hi steve and welcome to the site. dax is a member and i will let him answer the question on the speed for i am not sure. i know people are getting in the high 30's but not sure about the 40's which is pretty fast on a motorized bicycle. i also ordered a titan and looking forward to recieving it.
i have not tried the clam shell and heard they are a real bear to work with so i opted to getting a rear wheel with disk brake mounts to mount the rear sprocket to.
the 4 stroke bicycle motors do not have a white wire on them.
dax will take good care of you. i had lots of questions prior to ordering my dax 4 stroke bicycle motor and he was awesome at answering my questions ect before i ordered. can't wait to here about your build. i am moving to the virgin islands sunday and will post my build and we can share ideas. here is the mountain bike i will be putting the motor on
my mountain bike soon to be motorized