~

 

[mcgovern61]

Sure looked like a carb manifold!

 

[slabghost]

I don't know about carbon fiber. But fiberglass gets brittle at low temperatures. And if not protected does break down over time with exposure to the elements. As stated this is a shrinking market with more oldwings getting parted out every day.

 

[chuck c]

Sure you can make one with 3D printing and it should probably hold up well enough to test. The more complex the shape, the better 3D is. However the plastics used have limits for heat, cold, chemical resistance, etc. that while pretty good would not last long in service. An intake manifold is a really nasty job for plastics as it gets all of the above! Not only that but some of the 3D printing methods leave the parts slightly to very porous. It would be the #1 way to make a prototype, that's for sure.

 

[chuck c]

When 3D printing started in the late 80s machines cost a few hundred grand there were only used by a few big companies like car manufacturers to test fit plastic parts before spending $100,000 on a mold. The first use I heard of was the air ducting for the heat and AC inside the dash. Imagine trying to design those to fit in there, and scrapping $100,000 mold if it doesn't fit or a change is made. It doesn't take much of that to justify a machine that costs as much as a very nice house!

 

[gwhawg]

I saw on utube a manifold made from PVC pipe. Seemed to run good owner said he had it on the bike for 10 years with only occasionally resealing it with silicon

 

[chuck c]

Yeah, quite a few guys have made them with PVC that way and they work. I'm seriously considering making one that way to test a few things like runner diameter before making one in metal. PVC has another advantage: it's a terrible heat conductor. It would not act like a big heat sink to draw all the heat out of the fuel/air like aluminum does. You can by it in sheet and plate too, you're not limited to only pipe.

 

[dan filipi]

chuck c » Fri May 09, 2014 3:24 am[/url]":33r9t3aa]
Yeah, quite a few guys have made them with PVC that way and they work. I'm seriously considering making one that way to test a few things like runner diameter before making one in metal. PVC has another advantage: it's a terrible heat conductor. It would not act like a big heat sink to draw all the heat out of the fuel/air like aluminum does. You can by it in sheet and plate too, you're not limited to only pipe.

Hmm,
The process of picking up heat while under a vacuum causes the fuel liquid to vaporize which is what we need to take place.

PVC is a good tester before building out of metal like you say.

Don't believe everything you read about these manifold builds.
One guys idea of 'working' can be VERY different than a functional build that idles and accelerates smooth while getting acceptable gas mileage.

 

[chuck c]

dan filipi » Fri May 09, 2014 9:03 am[/url]":3au2std4]

chuck c » Fri May 09, 2014 3:24 am[/url]":3au2std4]
Yeah, quite a few guys have made them with PVC that way and they work. I'm seriously considering making one that way to test a few things like runner diameter before making one in metal. PVC has another advantage: it's a terrible heat conductor. It would not act like a big heat sink to draw all the heat out of the fuel/air like aluminum does. You can by it in sheet and plate too, you're not limited to only pipe.

Hmm,
The process of picking up heat while under a vacuum causes the fuel liquid to vaporize which is what we need to take place.

PVC is a good tester before building out of metal like you say.

Don't believe everything you read about these manifold builds.
One guys idea of 'working' can be VERY different than a functional build that idles and accelerates smooth while getting acceptable gas mileage.

A vaporizing liquid takes heat away, just like sweat or air conditioning, so gas making the phase change from liquid to vapor is acting just like one of those to cool the carb and manifold. If it cools enough and there is water present in the fuel or the air, it will begin to freeze and the gasoline will condense into droplets just like fog or rain. Heat will counter that to keep the water and gas far above its condensation point. That's the low end, the minimum we need. The warmer it is, the easier it vaporizes, up to where it begins to boil, which from what I've found can be anywhere from 100F to 400F depending on the octane and a dozen other variables. Conversely, cool makes a denser charge so more gets into the combustion chamber each fill.

SO..... we want it to be warm enough to vaporize easily and completely, not so hot it boils, then cool to get the maximum charge in without it condensing into mist. Easy!

 

[slabghost]

Okay let me clarify this again. We want the fuel to atomize and flow with the air. The carb does this metering out a fine spray. Vaporized fuel is evaporated fuel and far less dense. Increasing the airspeed through the carb causes heat loss. Fuel vaporizing in the process also causes heat loss. Metal manifolds unless under 50 degrees or there about do not draw heat from the mix. Quite the reverse. The mix draws heat from the manifold causing the manifold to get colder.

 

[chuck c]

That's pretty much what I said.... the mix going thru draws heat out of the metal around it.
You're using the terms "atomized", "vaporized", and "evaporated" and I don't see much practical difference between them. The bottom line is to try and get the fuel broken down as fine as possible and thoroughly mixed with air. Heat helps that process, lowering the vapor point of gas. At the same time the mix flow is absorbing heat from everything it gets near. When that metal gets below freezing gas will still vaporize but any water won't. We need to keep the flow at least warm enough to not reach 32F, more is better up to some point short of boiling.

 

[dan filipi]

I have studied this enough to know that vaporized fuel is needed.

Here's an article that explains how Charles Nelson Pogue achieved phenomenal mpg by completely vaporizing and drying the gas before it's introduced into the engine.
https://fuel-efficient-vehicles.org/ener ... age_id=986

My brother and I built a vaporizing chamber when I was 16 and had a V8 idling off of it.
We quit when we had a flash back and blew part of it apart.

 

[Ansimp]

Interesting stuff Dan. Too bad the website background makes reading it all horrible.

 

[chuck c]

Fascinating! I heard of this in the 70s but not all the specifics. This is an urban legend that's mostly true. Pogue said the wild claims of what it could do were exaggerated by newspaper men- fancy that. He's a good quote that pertains to this thread:

To provide a perfect gas-air mixture for the engine, Pogue believed that a heating chamber was needed to thoroughly vaporise the gasoline before it joined the air stream and entered the cylinders.

Although automobiles do have a heating chamber built into the intake manifold, this chamber heats the gasoline and air mixture only after it leaves the carburetor Although this helps the automobile to start easier and warm up faster, it also creates an expansion of air and consequently, a smaller charge of air-gas mixture is drawn into the cylinder. Pogue decided that the only way to produce a real gasoline vapour was to heat the gasoline and not the air.

His carb used engine heat through 2 heat exchangers to completely vaporize the gas before it gets mixed with air. His is kind of complicated. I wonder if a modern version could be made simpler. It doesn't seem to be very good for the widely varying needs of a vehicle carb but would kick butt feeding a generator that runs at constant speed.

It's a good trick to pump the gas vapor fast enough and meter it to match the demand. Think what could be done with modern controls.

There is one other possibility, you know. Convert to propane. It's not crazy, there are kits out there to convert small engines. Carry a 25lb can on the back and a small camper bottle as reserve! After I get the monocarb working.... I might have to try this.

 

[chuck c]

Ansimp » Fri May 09, 2014 6:04 pm[/url]":118gl3sc]
Interesting stuff Dan. Too bad the website background makes reading it all horrible.

Yeah, I had to select all text and magnify it. Select all changes the color and covers the background.