Author Topic: A65L Crankshaft welded sludge trap access  (Read 338 times)

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Editor

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Re: A65L Crankshaft welded sludge trap access
« Reply #15 on: 03 November, 2017, 18:11:26 »
I would take it to a machine shop - probably a local engine reborer etc. and ask them to set it up on a vertical milling machine and using a 1" plus slot drill, remove as much of the welded area as poss, exposing the original bore to see if the sludge trap is still there or not. I would then get them to sleeve it with a 7/8" cycle thread internal thread sleeve and a larger thread on the o/d. Thoroughly swilled out afterwards it will be as good as new! Even at 80 /hr, it shouldnt take longer than a couple of hours so certainly cheaper than getting a replacement.
Chris

Charles R

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Re: A65L Crankshaft welded sludge trap access
« Reply #16 on: 07 November, 2017, 12:47:40 »
Chris

Thanks for your suggestion.

I live quite close to Draganfly so took it to them for their view.  They were very reluctant to commit to how long it would take, but their view was a minimum of 2 hours and no certainty of success in being able to reinstate it.  I could then be back to square "minus one" with a hole in the crankshaft and another one in my pocket!  I know they are quite busy, so it could be that they didn't really want to do it (though they certainly didn't say so)!

I think the answer (as recommended by you) may be to seek out another machine-shop and get their view to see what sort of process they could carry out to get into the sludge trap area to see what's in there  After inspection I could then decide what's best to do regarding making it good again or simply blanking it off (see later).

With an external cartridge filter and frequently changed modern oils, I can't see that a sludge trap would be necessary - but I'm no expert on this matter.  It seems to me that BSA put the sludge trap in the crankshaft to make use of the centrifugal effect to remove the heavier deposits in the oil but only because the filtration system was so poor.  Any thoughts on simply not bothering with the sludge trap after opening the hole to check everything is good and clean inside the crankshaft?

Cheers, Charles

Editor

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Re: A65L Crankshaft welded sludge trap access
« Reply #17 on: 07 November, 2017, 15:46:55 »
I agree that with a cartridge type oil filter the sludge trap will need cleaning out a lot less often. However, the type of deposits I've found in them when I've cleaned them out has been very fine, compacted matter. In my opinion, this will build up over a long period, how long is anyone's guess, and will need cleaning eventually.
However, I last cleaned my A65 sludge trap out about 10 years and 11,000 miles ago. It has had a cartridge type filter all this time and I don't intend to split the cases to clean it out again anytime soon. I will probably do it as it approaches 20,000 miles since the last time. I will note how much clag comes out and let everyone know, but that's likely to be in 3-4 years time so watch this space.
In the mean-time ask yourself how long you want to keep the bike and more importantly how many miles you expect to do on it in that period. After a clean out I wouldn't worry for 15-20,000 miles with a filter and that would be 7-10 years at 2000 miles a year!!
Hope this helps put it in perspective.
Chris

Charles R

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Re: A65L Crankshaft welded sludge trap access
« Reply #18 on: 07 November, 2017, 17:51:34 »
Chris

I am not intending to do any great or numerous journeys on my A65L (when eventually resuscitated) so that's part of the reasoning for not worrying unduly about the sludge trap.  I'll be very surprised if I manage more than 1000 miles a year - there could be peaks but there'll also be troughs in my use.

I also wonder whether the sludge would be fine enough and in small enough quantities to pass through the crankshaft journals without affecting them, as I would expect the filter to deal with them fairly well as they go round the oil loop.

I suppose I'm looking through rose tinted spectacles and hoping to "cure" the crankshaft block without spending a fortune or tearing out what little hair I've got left.

Hopefully my bike will be back on the road before you are able to report on how much gunge your trap has been filled with!

Thanks again for the help.

Cheers, Charles
« Last Edit: 07 November, 2017, 17:54:50 by Charles R »