Pocketbike Forum banner

1 - 15 of 15 Posts

·
2 Stroke Specialist
Joined
·
330 Posts
Discussion Starter #1
this is a test of the effectiveness of boyesen ports in a cylinder reeded gp460 engine. the theory is that the intake port linking to the crankcase bowls acts as a booster port aiding extra fresh air/fuel during the upstroke while the transfers are still open filling the combustion chamber, i believe in 360 degree intake port timing, and that the engine will always be free to pull in more fuel at any time, especially when in high RPMs when power/torque usually starts arching off.


this is my current 3rd 460 build going on a special GSR40 "race" frame thats been Y-ed in the rear, the two reeded GSR46Rs are my evil twins ones a 5th port, other is a 6 port, the boyesen motor is a 6 port, but if i like what i feel on this, ill be going back and boyesen porting the original 2 460s. ive done this style or porting to G260RCs literally 10 years ago to the month and that was the most insaine little RC style motor ive ever built, rode, or seen ever in all my years,... so if the first test 10 years ago proved amazing results, my expectations are pretty high on this one.


 

·
2 Stroke Specialist
Joined
·
330 Posts
Discussion Starter #5
take note of the main transfer roof angles ;) to all the copycat porters dont try this at home, drunk in your garage ;)

 

·
2 Stroke Specialist
Joined
·
330 Posts
Discussion Starter #9
ill sell this motor complete as im looking to build a 3rd polini motor for my micro kart, PM me if interested.

list of mods:
GP460RS engine
super clutch with modified springs
full reed/race porting with one off boyesen porting
japan NSK 8 ball case berings
balanced flywheel
trued and balanced crank
modified TS 460 cylinder reed
ada steel exhaust manifold match and flow ported
hda48 carb with modified pop off
crankcase clutch venting and crankcase bearing lube ports
 

·
MidnightMidbikeSyndicate
Joined
·
888 Posts
hey KevinT. I am super curious about the tire track cuts in the crankcase. Whats the idea behind that??
as am I... please explain
 

·
Banned
Joined
·
21,721 Posts
Its the same idea behind turbo cutting a r/c car crank to help draw and scatter fuel into the topend faster aswell as keep the atomized mix atomized...Thats the job for extra velocity thru blueprinting and crank stuffers/reed stuffers and the rotating rod of the crank so theres no need to turbo cut the crank counterweights or grind the case..

Theres been members who have tried it to 2 stroke engines[me and 2strokeblowinsmoke] and have found it doesnt make an increase in perf ;-only an increase to crankcase volume.........Turbo cutting of the crank only works on turbo ported nitro glow engines that spin over 42,000rpm's.



 

·
MidnightMidbikeSyndicate
Joined
·
888 Posts
Thanks cam I get it now.
 
1 - 15 of 15 Posts
Top