Transfer Port Modification- Pictures and results here.

[bairdco]

the thing you gotta watch out for, is going too big and compromising the strength of the weld. there's not enough metal to match it completely. if you go too far, your pipe's gonna bust off.

i wouldn't worry about the cylinder ports. the last thing you want to do is mess those up. one tiny chunk of metal left in there, and you've got a disaster.

the intake can be matched, too. i think it helps more than the exhaust.

is your motor broken in yet? if not, you might not feel any real benefits out of it. but it can't really hurt.

 

[Tcams]

Yeah ive put like a gallon and a half threw it. Im pretty sure its broken in because ive seen a big improvement on throttle response and ive gained about 3 mph since first tank.

I herd that the exhaust was more important, anyhow im going to port the intake as well
I hope I will see some improvements in something.

 

[Riding Rich]

Tcams Zonie
Yes i would match up the ports and gaskets as perfectly as possable.
Just watch the sealing surfaces and make sure the intake and exhaust pipes will still seal on the motor.
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Dont grind the inside of the ports in the motor or you may wreck it.
Got to know what your doing.
I found out the hard way.

I put 2 base gaskets in with a compressed height of .050 inch total.
Ya know what the motor ran like crap.

Pulled them out last night and ohhh boy shes rockin now.

I also ground off .090 on the piston skirt intake side.
This 48cc runs so strong now i can't even hold it WOT for long.
I like to go fast but not that fast.
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This verifys that the intake port needs to be lower to gain better Duration.
The # of degrees of crankshaft rotation for that port = Duration.
Moving it up must shorten the number of degrees and actually gives the motor less time on the intake cycle.

Moving it down must increase the time it has to pull the charge in.
Therefore giving outstanding performance.
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I'm gonna leave the 48cc Grubee alone now.
It's running soo good i couldn't use any more power anyway.
Will do a port map when i get the motor off the bike and the new motor on.
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I just got my PK80J Limited edition Slant head yesterday.
Motor is rated at 68.5cc.
It has the wide 40+mm front mount for large tubes.
No more drilling!!

Looks like the porting is allready improved.
No blockage of the intake at TDC by the piston skirt.
Different angles and much larger ports.

I'm gonna pull the base gasket before i run it as well as some other things.

It was very interesting to see also that the transfers in the crankcase were cast similar to the way i ground out the Grubee.

One less thing for me to do.

But that further confirms if you grind them steps out like my photos show it's a good thing actually used by Pizhou YongXing Gasoline Engine Factory.

Also this motor has a Dome Shape piston head.
Thats a plus.

Looks like it was built to perform.
Lots of metal particles throughout the entire motor though.
Brand new never started "thankfully"

I't is definatly a good idea to take em apart and clean up things before you run it.
That metal woulda took a lot of life away.

Anyway i'll be doing a large amout of work on this one and will keep you guys posted.

 

[Tcams]

I did some work on the intake manifold this morning.

 

[Riding Rich]

I'd buy 1 of thoose billet intakes.
There awsem.
Just got mine yesterday and it matches the port pretty good.

 

[Tcams]

Hey rich how do you like the billet intake?? Did you have to modify the clutch arm?
Any gain in performance, flow, anything that you noticed.

 

[Riding Rich]

I do like the billet intake.
Yep had to cut some of the thread off the bottom of the clutch stud.
Currently my bottom end is going in my grubee but it still flys.
I like that the Billet intake is tapered outward to match the port.
On the inside where it meets the engine.
Also the o ring on the end is nice.
Seals up alot better and looks better too.
The other benifit for me is with the std intake i couldn't get an air cleaner on.
The billet moves the carb FWD a little.

It is soo cheap i would definatly get one.

 

[misterww225]

reading this post in great interest.

 

[misterww225]

I have modified half a dozen of these chinese motors for my son and his friends. I tried several mods to find combinations that worked well.

 

[Riding Rich]

Port Mapping / Timing Durations

Misterww225

Very Nice post.
I'm gonna use the software so we will see what i come up with.
It will be interesting.

You actually cut out the Cylinder wall to make the transfer ports shorter?
I usually thin out the webbing.
How about some pics.

Anyway i'm gonna break off here and start a porting thread.
This thread is getting pretty long and mixed up.

 

[skipu]

Whoa! Hold on there killer....a normal two stroke engine will have a compression of 9:1 or a little higher, but certainly not 15-17:1 or higher.

Ours are closer to 6:1 which is a little low.

15 : 1 is very common in cy and zenoah motors that i use on my 5th scale race cars and boats and these motors run anywhere 26 cc to 29 cc from 13000 to 16000 rpms can make around 4 hp but the torq would not be there to pull the wieght of bike and rider although these motors really get a goped going oniel bros. racing has a 42 mph goped check them out real good guys down there i raced with them at hostile hobbys bajafest good people

 

[Bikeguy Joe]

You will agree that those engines are the exception, and high performance, no?

 

[skipu]

yes they are very good performance motors and there are not alot of other motors out there with that kind of compression but i always change my compression recently i took a china engine and took .025 off the jug and profiled the head my squish is pretty good very tight feeling now i hope to see how well it works by next week i also resurfaced and blended the transfer ports put a radius on the piston matching the head widened the exhaust port raised it .020 lowered the intake port .020 and matched piston to port and case matched it ive done all these things before with good results so i decided to combine them all aside a couple limiting factors i have 5 pipes i go through back and forth untill i feel i have the cleanest tune then i show these little motors no mercy and see what happens one after the other they are cheap enough way cheaper than my car and boat motors but i love 2 strokes and im tinker addict as are almost every one on this forum i think ive been watching some of the porting threads there are alot of techiques out there

 

[rohmell]

It's been like 8 months since the last post in this thread.
Any new developments with the SuperEngine?

 

[rohmell]

I guess this is just another example of MM vaporware?

 

[Lord Helmet]

I guess this is just another example of MM vaporware?

 

[biknut]

The problem had to be the price. There's no way to make a good motor for $350 in America, and make any profit.

Every china girl crank needs to be taken apart, and put back together, balanced and trued. Just that alone is $100 at least.

If you're going to use a stock cylinder, even after porting, you're not going to gain much, but a $100 more anyway.

New custom cylinder head, I think they were $79. Then there's gaskets, and labor.

Make it about $700, but who wants one now?

 

[Goat Herder]

I fell in love with two strokes.. The H.T. motor birthed it all for me and was a dream come true! Yet last over time lol.

What it took for was to make a leap of faith for better. Proud owner of 4 Morini engines now money well spent. Two Liquid Kewled and Two Air Kewled.What I have put just one my engines through so far... a H.T. simply could not live to tell. Just one motor for me has equaled 4 or 5 China H.T's life spans, no reworking or major hassle's with three times the H.P. power out put and run's absolutely as good as day one.

But hey there is always a cheep H.T. some where out there? Replacement that begs for/needs practically rebuilt and blue printed? Like Dorito's they do make more and make more and more.

I did get one good H.T. motor and I know their out there! but the EPA ''I guess?'' said we had to get some other batch or something lol. after that I spent my money on Italy. Still think it was a good decision in hind sight. Sure was a chunk of change for me at the time. tho That is behind me now!


My buddy here teased me relentlessly about the extra money spent. Thing is after his third H.T. it stopped.....

He teased me about the noise level with my first bike. Later I found a way to make it very pleasantly quiet.. That stopped too.

 

[javy mcdees]

I fell in love with two strokes.. The H.T. motor birthed it all for me and was a dream come true! Yet last over time lol.

What it took for was to make a leap of faith for better. Proud owner of 4 Morini engines now money well spent. Two Liquid Kewled and Two Air Kewled.What I have put just one my engines through so far... a H.T. simply could not live to tell. Just one motor for me has equaled 4 or 5 China H.T's life spans, no reworking or major hassle's with three times the H.P. power out put and run's absolutely as good as day one.

But hey there is always a cheep H.T. some where out there? Replacement that begs for/needs practically rebuilt and blue printed? Like Dorito's they do make more and make more and more.

I did get one good H.T. motor and I know their out there! but the EPA ''I guess?'' said we had to get some other batch or something lol. after that I spent my money on Italy. Still think it was a good decision in hind sight. Sure was a chunk of change for me at the time. tho That is behind me now!


My buddy here teased me relentlessly about the extra money spent. Thing is after his third H.T. it stopped.....

He teased me about the noise level with my first bike. Later I found a way to make it very pleasantly quiet.. That stopped too.

Is that Morini still pushing down the road?