hybrid chinese motors and performance tuning

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foureasy

New Member
Jul 9, 2009
478
0
0
tucson
about 2 months ago i picked up 3 stock puch heads for less than 20 bucks, they up the compression on the ht motors and add a lot of cooling here in tucson, where its 71 deg right now
 

furament

New Member
May 31, 2009
213
0
0
ontaro
dude ill just listen you go fast i dont and ya i got old to soon:( have you aney thoughts on a liqwed cooled set up? 400$ isent to far of for this project and i can build parts but i live in a macinest dead zone so im on my owen
 

Riding Rich

New Member
Aug 14, 2009
349
0
0
pa
Hey Foureasy

Is that still a 47 mm bore.
What bottom end did you use.
Did you throw the crank?

Just curious.
 

furament

New Member
May 31, 2009
213
0
0
ontaro
foreasy is the gurue if we talk to much **** kill us maby we can go fast if and only if he tells us k:) but we have runed this thred!
 

BarelyAWake

New Member
Jul 21, 2009
7,194
21
0
Maine
o_O

I can't for the life of me figure out where there mighta been some "offense" taken or given... I could be wrong - but I think it was jus' a case of "hard to tell tone w/text" again lol

heh - in many ways, a forum is teamwork by it's very nature ;)
 

foureasy

New Member
Jul 9, 2009
478
0
0
tucson
i just don't see the point of your spreadsheet, no one calculates time/area figures, because it doesn't work on every engine. it's much more effective to change timing a few degrees with the piston shape then continue making the same small changes with the ports until you go too far, then it's a simple matter of a new piston to get you right in the sweet spot.
if you want to do some math, then design a pipe. from my experience though, it will need to be shorter than either of the real guru's tell you.
 

foureasy

New Member
Jul 9, 2009
478
0
0
tucson
soooo foreasy did you use the 80cc base for your beast do you think a 49cc bace could work?
i used the 80. i dont know what the stroke of the 49 is. these cylinders were designed for a 43mm stroke, our stroke is 40mm. either way you will have to make a base plate to raise the cylinder.

right now i am in the process of re balancing my crank. after about 5-6000 rpms the motor starts vibrating bad enough to break exhaust pipe. so i tore my motor apart yesterday and milled as much material as was removed from the factory (in addition to what was removed from the factory) from the same spot on the crank balance pads. hopefully that will put my sweet spot at 10k.
 

foureasy

New Member
Jul 9, 2009
478
0
0
tucson
heres what i removed from the balance pads. i wil fill the entire thing with silicone to up my crankcase compression.



this happened the other night after blasting past a car on 4th ave and failing to notice the trolley tracks. thats what i get for laughing at everyone else who has wrecked the same way.



box o parts



after i went down and the intake broke off, the motor stuck at full throttle while laying on it's side with a giant air leak. i think some street got in there and bounced around. everything looks like it'll be ok



can you see the tiny mark below the transfer? that is the only cylinder damage. i love nikasil
 
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Riding Rich

New Member
Aug 14, 2009
349
0
0
pa
I recognize that rod.
It is out of a GT-5 66cc Angle Fire.
I believe the center to center distance is 88.9 mm.

I have one question if you can please help.

How much pressure is required to push the crankpin out.
Or if you have the crankpin diameter and the bore diameter in the crank i can calculate it.
 

skipu

Member
Aug 6, 2008
184
0
16
New jersey
I recognize that rod.
It is out of a GT-5 66cc Angle Fire.
I believe the center to center distance is 88.9 mm.

I have one question if you can please help.

How much pressure is required to push the crankpin out.
Or if you have the crankpin diameter and the bore diameter in the crank i can calculate it.
just push it out bro !!! you really love #'s dont ya just saying i build race car motors and bushed rods pin pistons and sleeved cylinders pressed cranks in dirt bike motors never have i measured the amount of pressure it takes to get them out only size them so they go back together properly just saying you may make foureasy crazy with asking for mad #'s on this thread you have a extensive knowledge of building motors it seems from other posts if you never split a crank give it a shot it is very simple and i like your porting thread ive done this before now = i just wing it from all my past experience ive done everything to these motors only to accomplish 5 to 5.2 hp on a speed to wieght calculator my bikes only go exactly 40 with a 36 t but pull like mad from bottom to top take it easy bro and keep up the good work on the porting thread gotta go goin street racing in the big block stang hope i can hook up !!!!!!!!! COLD HERE BRRRRRRRRRRRRRR!!!
 

skipu

Member
Aug 6, 2008
184
0
16
New jersey
heres what i removed from the balance pads. i wil fill the entire thing with silicone to up my crankcase compression.



this happened the other night after blasting past a car on 4th ave and failing to notice the trolley tracks. thats what i get for laughing at everyone else who has wrecked the same way.



box o parts





i love the pop up piston gives you alot to work with looks like ill see when i get my parts good thread and thanks again i think this will be the next level in performance due to the stock cylinders being so limiting thanks again me and my brother wanted to make our own cylinder this is truly a better option i love it !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.shft.