batavus third transfer?

shit talkin' hippy /

ok, so I realized that I had buried this idea way too deep in a slightly unrelated thread and so nobody would probobly find it, I'll repost it here.

*

The batavus has like 70% of its bore unused on the top half of its jug

Re: batavus third transfer?

it has been done and it works.

you sir are correct

Re: batavus third transfer?

so rafter care to post any pics?

Re: batavus third transfer?

shit talkin' hippy /

so is an open transfer ok? like in the early puch cylinders?

I guess so since it's never really uncoverd by the piston any deeper than where the normal ports cut off... it just would increase crankcase volume and mess a little with primary compression, but that's probobly good since if another transfer is being added than a larger carb would help out alot and that extra case volume would benifit from the larger carb... brainstorm sorry...

I guess the only real questions I have are:

Should I do something with the piston skirt? (I'm thinking not since it'll just be static metal in the case moving back and forth with an open port)

and:

should I point the stream of the transfer at the head(squish band) or piston crown? (I'm guessing head since I'd just be tossing unburnt fuel out the exhaust with the port facing the piston) maybe two ports that point and converge streams aimed at the head to slow the velocity of it heading too fast out towards the exhaust?

I want to look at a three port cylinder that works well and see how it was aimed I guess...

Re: batavus third transfer?

Dude, read Jennings on loop scavenging. Totally made me re-think the function of transfer ports.

Re: batavus third transfer?

shit talkin' hippy /

yeah, I read that and A.G. Bell's so I guess I'll just go off of what I think I know. I was just seeing if anyone had done this before

Re: batavus third transfer?

shit talkin' hippy /

Plus this is how much space the there is between the head and piston at TDC! thats crazy! (normal I guess?) I guess I should mill down the jug since even if I were to make the head completely flat there would be no compression to speak of... new rings and it only has 95 psi.

Re: batavus third transfer?

if you mill the head almost completely flat you will have around 180 psi (i have 183) and that's with 2 base gaskets that i made myself out of thick gasket paper and no porting i was thinking about getting on a puch high comp head since the batavus head has no squish band so the head is basically useless but then it would cool not as good because of the direction of the fins on the puch head so i was then thinking a pug head has the same bolt spacing and fin pattern so i may get a high comp pug head (50cc) since its same bore almost and same bolt spacing so yah there's another "secret" i have

Re: batavus third transfer?

i was thinking along the lines of the

pug 103 high comp Malossi head

Re: batavus third transfer?

shit talkin' hippy /

was the spacing of your piston at TDC the same as that in my picture? mine is only on there with a paper thin gasket and light sealer. I can't imagine that getting 180 psi. although I haven't tried it yet, so I wouldn't really know. haha

I was thinking of milling the cylinder so the dome of the piston crests a bit out of the jug and then using a tomos head since it has a small squish band and has fins aligned for angled placement

Re: batavus third transfer?

Yes my piston is recessed as much as yours probably a little more so

If you do deciede you want to mill the cylinder i strongly recommend you fit a tomos head on first and then see how much play you have with playdo or something because my piston was hitting my spark plug so i had to add another spark plug spacer thing unless you plan on grinding down the piston or using some sort of weird spark plug that i dont know about lol

Re: batavus third transfer?

oh, that's also with running a head gasket

Re: batavus third transfer?

lose the head gasket, mill the head 1.5mm I've heard you can also mill 1.5mm off the base. Bats are so intentionally slow it's infuriating at times.

Re: batavus third transfer?

🇮🇹💦 Of the Loin /

i have a puch "lo torque" head on that i milled down almost to the fins, with worn out rings (seriously the piston is scarred from bouncing around) im getting about 100-120 psi.

it heats up like a motherfer tho, use at least a b7hs. Im interested to see a picture of this third transfer port tho :O

Re: batavus third transfer?

do it! will totally work

Re: batavus third transfer?

Weird, I've never seen a moped piston that didn't come nearly flush with the top of the cylinder.

Re: batavus third transfer?

shit talkin' hippy /

Grey, I know, it's crazy right?

but If people are getting 120psi and the piston is still that low than if I mill the cylinder to make it normal(with piston near the end of the jug), will it be like way way too much compression?

remedies for over compression? (in case I go too far)

-I could just put on some of those way thick puch gaskets

Re: batavus third transfer?

shit talkin' hippy /

so I'll try it

Re: batavus third transfer?

shit talkin' hippy /

oh jack, and they do make flat plugs that arc off of the sides, but I hear they foul out pretty bad unless you use awesome extremely low resdue uil and perfectly heat matched... buy yeah, that could be a good way to go about completely milling the thing

Re: batavus third transfer?

sounds like a cool looking plug, yah i dont know how you al are getting that low compression, stock my other bat got like 120 psi 600 miles on odometer

Re: batavus third transfer?

dude, put in an extra spark plug washer on your plug so it wont hit the piston. works great. mill the head to the fins and shave down that cylinder.

Re: batavus third transfer?

Maitland, loose, worn out rings do not dissipate heat as well to the cylinder walls, and can cause overheating. Getting rings and a piston that fit correctly will solve the overheating.

Re: batavus third transfer?

I don't really know yet if this has helped me or not since my Bat is a piece of shit and refuses to run for very long.

When it did start it bogged down like crazy from stopped till about 5 mph, then it picked up. I'm on the fence right now if I'm going to give up or keep going with it. Carbide bit though and some patience and you too could have a cylinder as ugly as mine!

Re: batavus third transfer?

shit talkin' hippy /

ummm... that runs?

Re: batavus third transfer?

Sure, but not very well. I know it looks crazy but it really isn't. The piston continually covers the transfer walls that I took out. I didn't touch too much of the transfer windows that open up when the piston is at BDC. And my rings have yet to snag. So yeah, it sort of runs. I think I have carb issues though too. Fuck Batavus.

Re: batavus third transfer?

huh- that would be one way to use a cylinder with a cracked sleeve I have sitting around.

Re: batavus third transfer?

if you wanna get rid of that cylinder ever id appreciate it if you sold it to me for shipping cost, thanks

Re: batavus third transfer?

shit talkin' hippy /

it's probobly running "not well" because you added like 10-15cc to you primary compression ratio right? and I'm not trying to knock on your handy work but the porting does look a bit jagged so turbulance is probobly a factor aswell... but thats awesome ethat that runs! it gives me some hope! thanks dude

Re: batavus third transfer?

🇮🇹💦 Of the Loin /

yeah dude are you still running encarwi on batavus?

vespa dellortos fit on no issue, i just slapped a 12/12 on there (yeah i know intake is 8, but whatever)

Re: batavus third transfer?

Yeah, Hippy. It was more of an experiment. I really have no idea what I am doing. Keep posting, maybe it will inspire me to keep my purple piece of shit!

Hummm, I have a 15:15 but I don't want to deal with making the intake. Thanks Matey!

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