Kymco SC10AS 100cc and beyond:

[oldgeek]

Nov 23, 2018 10:50:47 GMT -5 Lucass2T said:

How about adapting the stock head for a combustion chamber insert? Then you're not stuck with stock dimensions and you can use the stock cooling fins as some sort of 'crown' to clamp the combustion chamber insert to the cylinder.

Interesting, gonna have to think about that idea.

[oldgeek]

Inspired by some vids this weekend, I tried out some ideas tonight. This was just a trial using a stock head to see if it will work. Using my plasma cutter I think I came up with a way to make a hole in the router template most any size I need for this project. I will post pictures of the process when I finish making the jig used to cut the holes.

For now, here is how it will work, the pictures should help explain what is going on. I do not have the right burrs yet, I just used what I had on hand to test. I need to order one with an 1/4" shank and a profile like this SC-3NF 

I just used this 1/8" shank burr to show how the bit will ride against the template. The router I will be using only holds 1/4" shank burrs.


The plywood is used as a riser so the router base will clear the 4 bolt heads holding the template in place.

Here is how the whole rig sets up.

This is what it can do.


I think with the correct burrs I can get the combustion chamber shaped. Figuring out how to cut the squish band is another problem. I am thinking I will make some type of holder for the head so I can chuck it up in some type of poor boy lathe or drill press.

[190mech]

I have one of those cutters at the shop,dont like it,cuts aggressive and chatters when hand held.My choice would be the single cut for steel,well lubed to keep from packing up..If I can find that alu burr at the shop,can send it to you if you like..

Edit,Found it!

[oldgeek]

Nov 26, 2018 6:57:16 GMT -5 190mech said:

I have one of those cutters at the shop,dont like it,cuts aggressive and chatters when hand held.My choice would be the single cut for steel,well lubed to keep from packing up..If I can find that alu burr at the shop,can send it to you if you like..

Edit,Found it!

Put it on my tab! Lol

[oldgeek]

I adjusted the bit and took some more meat out of the combustion chamber. It came out pretty good I think. The void currently holds roughly 9cc. If I can figure out how to get the squish band extended out to the 50mm scribe mark and the whole thing decked a bit, I am done!
I am currently working on a jig to hold the head so I can spin it

[190mech]

Looking good!After the bowl cut is there still enough aluminum left for heat to transfer to the fins?Once the squish is cut the volume should be real close!!

[oldgeek]

Nov 26, 2018 18:01:51 GMT -5 190mech said:

Looking good!After the bowl cut is there still enough aluminum left for heat to transfer to the fins?Once the squish is cut the volume should be real close!!

Plenty of meat left there IMO. This stock head is pretty thick.

[oldgeek]

This took a lot longer and was a lot harder than I thought it would. Took most of the day and a couple trips to the hardware store to finish the jig. Then I spent the whole evening trying to get it to run true. I tried everything, even both hammers Lol! Only when I gave up and was about to head home it decided to run pretty true. So I stayed a while longer and cut a little of the squish band. I just pulse the motor about every 10 seconds and hold a section of a razor blade to scrape while it spins. My hands started cramping so I quit for the night.

I made a little progress, but there is still a ways to go.

[SMALL CC TEK]

Nice job nice .. Do you have a mill and a rotary table? Just a thought cheap rotary table and vise make a mount for you you dremel or whatever cutting tool you using . Set the angle of the bit with your jig cut your head rotating the table
manually oil and cut etc nice job . Your thinking outside the box and making it work nice

[oldgeek]

Nov 27, 2018 23:53:05 GMT -5 SMALL CC TEK said:

Nice job nice .. Do you have a mill and a rotary table? Just a thought cheap rotary table and vise make a mount for you you dremel or whatever cutting tool you using . Set the angle of the bit with your jig cut your head rotating the table
manually oil and cut etc nice job . Your thinking outside the box and making it work nice

Yeah I kicked around the idea of a cross slide mounted to my turntable to make centering the head easier, but decided against paying $100 for chinese precision. A cross slide with a built in rotary table from Grizzly is $400+ but that is not in the budget. Plus I still would need a Z axis to bring the cutter down into plane.

After much thought, the best solution I could come up with is finding a stock Piaggio head. They have a straight spark plug hole should be easier to mod using a lathe. But I do not have a stock piaggio head or a lathe, so I went down the road I am currently on.

I hope this comes out good enough to use when I am done with it.

[90GTVert]

Nice work getting this done by any means necessary. You're quite good at coming up with jigs and rigs for various bits of engine work. Cool to watch.

[Lucass2T]

Nov 28, 2018 22:18:12 GMT -5 90GTVert said:

Nice work getting this done by any means necessary. You're quite good at coming up with jigs and rigs for various bits of engine work. Cool to watch.

Thats what i noticed too! Things i myself wouldn't necessarily think of first thing. Good work OG!

[190mech]

Scootopia wish list; Lathe,,TIG...

[ryan_ott]

Everyone could use a baby giraffe. It’ll be my next purchase.

[oldgeek]

Thanks everyone for the kind words! I enjoy working on my 2T scoots, they help to keep me out of trouble. I get a lot of satisfaction riding them. I like to surprise people, nobody expects a 50+ year old 300lb man on a POS looking scoot to rip past them going 50+mph brr-aaa-pppp! It never gets old seeing the look on their faces, no matter whether they are laughing, or jaw dropping!