porting picts and success and failures

its raining in so cal, so id like to view ported cylinders to cheer myself up, 10x bonus points for stock slow cylinders. ill start. its a pug 103 w a bunch of extra crap carved in, rips but have a high rpm stutter.

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rusted on og two coil.

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Re: porting picts and success and failures

no that one dont rip, damn picts too small, this one. cant find it double damn.

Re: porting picts and success and failures

Posted these the other day

MST performance adding in the third transfer on a puch e50 engine with a Athena ajh cylinder

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Re: porting picts and success and failures

Thanks for posting this. I literally have no experience with porting, but I'm starting to experiment. It will be good to get some ideas. This should be a very informative and educational thread.

Re: porting picts and success and failures

> Seth B Wrote:

> -------------------------------------------------------

> Thanks for posting this. I literally have no experience with porting,

> but I'm starting to experiment. It will be good to get some ideas. This

> should be a very informative and educational thread.

Here is some more I found from MST performance of the same ajh

Adding that third transfer I’d be worried about the cylinder lining and that thin bridge it creates and the thin piston skirts possibly cracking

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Re: porting picts and success and failures

Yea that skirt is gonna blow. I would do this to a 50cc ajh though, now that is a really fun cylinder that stays really cool.

Re: porting picts and success and failures

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Re: porting picts and success and failures

> Adam Smith Wrote:

> -------------------------------------------------------

> Posted these the other day

>

> MST performance adding in the third transfer on a puch e50 engine with a

> Athena ajh cylinder

Nice work, those transfers look very clean.

Re: porting picts and success and failures

Alan Jackson /

well the op title says success and failures so here's a failure

not on a moped but a 64mm bore

auxiliary exhaust ports that went within a whisker of the stud holes

long time ago and since then ive learned how to get a smooth finish

instead of the "beaver porting" my pals nicknamed it.

it revved to high heaven but coughed and misfired at 7k

wouldn't pull through so you had to keep it 7k and above.

horrible to ride.

aux ex1.jpg

Re: porting picts and success and failures

Did you know that aux port bikes cough like that if theyre too rich? I've see that every time I start my 50cc hobbit before it warms up.

I've done lots of aux ex port cutting and they love lean needles. The scavenging is so good and they pull charge so hard that if you use a standard needle it'll often be mega rich.

That being said, your main ex looks way too big, very snaggable

Re: porting picts and success and failures

Alan Jackson /

the picture actually lies, not as wide as it looked

I did the old 60% of the bore width and used the dunno what its called shape - loaf of bread? so that most of the ex port area was above the transfers

the sides were divergent easing the rings gently out and back in

vertical sides as you know just allow it to plop out and in = snagsville.

and oval ex ports most of the area blow transfer opening calls for a good bit of pipe assist

then I just went wider and wider until I hit 70% with no problems

I was just playing. I tried flat roofed transfers = no difference then to get them angled again I had to raise them and matched the exhaust height so it revved too high for the big heavy old crank

it was just fun -learning by mistakes

11400rpm

same road different/(better) pipe and porting only revved to 8-9 ish (analogue tacho no worky)

in the end I got it going 120mph and 100 sat upright and could play and embarrass the litre hypersports guys on the right road thanks to an enthusiastic riding style that belies my old codgerism

aplologies for bragging

i am in awe of you guys and your achievements with so little to work with and i am now inspired to have a go

just need one more beer......

Re: porting picts and success and failures

That's a great sounding bike

Re: porting picts and success and failures

Alan Jackson /

hopefully the puch will sound better . . . .

Re: porting picts and success and failures

I need to get in the Aux port game!

That bike sounds great!

Re: porting picts and success and failures

Chöschi21 C.K. /

Ths piston came out of a Stock Supermaxi 30kmh(18,6...MPH) with the Stock 10mm Bing and a Biturbo Exhaust a Friend bought, i rode it and know how fast it was with this Piston, as i said, no Mods except the Biturbo and that Piston:

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Re: porting picts and success and failures

Chöschi21 C.K. /
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Now lets start the Guessing, he had this Bike and rode it to school for about 6 Months like that.

My Question is, what did this Bike run on level Ground with the Exhaust port opening about 3mm at TDC? What do you think?

Re: porting picts and success and failures

That choppy shit on top was just a very overdone version of ring land porting.

Are you saying that window was on the ex side? Pretty stupid if so.

Re: porting picts and success and failures

Chöschi21 C.K. /

The Skirt was shortened about 7mm and there is a Piece Missing on the Intake side, the Exhaustside has a Window and the Holes for the Boostports are in the Normal position on the Intake side, just both are connected.

Re: porting picts and success and failures

There is zero reason to window the exhaust. Just blowing out mix.

Very foolish

Re: porting picts and success and failures

There are no boost ports in that cyl.

Re: porting picts and success and failures

Chöschi21 C.K. /

There is a Boostport, have you ever seen a Supermaxi Cylinder?

Just to clarify, i dont know who modified that piston, i haven't done it, it came with the Bike. (edited)

Re: porting picts and success and failures

Oh so the window faces the intake not the ex to feed those boosts.

Re: porting picts and success and failures

Chöschi21 C.K. /

Ah, i think we are talking around each other:

This is the Intake side, the Window rounded with Red is the Window for the stock Boost Port, The Green Circles show how it would have looked stock and not connected:

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And this is the Exhaust side of the Piston, as i said, the Piston skirt is already shortened 7mm compared to a Stock Piston, and that window is at least 7mm High:

Unbenannt11111111.png

Where we come from we call both of those "Kolbenfenster" wich means "Piston Window" and we normaly do the second style on the Intake side if we don't want to port our cylinders. Mostly because it's easier to go back to stock if you only have a modded piston and don't need to find a Stock cylinder again.

Re: porting picts and success and failures

Ya I just didn't know supermaxi had the piston port boosts over the intake. Makes sense now

Re: porting picts and success and failures

Chöschi21 C.K. /

Question is still Up, how fast did it go? Stock E50 Supermaxi with that Piston and a Biturbo,Stock 10mm Carb and Stock 13:47 Gearing!

Re: porting picts and success and failures

It doesn't matter how fast it went

Re: porting picts and success and failures

Chöschi21 C.K. /

well, i would say it does, because even if it didn't have any Power, it hit 55, (34mph), it reved to high heaven, nearly 10'000 RPM, with a 10mm Carb and an Exhaust diameter of 19mm.

Re: porting picts and success and failures

34mph is nothing to boast about frankly.. My 40cc goped does 34mph. I ride my bicycle at 34mph.

I eat babies at 34mph

Re: porting picts and success and failures

Chöschi21 C.K. /

Shure about that? obviously you could get a lot out of that Cylinder, even unported, but it's still quite a lot for what it was.

Re: porting picts and success and failures

please stick to mopeds please.

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