Best 48CC recommendation for my next Cruiser build?

[Greg58]

I have run 48’s since 2011, my best is a grubee GT2B. I haven’t found a engine yet of better quality. The fit and finish, port mapping and has a squish band on the head. I have bought many heads from several vendors trying to find a replacement head to use on another 48 that has the squish band with no luck. I ordered two from the above mentioned CHD and theirs doesn’t have the band either.

 

[Greg58]

If you deck the cylinder, shave the head and add a good expansion chamber with a tuned carb you can reach 32-33, that’s about all a 48 will do. I hit 32.9 on my 24” tire bike at about 7900 rpm.

 

[Greg58]

Both of my 48’s run about the same, I have found that they perform better with lower gearing, I run a 44 on 26” wheels and a 40-41T on 24” wheels. If you have a shift kit you can probably do better.

 

[Greg58]

The engine on my avatar is a 48 from BGF on eBay, stock it was no where near the grubee. After porting, trimming the piston skirt, decking the cylinder, ramping the piston to improve port timing along with shaving the head it is about equal. A no name entry level engine can be made to run good.

 

[Mossy]

I have run 48’s since 2011, my best is a grubee GT2B. I haven’t found a engine yet of better quality. The fit and finish, port mapping and has a squish band on the head. I have bought many heads from several vendors trying to find a replacement head to use on another 48 that has the squish band with no luck. I ordered two from the above mentioned CHD and theirs doesn’t have the band either.

I have a 2012 gt5 and the grubee steel sleeve super rat with BFG rat bottom... Grubee is top notch just need to balance it

 

[Greg58]

The GT2B is balanced well, I’ve turned mine to 7900 rpm. I haven’t balanced that crankshaft, I have a gt5 type 38mm stroke that I balanced that turns high enough rpm’s for me without vibration.