After finding SO many problems with the top end, I had to decide whether to just rebuild the top end, or strip it down and examine the bottom end too. It was a good job that I did as there were problems here too...
The machining to fit a collar in the casing is a very specialised job, which fortunately I have good friends who can do it. Otherwise I'd be tempted to try bearing sealant or something to hold the bearing in place, but I'm not convinced that would work
Such a shame to happen a beautiful bike but it can be fixed. Bearing manufactures make repair sleeves about 11 thou thick for jobs like this on the crankcase, you still may have to get a few thou bored out of the casing to let the sleeve in. SKF calls their repair sleeve Speedie Sleeve, might be worth looking into. I did a similar repair to a B33 crankcase half a few years ago, I bored a few thou out of it on the vertical mill and used a steel WD 40 can as my sleeve as I didn't have any shim steel to hand, did a lot of calculation's mind you but it went together and almost 1500 miles later its still holding.
Fortunately, a talented machinist, and Ariel fanatic friend has stepped up and bored the case, then fitted a bronze insert. So pleased at that. Unfortunately though, loads of issues found with the crank - so many problems found! Will report all on my next video - Part 4!
Best to avoid Locktite in a situation like that. As much as I like the stuff, using it to hold a bearing is not a good idea when in aluminium cases that expand with heat. Be very careful if using Loctite if you heat the case before installing a bearing, Locktite can set up very quickly when heat is applied. As in quickly enough to go off when the bearing is only halfway home. You can sleeve the bore if there is enough meat there, or clean it up just enough with a boring bar and have the outer race of your new bearing chrome plated to build up the diameter. Assuming you can find someone with the experience to do it. You could copper plate it yourself, but chrome is better.
One option…not a great one, but an option all the same.. you can use a Speedy-Sleeve on the OD of the bearing. The sleeves have walls that are 0.011” thick, so increase in diameter of 0.022” maybe too much. Tha sleeves aren’t meant for this purpose, but they do work providing you’re left with enough material to support everything. You will be tightening everything up, so will probably need C3 bearings. Good luck, it’s a PITA. @@t20racerman
Good job you stripped it down. Looks like someone neglected to correct the end float. Loctite 660 is excellent, may save you having the crankcase bored and sleeved. Depends how bad you judge it to be. Best wishes, Dean.
I appreciate modern sealants are good, and might work, but the bearing fit is really loose and if I can get a mechanical solution, I'll do that. If not, thanks for the loctite tip
@@t20racerman you're welcome. As I said, it's a judgement call. If it is a piece of equipment with say, 600 hours to next overhaul and costs a hundred thousand to take out of service, I specify the adhesive solution. The fact that you have it apart already makes a huge difference. Looking forward to seeing the rebuild. Best wishes, Dean.
Hi Adrian. It might be a good time to clean the sludge trap in the crank. (I have a vested interest in suggesting this). I have a VH500 and I have so far failed to undo the sludge trap bolt through the “sump” plate. I concluded that I’d try again if I strip it down. All the best, Bill
A great suggestion, although I did manage to get mine undone last year. Pig of a job as it was so tight. I bought a special, long, 6 sided socket to fit it and that did the job. If I can find the link I'll post it here
Very good. I've been following this, and it's rather like the BSA Bantam I'm still working on. Bought it as a 'restored', and yes looks all OK on the outside, but so many problems underneath! 😲
That's a shame Adrian.. However it does prove that old British singles can keep chugging on with levels of damage and/or wear that would have killed most other bikes stone dead long ago !.. It looks like there should be some shims on the crank pin (or pins) that SHOULD be keeping the crank central with the bore and in the crankcases as well as setting the end float, but those shims aren't doing their job due to not being there !.. At least once you've solved the problems and have got the engine rebuilt, the front brake sorted and the gearbox fettled you'll know that the old girl should be a reliable, solid performer for some time to come.. I don't buy a lot of bikes and tend to hang onto them once I've bought them, but when I do buy a new bike (well, new to me anyway..) I always wonder what's lurking within, even if it seems to be as sweet as a nut.. So for me at least, there's a lot to be said for having that kind of peace of mind !..
Very true - they do tend to keep going! I keep bikes for a long time too - owned my BSA A10 for 40 years, my T20 for 43! The crank did have spacer washers on both sides, but I'll need to check the end float and crank centralisation carefully when I reassemble it.
The main bearing has spun in the casing, wearing the casing and causing the crank to rub on the side of the casing. The casing needs welding and machining back to its original size I'm afraid. You can't build the engine until that is done and I'd replace both main bearings after seeing the damage to the one half.
Agreed. The bearing was very loose, with clear evidence of it spinning in the casing. I'm probably going to get the casing bored, and an insert made to bring it back to tolerance. I will definitely replace the main bearings too.
At least the fix is a simple one. Did you pull the crankshaft in and out to check the end float before you split the halves. When you rebuild the bottom end take extra care to get the con rod as central as possible in the cases.
I didn't check the end float, but will ensure that it's correct when I reassemble it. Ditto with centralising the rod. I'm fortunate in having some talented Ariel expert friends who'll assist me 😊
There are some shim packs available at the moment to help you shim it to perfection. The wear on the inside case on the timing side is worrying because the crank should normally be held against the drive side by the cush spring. I'm looking forward to the next episode. @@t20racerman
