Everything2Stroke - How Its Done: CR500 Liner replacement
  • How Its Done: CR500 Liner replacement

    My next project is from Louis. 3 CR500 cylinders, 1 for a bore, 2 new liner + decomp & 3 who knows?
    My first challenge is liner replacement + fixing the Decompression mounting. This cylinder has had multiple chrome plating jobs. Chrome has a habit of a good chemical bond with the iron liner. This stuff really sticks and is equally difficult to remove. Another problem for you rebuilders with only a cylinder boring machine, chrome plating removal from an iron liner can seriously damage a Quik Way machine. Itís too damn tuff to remove with a machine which was manufactured to do very precise machine work.
    My only Quik Way machine is a lightweight FWS which is only designed to bore up to 3-3/4Ē, kind of a stretch for the 500cc group. I decided to set this cylinder up in the lathe so I can take extra heavy cuts to get under the chrome as quickly as I can.

    My first step on a special project is to machine a parallel plate to fit the cylinder, usually from the bottom. This set up has two useful purposes. The first is so I can clamp the cylinder to the boring stand with 3 or 4 C clamps instead of pressing it from below. Itís sometimes difficult to clamp a single cylinder to the boring stand perfectly parallel. Second and most important, I have full clearance from the bottom to check the bore diameter with my dial bore gauge. Thereís nothing to get in the way.

    You can plainly see the layers of chrome in the top end of this cylinder.

    Back to the lathe: I have a blank cylinder casting mounted up in order to check the run out accuracy of the 3-jaw chuck.

    A 3-jaw is OK to grab a single cylinder provided that itís accurate enough.

    The next thing which is needed is a large live pipe center to align the tailstock end of the cylinder.

    After everything is aligned and tightly clamped we can start cutting out the guts of the cylinder.

    This cylinder is one of the nastiest that Iíve ever cut on. When removing the chrome, deep cuts must be taken to immediately get under the chrome. After around 1/8Ēor 3mm has been removed, the bottom feet fall off the cylinder.
    This is where replacement sleeve manufacturers vary in their liner sizes. Most make the sleeves thin enough so the bottom end is easy to deal with. I preferred to remove everything & weld the base. In my opinion and experience this is the best way to make this repair. The majority of Japanese manufacturers use this design to hold the iron cylinder liners in place.

    In the intake area the piston could use some extra support. We will install more ribs, vertical & horizontal. I have a very conservative attitude when cutting new ports. Some customers disagree with me. Personalities may clash on occasion. (You can always remove material but you canít put it back on)

    We can see where the decomp equipment is engaged in the cylinder. After the new liner is installed there will be only a ľĒ hole. I donít like to criticize others, this decomp installation is difficult. The aluminum cylinder casting is so thin that it isnít possible to screw this installation together tightly. Next time you will see how this installation is changed by welding everything into place.

    At this point you can see were the welding needs to be done. It appears that the 2 exhaust ports could be ďButter fliedĒ or winged as you guys say. How about an opinion from you porting wizards?

    One more photo. The cylinder was cleaned with the Bead Blaster prior to welding

    This photo shows the base surface after welding and re decking. There are a couple of small buggers in the welds. Any of you who have welded cylinders which are penetrated with oil will relate to this.

    Next week Iím finishing up a new set of chuck jaws with long fingers so I can rechuck the cylinder from the other end. Lou will need to decide if anything else needs to be done before I continue.

    This is kind of a community project. Please chime in with your comments and ideas, Good or Bad. We are all in education mode with this read. Iíll bet that Lou is open to any constructive ideas.
    Later, after 4 hours at my keyboard my fingers are getting sore. Wash your Hands
    ďOld DogĒ
    This article was originally published in forum thread: How It's Done - Projects around the Shop started by John Tice View original post
    Comments 4 Comments
    1. cablecrewracing's Avatar
      cablecrewracing -
      hey John, is the decomp assembly actually in the cylinder wall? That is how I understood what you wrote, but I have only seen them put into the heads. I might just have to send you my freshly worked cylinder along with the case that needs repaired so you can install one in it.
    1. John Tice's Avatar
      John Tice -
      Hi cablebros: The compression release which I installed in one of Lou’s cylinders was done when we installed the new liner. The hole on the inside of the new standard bore is ľ”. This is a special job which can only be done with a new sleeve installation. I’ve not heard from Louis & figure, no news is good news.
      I’d be happy to work on your broken case, please send some pictures.
    1. flotek's Avatar
      flotek -
      That's a lot of work no doubt .often its cheaper and makes more sense to buy another used cylinder on eBay than sending it to be resleeved . A good cr500 jug can be bought for 200-250$
    1. OConnor Racing's Avatar
      OConnor Racing -
      I have a Quik way and Van Norman CB and run into the same problems removing thick plating. I'm not going to beat the hell out of my machines. I send them to Powerseal USA and they chemically strip them for $25. I just pack them with the cylinders that are already going out for plating to save the freight. LA sleeve makes what I call an upside down sleeve for the CR500. The flange of the sleeve is at the bottom, not the top. You need to counter bore the cylinder at the bottom where the transfer ports are and proceed as usual. I've done a bunch of them and no complaints. It will save you some welding time.
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