Buying 49 mm iron sleeve kit need help

Jayraye39

Member
Joined
Jul 13, 2021
Messages
83
My current cylinder keeps getting scratched by the piston rings I'm fed up with it I think I'm going to go ahead and pull the trigger on a 49 mm iron sleeve kit for 50 bucks a couple questions where is a good place to buy this kit that's in decent shape and not crusty ports. Also if upgrading to a bigger cylinder and piston do I have to modify my head or will the squish band still be the same
 

Street Ryderz

Well-Known Member
Joined
Oct 14, 2016
Messages
4,326
My current cylinder keeps getting scratched by the piston rings I'm fed up with it I think I'm going to go ahead and pull the trigger on a 49 mm iron sleeve kit for 50 bucks a couple questions where is a good place to buy this kit that's in decent shape and not crusty ports. Also if upgrading to a bigger cylinder and piston do I have to modify my head or will the squish band still be the same
All the iron sleeved cylinders I've seen have small port area's that need correcting along with the timing changes if doing so, the head has to be re machined to bring the squish band out to the 49mm dia so 1mm wider all around with the same angle.
Clearances and rig gaps with the Chinese parts is a gamble at best, if you want to build a better performing longer lasting engine there are better options and things you can do to achieve this, Like ceramic coated cylinders (same process as nikasil) Mz has some g4 versions or Falcon 911 has a dio reed or piston port version's and these with a properly fitted piston and and a single ring or two 1mm thick ones instead of 2 2mm thick junk rings make a huge difference in wearing/braking in properly and then sealing better for longer life and better performance. Do your research there is alot of info on the site about the steel/iron sleeved jugs, Ill give you a heads up they are not done right by any means shape or form, most crucial to me is the bores are not straight when checked with micrometer along with being ill fitted and needing alot of work not worth the effort to me.
 

Jayraye39

Member
Joined
Jul 13, 2021
Messages
83
All the iron sleeved cylinders I've seen have small port area's that need correcting along with the timing changes if doing so, the head has to be re machined to bring the squish band out to the 49mm dia so 1mm wider all around with the same angle.
Clearances and rig gaps with the Chinese parts is a gamble at best, if you want to build a better performing longer lasting engine there are better options and things you can do to achieve this, Like ceramic coated cylinders (same process as nikasil) Mz has some g4 versions or Falcon 911 has a dio reed or piston port version's and these with a properly fitted piston and and a single ring or two 1mm thick ones instead of 2 2mm thick junk rings make a huge difference in wearing/braking in properly and then sealing better for longer life and better performance. Do your research there is alot of info on the site about the steel/iron sleeved jugs, Ill give you a heads up they are not done right by any means shape or form, most crucial to me is the bores are not straight when checked with micrometer along with being ill fitted and needing alot of work not worth the effort to me.
Damn sounds like alot of effort. Not to mention I also heard after heated they tend to drop. So would have to pin it also. Thanks for the heads up maybe I'll just stick with the 49 cc chromed cylinder. At 30 or so dollars they can easily be replaced. Thank man
 

Karl Snarl

Well-Known Member
Joined
Sep 20, 2019
Messages
3,319
Theres a guy on ebay that will port them to your specs for 125. You order and comment what you want. He ports and sends the cylinder to you. Hes not bad. I have all the tools so im good. I'll get the link later. Im on my phone and dont know how to link. Hes from Chicago. Buddy pulled the trigger and yeah hes not bad. Cylinder delivered the power band or there abouts he claimed with the porting.
 
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