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Joined: Nov 2010
Posts: 106
Apprentice level 2
Hi Guys, I know ive been a bit quiet lately but had some personal family issues to deal with.
Well ive almost finished my C12 restore, Had to drop the electronic ignition as it was faulty and put in new points and condenser, rewired the kill switch which was shorting somewhere, Just in the process of tuning her up and waiting on the logo's to be completed then she will be finished.
I have uploaded the photo's to photo bucket for you all to have a look at. I was going to take some as it is now photo's but my camera has died the shutter wont open so when my daughter gets home from work i will borrow her camera and upload them.
By the way i took her outside for the first time yesterday and she started on the second pull i couldnt believe it god knows how long this engine has been lying around in someones garage but i estimate her to be around 1955.

Also note the individual wheel height adjusters which would have been a pain to do, you would loosen each wheel nut adjust height and tighten back up. Height adjusters have come a long way since these ones.

Have a look at the photo's and let me know what you think.
Cheers
Pete

http://s1128.photobucket.com/albums/...ore/?start=all

Portal Box 6
Joined: Jul 2005
Posts: 6,362
Likes: 10
Administrator - Master Technician
****
Hi Pete, unfortunately the link won't work for me...if you have the pics in your computer, you can upload them directly to a post using the site uploader just click HERE for the instructions...You will note Pete there is a maximum size allowed 4Mb, and must be in jpg. or png. format. If they are not, don't fret...you can download a free image converter...just google image converters.
Can't wait to see the pics Pete. grin
cheers2


Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin


Joined: Nov 2010
Posts: 106
Apprentice level 2

Joined: May 2011
Posts: 2,738
Likes: 6
Forum Historian
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Pete, Would it be ok if I brough some of these across directly into this thread for archival purposes, Photobucket links have a habit of dying over time.

I have a bit of free time to bring them over if you are ok with it.


Cheers
Ty

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Joined: Jan 2009
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Pushrod Honda preferrer
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I like the reed valve layout Pete - look forward to getting at least some of the pics onto Outdoorking and discussing it - especially if you have some pics of the reed valve, carburetor and intake system. I'd like to see the inside of the crankcase with the base removed, so we can see how they are keeping the intake area clear during the compression stroke.

Joined: Nov 2010
Posts: 106
Apprentice level 2
Originally Posted by Mr Davis
Pete, Would it be ok if I brough some of these across directly into this thread for archival purposes, Photobucket links have a habit of dying over time.

I have a bit of free time to bring them over if you are ok with it.

Hi Mr Davis,

Sorry for the late reply for some reason i didnt get any email notification saying there had been replies, I thought i was automatically put on a watch list once i started the thread.

Anyway, sure go for your life with the photo's i have no problem with you archiving them, take as many as you like.
Pete

Joined: May 2011
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Wonderfull, I'll get onto that tomorrow, and get some up here!


Cheers
Ty

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Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Joined: Nov 2010
Posts: 106
Apprentice level 2
Originally Posted by grumpy
I like the reed valve layout Pete - look forward to getting at least some of the pics onto Outdoorking and discussing it - especially if you have some pics of the reed valve, carburetor and intake system. I'd like to see the inside of the crankcase with the base removed, so we can see how they are keeping the intake area clear during the compression stroke.

Hi Grumpy,
are you looking at the right mower mate because the reed valves aren't showing in any of the pictures. I just looked through my pictures and i have some of the carby dismantled a bit but the reeds are showing, dont have any with the internals though sorry. [Linked Image]
[Linked Image]

Joined: Jan 2009
Posts: 6,926
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Pushrod Honda preferrer
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[Linked Image]
This picture shows the basic layout Pete, with the intake directly into the bottom of the crankcase (there is no piston-controlled intake port with a reed valve engine, because the reed valve does the same job better). The one you've just posted gives us a good look at the reed valves themselves. To complete the illustration of the way it works, I was hoping you'd have a picture of the inside of the crankcase, taken through the opening where the carburetor and reed valves attach, with the piston on the way up, so we could see how much room there is for the mixture to go in despite the crankshaft counterweights being in the way. However if you don't have that picture, that's OK, I'm just glad you captured the ones you've shown us. There is very little reed valve information on Outdoorking.

Joined: Nov 2010
Posts: 106
Apprentice level 2
Hi Grumpy,
I'm not sure if these pictures taken from the manual and parts list will show you or others how the reed valve works i'm sorry this is all i have.
Yes by all means put pictures up from my site if you want, help yourself they are for all to see.
Pete


[Linked Image]
[Linked Image]
[Linked Image]
[Linked Image]
[Linked Image]
[Linked Image]
[Linked Image]

Joined: Jan 2009
Posts: 6,926
Likes: 10
Pushrod Honda preferrer
***
Thanks Pete, what I was trying to get a feeling for, is how the incoming air/fuel mixture gets into the crankcase, because the crankshaft counterweights are passing the reed valves at the time it has to happen. As the diagram shows, because the reed does not open very far (it has to bend, not pivot, to open at all), the main limitation on induction efficiency is the small opening area of the valves, not the presence of the crankshaft counterweights:

[Linked Image]

I've said before on Outdoorking that reed valves are great for improving scavenging, especially at low speed, but they really mess up the volumetric efficiency. Nice for a low speed 2 stroke, though, because it helps it run more smoothly.

Joined: Jul 2005
Posts: 6,362
Likes: 10
Administrator - Master Technician
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Hi Grumpy, back in 1963 I was, with my uncle, into go-karting and we used McCulloch engines which were a high speed application using reed valve carbies....Here is a pic if the MC 70.

[Linked Image]
cheers2



Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin


Joined: Jan 2009
Posts: 6,926
Likes: 10
Pushrod Honda preferrer
***
I recall people using McCulloch chainsaw engines on gokarts in those days Deejay, but I hadn't realised they were reed valve. It seems an odd way to go, but it was a long time ago. What I've read about the rationale seems to hover between "that was before we developed good port-controlled designs", and "reeds give better low speed torque and in special cases, a narrow-band boost at medium speeds". My current thinking is that they do have something to offer where low speed torque is important, and any weakness in high speed power can be overcome by making the engine bigger. Lawnmower engines may be a good application, since I think users like to hear the engine running decently across a range of speeds and loads, and I've never heard a Victa engine, in particular, do that.


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