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Homemade reed valve

Posted: Thu Jan 21, 2010 4:07 pm
by skip1701
Hi all, noob question here. Is it possible to make your own carbon fiber reed valves and is there any performance/reliability gains in doing this? I have access to a full composite shop and can make any thickness and or shape here. If its worth a try. Any help would be appreciated. (Ahh ,the joys of working in the aerospace industry!)
Thanks
Skip

Re: Homemade reed valve

Posted: Thu Jan 21, 2010 4:44 pm
by turtle13
skip1701 wrote:Hi all, noob question here. Is it possible to make your own carbon fiber reed valves and is there any performance/reliability gains in doing this? I have access to a full composite shop and can make any thickness and or shape here. If its worth a try. Any help would be appreciated. (Ahh ,the joys of working in the aerospace industry!)
Thanks
Skip
you may want to PM wheelman about this, he has been handmaking some reeds for a while. i know people want them, but there are not a huge amount of demand outside of the dio reeds. all of that aside, i want a set of 85 aero 50 reeds!

Re: Homemade reed valve

Posted: Thu Jan 21, 2010 6:33 pm
by bakaracer
yes you can make your own carbon fiber reeds. malossi and polini sells it in sheets so you can cut your own.the 3 thicknesses they sell are the 0.25mm,0.30mm,0.35mm thicknesses.

Re: Homemade reed valve

Posted: Thu Jan 21, 2010 10:08 pm
by Wheelman-111
Greetings:

Get the finest weave of high-modulus carbon carbon cloth you can find. Carbon has the spring you want but cracks easily when point-loaded, as you probably know. Put 2-3 layers on both sides of a layer or 2 of 4-ounce fine-weave Kevlar. This material supplies the resilience that the carbon lacks. Saturate with West System or System 3 slow cure epoxy, using as little hardener as possible to get a cure in 48 hours. Place between waxed glass blocks and squeeze the snot out of them in a shop press. The longer it cures, the better. Play with the layers to get .35mm final thickness. Omit the center split making a Mono-reed.

Use a fine carbide bit in a Dremel or RotoZip tool to finish the edges. You can't drill the screw holes with a twist drill - only carbide Dremel cone. Do not over-tighten the reed stop screws. The result should outlast your piston rings.

I may have a set or 2 of prototypes for '86-'87 Aero 2-petal rectangulars, maybe 1 for SB50/'85 Aero. Ugly because I left Kevlar exposed on 1 side, but they work fine.

Re: Homemade reed valve

Posted: Thu Jan 21, 2010 10:41 pm
by Kenny_McCormic
I wanna see what 2 stage reeds will do for a spree.

Re: Homemade reed valve

Posted: Fri Jan 22, 2010 3:44 pm
by skip1701
Thanks folks. I just happen to have those weaves available and the kevlar too.I can put the cloth between some kaul plates and vacuum them down in our oven. I guess I should just copy the stock valve. Would it also help to clean up the intake manifold and any high points or casting flashing ? What will these mods do for my stock 87 se50. I've also swapped to a cone type air filter. What jets should I use ? I'm just playing with this scoot, the next one I'm gonna do as many mods as possible.
Thanks to wheelman and everyone else,I'll let you know how it goes.
Skip

Re: Homemade reed valve

Posted: Sat Jan 23, 2010 9:29 am
by elitedio
I have made a lot of bagged and wet lay up composites. I have always used 5-15 oz fabrics with carbon. and 5 oz kevlar. I do think that the kevlar is important for two reasons. If it breaks its threads stay intact and it is a lot more flexible that carbon which by comparison is brittle.

I am impressed that wheelman makes his own composite and is successful doing it. I would figure that once your engine starts ingesting little chunks off the reed and you start looking at the scratches that you put inside the engine when you tear it down you may realize that this is would have better been left to others who have engineered it a million units before.


If I were to make some I would try using a sheet of plate glass and apply some spray mold release and start with one sheet of the thinnest carbon, wet it out and then a layer of kevlar on the bias. I would cover it with rip stop nylon and some batting and put it in a bag and vacuum it down.

Once cured you can peal it off the glass, measure it's thickness. I would shape it using a stock reed as a template. drill the holes. Another layer is going to make it get stiff fast.

I have used carbon, fiberglass and flox to modify my scooter bodywork. I am pretty happy with that use. It is structural but not a critical application.

I also do not have a curing oven and use west epoxy system, My construction is to make single parts.

Re: Homemade reed valve

Posted: Thu Feb 11, 2010 12:01 pm
by elitedio
Wheelman:
I just remembered something that may be of interest to your home brew reeds. A couple of years ago I was looking for a way to coat a fuel tank on a motorcycle. I had some West System epoxy in my shop and thought about using it. My wife being more cautious than I suggested that I call their tech line and see what they say.

The gist of what I was told by their engineer was to not use West systems epoxy in a fuel tank. He told me that they put a block of epoxy in a container of fuel for 6 weeks and it gained 16% weight. He said that they didn't analyze it further as it was obvious it was not working. He recommended using KBS fuel tank coating which I did. KBS never get stiff however and remains somewhat flexible It would not work as substrate for carbon.

Reeds are not immersed in fuel but they are in contact with gas. I take it that you do see some deterioration over time.

West Weight Gain

Posted: Thu Feb 11, 2010 12:58 pm
by Wheelman-111
Greetings:

I had a set of reeds go about 1000 miles in Flash I. This was an early layup before I knew what thicknesses and fiber layup worked best. I'm almost sure it broke mainly because of the thin/brittle low-mod. carbon I had at the time, not due to resin failure.

I appreciate the insight from West. I've used that product as well as System3, which I have little reason to believe is substantially different from the former. The weight gain of hydrocarbon block in hydrocarbon fluid is disturbing but not entirely unexpected. It sure doesn't sound like a good thing, but I'm not sure it automatically translates into degradation of structural integrity when there's carbon and Kevlar - mainly - in the laminate. I'll sure consider your remarks if/when I decide to get back into home-brewed petals. Thanks again!

Re: Homemade reed valve

Posted: Thu Feb 11, 2010 1:26 pm
by bradthreee
skip1701 wrote: What will these mods do for my stock 87 se50. I've also swapped to a cone type air filter. What jets should I use ? I'm just playing with this scoot, the next one I'm gonna do as many mods as possible.
Thanks to wheelman and everyone else,I'll let you know how it goes.
Skip
Basically carbon reeds give "crisper throttle response" or a little more peppiness.
I've found that the Uni foam filter worked best in my application as a cone type filter would get saturated in fuel and "choke" the motor of air causing it not to start.
As for the Jets, its something that is a trail and error thing. Buy yourself a jet kit. Start the jets high and check your spark plug after a few minute test runs @ WOT. Remember that rich is better than lean in this instance. Compare your plug to this chart: http://www.dansmc.com/Spark_Plugs/Spark ... talog.html

Re: Homemade reed valve

Posted: Thu Feb 11, 2010 2:24 pm
by Clivester
elitedio wrote: I also do not have a curing oven and use west epoxy system, My construction is to make single parts.
Maybe the heat-cured prepreg type carbon fiber fabric would be better? I understand that the heat-cured epoxies are more fuel resistant.

Re: Homemade reed valve

Posted: Thu Feb 11, 2010 7:16 pm
by elitedio
yeah prepeg could very well be the ticket. I am sure an industrial pressure oven would be needed. It's beyond my home brew stuff.



clive sez:
Maybe the heat-cured prepreg type carbon fiber fabric would be better? I understand that the heat-cured epoxies are more fuel resistant.