49mm steel sleeve motor

[Mossy]

Has anyone have any experience or sudgestions

 

[Greg58]

I've got a 40mm stroke that I converted to 49mm, I bought the piston, cylinder and rings from ebay. I also have another one I plan on using on a 38mm stroke that uses the high pin piston.

 

[Greg58]

I used a stock head on mine, it has plenty of power for my riding, yours should run cooler with the tall fins. I would like to know the port timing on yours, I think I've got my exhaust a little higher than it should be, low end torque is not what I think it should be.

 

[Mossy]

I used a stock head on mine, it has plenty of power for my riding, yours should run cooler with the tall fins. I would like to know the port timing on yours, I think I've got my exhaust a little higher than it should be, low end torque is not what I think it should be.

I don't have a degree wheel as of yet to measure duration etc... I'll post what I find when I get those things together...

 

[Greg58]

I downloaded one and adjusted the print size till it fit perfectly on a DVD, then I used spray adhesive to attach it. I have a 8mm bolt with a piece of hose that I slide on the crank with the nut off. It’s accurate, I turned it three complete revolutions and it zeros out.

 

[Greg58]

I use a alligator clip gripping a fin on the cylinder as a pointer.

 

[Mossy]

I downloaded one and adjusted the print size till it fit perfectly on a DVD, then I used spray adhesive to attach it. I have a 8mm bolt with a piece of hose that I slide on the crank with the nut off. It’s accurate, I turned it three complete revolutions and it zeros out. View attachment 110752

I really like that

 

[Mossy]

I don't want to change the ports much just match the sleeve to the ports and shape the transfers but it's going to be a few months before I get set up with a space to work on things I'm just collecting parts while I'm remodeling my place

 

[Greg58]

I built our house, then remodeled, now I’ve made it more accessible for retirement. You never finish you just change direction.

 

[Mossy]

I'm going to try something different... Instead of diving in to the porting I'm going to wait and degree the cylinder then rough up the ports and transfers for devcon the original JB weld to bite to ...then do the ports and give the transfer a nice sweeping angle to push the charge away from the exaust port... It will take more time to get right and I have the time... I also have a bunch of ideas for pipes and expansion chambers to mess with... I've been collecting parts for almost a year and have a bit of everything out there... The 49mm only has one piston available for low hole 38mm (37.5) stroke so I'm thinking the 40mm crank would need a thicker base gasket to compensate... Or it might just be perfect with a dome shaped head ? I just don't know what I actually have until I get building and am studying up on the various forums to get an idea how to work around the motors inconsistenty... I think a lot of it depends on the batch of parts made... My 2022 motors may or not be the same as someone else's 2021 edition or so on... I did get a batch of window pistons with the windows cut out of the exaust side and returned them... So eventually I will figure it out and the forum has helped with that...