Best material to make a reed valve out of???
 

My previous attempt at making a reed valve worked....but only for a short time. Metal fatigue set in after about 2 minutes of run time so I am thinking that the material I used was not adequate for this use.

I would assume that a thin, high-carbon spring steel would be the best choice as well as fiberglass or carbon fiber. I've seen ready made reeds online that I was hoping I could trim to fit but since I can't seem to find any dimentions I don't thinkI can go that route.

Any ideas here guys?

Richard

RE: Best material to make a reed valve out of???
 

Spring steel would be the best choice.

RE: Best material to make a reed valve out of???
 

How thick on that spring steel? Thanks Capt,n

RE: Best material to make a reed valve out of???
 

The steel I used was .042". Seemed thin enough but I don't think it was actually spring steel. Couldn't take the flexing. Had multiple cracks at the flex point. Luckily nothing broke off. I guess it was a good thing I checked after a little running to see how it had held up.

Now here's the $64,000 question: where would someone find spring steel thin enough for a reed?

Richard

RE: Best material to make a reed valve out of???
 

Just a quick comment.....most(if not all) reed blocks I've seen have some sort of backer plate to keep the reeds from flexing too far,so they don't create the kind of cracks you're describing....did you have such a backer? I saw nothing of it in your earlier thread....

RE: Best material to make a reed valve out of???
 

www.mcmaster.com
#9503K13
Blue-Tempered Spring Steel Shim Stock Roll .004" Thick, 6" Width X 50" Length
In stock at $18.27 Each

RE: Best material to make a reed valve out of???
 

Thanks. I'll take a look at that.

No I didn't mention any backer but I did add one...sort of. A short strip of AL. The cracks weren't at the edge where the backer was though. They were just at the very edges of the reed about 1/8" in from the backer. I figure this is where the most flex was going on.

I'll look into the sping steel and see what I get. I FINALLY found a local small engine place that carries Poulan parts that doesn't insist on a part # or model number to help me. The fellow told me to just bring in the parts I need and he'll find something that will work. Some of the people I've been calling are acting like they're doing me a huge favour by even answering the phone. I actually asked one guy why he was making it so hard for me to give him my money. He didn't get it. I'll deal with not having the parts I need for a while longer if it means I won't have to work with a person who does not value my business.

Seriously, who would throw away a $25 sale just because they may have to check a few parts for fit before the sale? It's not like I don't intend to buy from the same place again.

Richard

RE: Best material to make a reed valve out of???
 

I know what you are talking about on that number bit. About half the chainsaw dealers want that number or they will not talk to you. When I made up my Homelite 30, I found the perfect guy that knew all the interelationships of the Homelite Whackers. He fixed me right up. No numbers.

Here is a link http://www.lawnstation.com/ On this site, you can go to the Poulan factory page and then pull up all the parts pictures of the current models. A PDF style parts book takes a while to load. On DSL they take probably 40 seconds

Enjoy,

Jim

RE: Best material to make a reed valve out of???
 

It has been 20 plus years but reeds for motorcycle engines used to be stainless spring steel. When reeds were modified the racing people often used fiberglass reeds. When ingested the fiberglass reeds did less damage to the engine. A cart racing shop might have the needed material.

Bill

RE: Best material to make a reed valve out of???
 

www.mcmaster.com

Stainless steel #318 X .004" $17.73 But what grade stainless. 3-18, 304, or ?.
.005" G10 # 1331T23 $7+

Enjoy,

Jim

RE: Best material to make a reed valve out of???
 

just a quick note about Stainless Steel.... many people think it's the best thing since sex... but it is overused and abused.... it makes lousy knives and even worse springs.... carbon steel, though prone to rust is MUCH better as a spring and also makes the best of knives...

[:-]

RE: Best material to make a reed valve out of???
 

w8ye, that link was simply BRILLIANT!!!! I actually think that I have found both the model number of the saw and the actual part numbers for the reed and reed stop. I'm going to check with a shop (one last time) to see if they can help me know.

Thank you very much for the help.

Richard

RE: Best material to make a reed valve out of???
 

Has anyone ever tried useing the reeds from a bike shop, say from companies like Boyseen and such. I ran them in my dirt bike years ago and boy do the wake up the power band. Just a thought ...

RE: Best material to make a reed valve out of???
 

I did think about those but all the ones I've seen seem to be split reeds with 2 reeds per side. I don't think they will fit the area that I need to cover and no one seems to be able to provide the dimentions for their reeds so it's hard to tell if they'll be big enough.

I have worked on 50cc moped and scotter engines quite a bit and the reeds are typically on blocks with 2 reeds per side. Overall they allow quite a bit of air through but each reed itself is considerably smaller than the one that I'd need for this 33cc.

I do have a high performance bike shop near my work. Couldn't hurt to head down there after work sometime this week and at least see if any fit. I'd sure rather buy one that's just about right and maybe trm to fit than make a whole new one from scratch.

Richard

RE: Best material to make a reed valve out of???
 

how about the standard feeler gauges we use to gap spark plugs.you get a lot of choices,already numbered,about the same size as the ryobis.

RE: Best material to make a reed valve out of???
 

Actually ahead of you there. I looked through all the feeler guages I have at home and could find at the hardware shops\home depot\auto parts etc and none of them are wide enough. The best fit was almost 1/4" too narrow. I'm still a little leery of going with metal. After seeing the cracks in the one I made I don't want to risk the engine with a homemade one. If I go with metal it'll be a stock piece.

I'm planning to go to a bike shop sometime next week and see if they have a reed that I can use with little trimming. Had to put this project on the back burner for a while. Too many projects to do around the house and I finally have the weather to do them...at least my wife thinks so.:)

I've got some vacation time coming up in a few weeks so I'm hopefull to get it done then. I still have to finish the project this engine was intended for anyway so it's not like I'm in a real hurry to get the engine done.

And now I picked up (yet another) engine that looks like it'll need less work but I don't think it's going to have the power I need so I'm debating if I'm going to put the time in yet.

All this is for a 21lb airboat so I need to have enough thrust to pull it from a dead stop on grass. I don't think the newest engine will have what it takes. I don't intend to be running on grass but I'd like to make sure I have the power to move regarless of the surface I'm on.

I'll post more if\when I finally get things moving.

Thanks all for the ideas.

Richard

RE: Best material to make a reed valve out of???
 

Just an FYI...

the dirt bike and water craft guys have been using fiberglass (like g10) since the late 80's. they last a long time, and respond better than any metal. (becasue they are lighter) But... you do have to run a backing plate so they don't over flex.

RE: Best material to make a reed valve out of???
 

Get a floppy disk. Remove the metal from the disk. shape your reed. I have one in a Ryobi 31 that is just perfect.

Tim

RE: Best material to make a reed valve out of???
 

ummmmmm..... there's no metal in a floppy disk..... the disk itself is mylar, and AWFULLY thin and "floppy" :D

[:-]

RE: Best material to make a reed valve out of???
 

I LIKE THIS IDEA!!!!!!

And being in the computer field I think I can come up with a few of these.:D

I think I can even use one of the test reeds I made up as a backer to keep it from over flexing.

Thanks!!!

Richard