Ok so I got this cylinder to play with and found out it had this big stupid plug. After welding a nut to it and slide-hammering it out eventually after some persuasion, it left this big old nasty cavern. Thought, well maybe some kind of lil reed setup will fill the space? Not sure how well this will work, but I'm gonna try and fit a batavus reed block in there, the shape and size just kind of asked for it to be tried out. Wish me luck??
The holes actually meet right up dead center, the only thing is that the Jawas have 5mm studs. Thinking of re-tapping them out to 6mm, there isn't a ton of meat beside the stud holes with the reed block in mind, but I may just go out on a limb and try it out. See how cute this could be? Lil guy might just snuggle right down in there after some VERY careful dremel work :)
Did the deed and tapped both the intake and exhaust out to 6mm, I think there's still plenty of meat now that it's done, after measuring the reed block it doesn't seem like I really need to open the intake up side to side, looking good so far. Using these nifty hex-driven studs, easy to install/uninstall. Time to shape it and get this reed block to fit!
Definitely looks like it has potential! What to the ports look like?
That's an ingenious discovery.
10/10 will watch along
This is top content
I am doing this to a hero kit for puch. Nice work! Maybe I should document work better. Sexy studs btw.
Yeah just port for reeds and it'll rip.
Add boosts at 45deg towards plug and go go go
You could bring it by and we could mill that area flat if you want
Quality stuff
Curious to see what performance improvement you get with this. I looked into this some time ago. I researched and read till I was bleary eyed. From what I read the reed performance depends on the window mod in the piston. Calculating this was way above my experience level. I'm hoping YOU figure this out and share. Go Jawa!
This was one avenue I looked Into. There is a video out there of a shop testing on a dyno the before and after on a Chinese bike engine. They managed to "decrease" performance by adding the reed block.
https://www.ebay.com/itm/174238215514
I think there is a flatter one that could be adapted with a 1/4" standoff and an aluminum plate but I can't find it now. (edited)
Lol
If you don't port for gains yes a reed might not help. I'm
But if you add boosts and 360 intake to the cases you can almost double the power with a good pipe
Window the piston, add a boost and cut skirt to make a new port that feeds into the cases where the skirt was so you don't have to cut cases at all
Big fucking gains
https://mopedarmy.com/forums/read.php?7,4263596,page=1 (edited)
JBOT, you need to educate me on this. Sean and I lust for fast Jawa.
Yes, but it’s a secret right now. Hehe
Ben, you're killing me...
You can throw a reed on anything.
Then port for big gains in whatever power band you want. Pretty easy actually
> Frank Bailey Wrote:
> -------------------------------------------------------
> Ben, you're killing me...
I’ll start a thread when I get it assembled, mounted and running
I have researched porting but the only simple thing to me is widening intake, exhaust and raising the exhaust a bit. Modifying transfer ports and changing timing escapes me. I'm willing to expand my understanding.
Chop big hole in intake side of piston and add boost ports that go into the intake on the cylinder. Piston port cylinders can have boost ports too but they should not go into the intake. Piston ports can also have holes on the intake side of the piston, but they likely close the top and bottom of the cylinder/crankcase as they cross they intake port.
> Frank Bailey Wrote:
> -------------------------------------------------------
> I have researched porting but the only simple thing to me is widening
> intake, exhaust and raising the exhaust a bit. Modifying transfer ports
> and changing timing escapes me. I'm willing to expand my understanding.
Vlado Vlado the jawa gurus Reed setup + other goodies https://mopedarmy.com/forums/read.php?1,3056166,3059005,flat=1#msg-3059005
You could maybe use those adapter plates I had made for V1 to slap a malossi Reed block on this thing.
On V1 polini even without modifying it the reeds make it quieter and spit less gas while not decreasing performance
But what the fuck is the deal with the plug
this thread needs updated pls
^^yeah another lost moped project that lost interest, put on the back burner and time is just reeding away...
Sorry dudes I had to give my reed block away to someone who needed it, waiting for em to be back in stock so I can get back on this! It’ll go back to the front burner soon!
I'm working on something very similar. Putting a Batavus reed block in a 210 cylinder. I did a little port work to the cylinder trying to copy a Puch Polini cylinder. I will cut some channels into the cases to match. I might widen the channels in the cylinder towards the center but not sure yet. Also not sure if I will go with two slots in the piston or one large window. I still need to relocate the exhaust studs so I can open up the exhaust a bit too. I will probably also cut a port from the front of the intake port forward into the transfer port area.
very interesting
keep posting the progress please!
I added some ports forward of the intake port and carried the ports into the cases.
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