I'm restoring a vintage Triumph motorcycle and discovered that the alloy cylinder block (Wellworthy, I believe) is cracked, near the exhaust ports, through the sleeve and cylinder block.
Replacement sleevers are no longer available from Wellworthy and I would like to make new ones to press in after welding the cylinder block. My question is: where would I find suitable cast iron pipe for making the sleeves? I have access to a lathe and milling machine, as well as welding capability.
The intent is to restore this machine but not as a daily rider. That said, I would rather do the job correctly.
Clevite among others make "tincan" dry sleeves, most any auto machine shop would be a source as would a decent supply house. ie NAPA ect. Welding cracked cast iron engine blocks is somewhat of a black science to my understanding. But some of the new type of rods look promising, I have no experience or connection with
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for example
years ago in another life I witnessed cracked webs on heavy duty diesel blocks successfully welded. They always came back without any warrantee and sometimes were known to crack/leak later.
There's a guy near me that has forgetton more about this sort of work than the rest of us will ever know. I had him do a ford tractor with this exact same problem. He found a cast iron sleeve that he could machine to fit and did the welding on the block.
If you don't mind shipping the block accross country (Minnesota), I'd suggest him. Otherwise, I suggest you find another fellow like him. This sort a repair is not for a novice.
Perhaps, I did not make it clear enough that what I am dealing with is a twin cylinder, cast aluminum block, which has cast iron sleeves pressed in. Once the defective sleeves are pressed out, I'm not attempting to weld anything but the cracks in the aluminum cylinder block, after which new cast iron sleeves will be pressed in, finished to final bore and honed to match the new pistons. These procedures are clearly outlined, in detail, in several books on the subject, namely: "Tuning for Speed" by P.E. Irving and "Modern Motorcycle Mechanics" by J.B. Nicholson, among others, and not beyond my range. There are several vendors who would perform the resleeving for me, but I don't have enough equity in my home for a large enough loan to cover their fees.
My question is more in regard to a source for the materials: cast iron pipe, of the approximate wall thickness/diameter for this type of application. Roughly, say, 2.5" bore and 3.00" outside diameter. It would be preferable to find the type of cast iron with the correct characteristics, as well. Thanks again, Norman C.
I shall follow your suggestions and check with Clevite, for sleeves. It had not occured to me! The weld I would undertake would be in the aluminum cylinder block, after the defective sleeves have been pressed put.
Had a Series 2 Landrover that put a rod through the block in Central Africa in the seventies. We bored out the block to accept a Ferguson
35 (IIRC) sleeve that we modified to shrink/press fit, then rebored the sleave to the proper dimensions to install a standard size land rover replacement piston. Likely took close to 40 hours of work, but a replacement engine was out of the question, and we DID have both a boring bar and a large lathe on-site. We froze the sleave, and heated the block with a big rosebud, then quickly pressed the frozen sleave into the hot block. We let it sit a couple days, then reheated the block and sleave together, and let it cool real slow to stress relieve it, and were fortunate to find the block had not warped.
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Considered going back to stock cast iron cylinders?
Might as well shop for a source for a set of them while you are looking, on the likelyhood that there is a better chance of success when there is a backup plan...
Rode a Norton 850 for a few years, as sole source of transportation, had a couple Triumphs, and currently have a 69 Bonny project waiting quietly to beccome job # 1 for a rebuild.
As others have suggested, save yourself the misery and source out some sleeves from the automotive suppliers. At least that way, you can expect the material to be suitable for the use from the start.
Norman, That sequence is incorrect. Weld first. Bore out to new size. Order sleeve. Press in place after arrival. Simple. Try LA sleeve in the States. If they don't have it, they'll make it for you. Good picing as well. Steve
Steve, OK, I'll review the sequence of events. I surmise the probability of distorting the block is high with the liners removed. It makes sence to me, and thanks for the input. I'll look up LA sleeve tomorrow and see what the've got.
Well, welding cast iron CAN be a problem. I would suggest that the easiest course of action is to seek out a remanufacturer of Diesel Engines who has a lot of experience with the process. "Coincidentally", WE do that sort of thing...and here is a link to the website http://www/dieseldhp.com/ FOr greatest success, one really has to pre-heat the part to be welded, and, the cracks have to be ground out to get rid of ALL surface contamination. Also, while it is possible to stick weld these things, gas welding is a far better process. Not only does one need access to welding equipment, but, of course, the gasket seats and ports will have to be re-milled, so, access to a good, vertical mill is vital.
Yea...that can be a problem, although it has been our experience that often re-cracking is a problem of technique, rather than issues with the process. We do have heads come though the plant that are impossible to weld, as every time we weld them, they crack some OTHER place, no matter how carefully we do it. Often, though, these are older heads. SO far, though, we have a pretty good success rate, upwards of 99%. Most of the warranty issues we run into seem to come from incorrect installation, rather than failures of the welds...but then we do work pretty hard to make sure that any head that is likely to fail never makes it out of the shop. Regards Dave Mundt
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