Author Topic: Sludge trap  (Read 1164 times)

Offline Johnhayesuk

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Sludge trap
« on: 01.10. 2018 10:36 »
Hello my fellow experts, (not me)

Ignorance is bliss ! Where is the sludge trap on my 1952 A7 I have removed drain plug and mesh filter at bottom of engine and removed all oil from oil tank on r/h side including filter but where is this sludge trap! And what oil if the jury has returned a virdict Yore all so beautiful
John

Offline duTch

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Re: Sludge trap
« Reply #1 on: 01.10. 2018 11:12 »

 
Quote
......Yore all so beautiful
John ....

 Well maybe the others are but I'm not as I have the news you don't wish to hear... the sludge trap is in the bowels of the crank, which entails deep surgery to access.... is under the big-ends.... sorry,  they didn't like me at school either


Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline a10gf

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Re: Sludge trap
« Reply #2 on: 01.10. 2018 11:14 »
Hello, yes, inside the crank & needs disassembling of engine.

see https://www.a7a10.net/forum/doc/parts/BSAA7_A10_1949_to_1953_Spares.pdf
page 11, location behind the 'plug', part 58

When you are at it, after opening Spares.pdf, save it to your computer, so as to always have it available.

Use search, sludge trap, lots of good reading and info about this important maintenance task (thankfully not often it's needed, but if maintenance history of engine is not 100% known, sludge trap has to be checked).

I remember mine, was nearly full of 'something' that had completely petrified like cement, oil flow must have been getting close to nonexistant. Glad I checked and cleaned it.

Direct link to sludge search results

A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Offline Swarfcut

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Re: Sludge trap
« Reply #3 on: 09.10. 2018 21:07 »
  May be a bit late now, but here are a few pictures of a clogged sludge trap and a crankcase showing the consequences of not cleaning it out. Any help needed, just ask. Sleep tight!    Swarfy

Offline Steverat

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Re: Sludge trap
« Reply #4 on: 16.10. 2018 06:43 »
OMG I can see I shall have to do a cleanout on Josef's A10 before reassembly. I have the crank out already, the sludge trap plugs don't have any slot in them however. Maybe I'll drill them in the middle and try a fat thread extractor. But once I have them out, this is an early crank so no tube in it, how shall I ensure I've got all the sludge out??

1951 BSA A10 - now returned to Germany
1972 Triumph T100R Daytona
1924 B-S SS80
1965 Triumph SH Cub
1960 AJS M18CS

Offline duTch

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Re: Sludge trap
« Reply #5 on: 16.10. 2018 07:17 »

 
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.....how shall I ensure I've got all the sludge out??...

 Fairly self evident, you won't see anything other than a hollow, but ensure you clear the gallery between the main journal and big ends-I used a wire brush from a gun shop.....  Replace the plugs with socket wrench types, like SRM sell. 
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online Greybeard

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Re: Sludge trap
« Reply #6 on: 16.10. 2018 07:52 »
Replace the plugs with socket wrench types, like SRM sell.
When putting the new plugs in make sure they are not inserted too far and so partially blocking the oilways.

Offline Swarfcut

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Re: Sludge trap
« Reply #7 on: 16.10. 2018 09:10 »
 Hi Steverat...If any single aspect of the design of the A10 has ever been neglected or misunderstood, it is the "Sludge Trap". On a small journal crank it really is just just a simple oilway leading from one big end to the other. Unfortunately this is where all the low life found in your motor congregates to cause trouble. This is how I do small journal cranks. Basic technique applies to big journal cranks, but they have a tubular trap that really does trap the sludge.

   I will assume you have some basic knowledge, you may be a time served machinist, apologies if this is a trip down memory lane.

   First, measure the journals. Has the crank any life left? Is it worth proceeding. Can you get new bearing shells?

     If your plugs have no slots, that is unusual. How would they be turned into place? Could they be some just some  bodge by a previous owner, like a couple of  metal corks hammered in?

    Have a good dig, there should be a slot across the middle, plus 2 or 3 punch marks to lock the plug in place.

    Getting them out is easy. First treat yourself to a new set of drills. My favourites are a cheap set of cobalt drills from Toolstation.

    Support the crank well, and talk to it. Let it know you have a new set of drills, you are in no mood to be gentle, the end of the world is coming, and you, plug with no married parents, are coming out.

   The aim is to create the least amount of damage, so we start gently and work up into a frenzy of violence and desperation no plug can resist.

    Next, drill  very gently into the punch marks with your smallest drill. The aim should be to remove metal from the plug, not the crank.  When you have done some exploring, drill the punch marks with bigger drills until you are sure they are no longer effective, making sure you do not drill the crank.

    Now you need the biggest flat blade screwdriver......I use one on a 1/2" square socket drive.   With the crank well supported, put the blade in the slot  and give  it a good smack to let the plug know the pain is coming and jarr the thread and hopefully help start it on its way out.   No luck?   Try an impact driver, but the blade size on these is smaller and you may damage the slot.

    Next, try a bit of heat. Butane, Propane torch, Oxy- acetylene if you have it.  This is where I generally have success and out it comes, normal right hand threat, lefty loosey anti clockwise to undo.

   No slot, or  slot already wrecked?  Drill a  nice hole in the middle but do not use a stud extractor.  Typically these spread the plug further the deeper they go  so will tend to make it more difficult to remove..  Instead try a  big TORX bit, hammered into a slightly smaller hole.   Still no good?  If you feel confident, put a bolt in the hole and and tack weld it to the plug. The heat of welding a bolt to the plug will help loosen it and you also have something to put a spanner on.

   Still no good?  Big Drill Time!.  Enlarge the centre hole with your ever increasing size selection of new drills until you are left with just a thin threaded cylinder, thin enough to collapse into the hole.

  Remember, try not to damage the crank.  Before grabbing a well deserved beer,  take a few pictures  to remind you of one of the most memorable days of your life.

  You will be amazed at the small size of the oilway. Easy to clean,  just a straight drilling. New plugs are available, or get some made, thread size somewhere on this Forum.

  Good Luck with it.

   Keep Spannering,  Swarfy.

Online Rex

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Re: Sludge trap
« Reply #8 on: 16.10. 2018 09:32 »
I couldn't find any hex plugs for my 1951 A7...slotted were the only ones available.
Due to either/or the replacement plug thread not fitting nicely with the 67 year old thread in the crank I had to lap the new plugs in until they were able to be screwed flush. I had to index the plug with the crank oil way and remove some metal from the plug to prevent the plug partially obscuring that oilway too.

Offline Swarfcut

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Re: Sludge trap
« Reply #9 on: 16.10. 2018 09:45 »
 Rex, Thanks for that timely reminder concerning the quality of replacement parts. As Greybeard remarked, screwing a plug too far in will obstruct the oil feed to the journals.  Good job you noticed , lots of folks wouldn't.  Shame they can't be made right first time. It would be more profitable, thinner plug, less material.  Balance factor? Out of balance from standard anyway, once the carbon is on the piston crowns.

  Swarfy.


Offline Steverat

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Re: Sludge trap
« Reply #10 on: 16.10. 2018 20:33 »
Thanks Guys,
Josef's plugs were blank, no slots. So I had to drill the centre for an extractor. Lucky me - they came out without too much swearing. SRM have promised to send some new plugs with hex sockets so thats all nice.

1951 BSA A10 - now returned to Germany
1972 Triumph T100R Daytona
1924 B-S SS80
1965 Triumph SH Cub
1960 AJS M18CS

Online Greybeard

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Re: Sludge trap
« Reply #11 on: 16.10. 2018 22:58 »
Well they were not meant to come out easily were they. Must have screwed in a stud or bolt and just hack-sawed the end off

Offline Swarfcut

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Re: Sludge trap
« Reply #12 on: 17.10. 2018 09:14 »

 Steve,  you are indeed a lucky man. Here's me thinking you would need a bit of help.  Bear in mind there are two sizes of plug,  Small Journal...Small Plug.. Big Journal Cranks have a bigger diameter. Hope you have ordered the right ones. What did you find?

  Swarfy.

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Re: Sludge trap
« Reply #13 on: 17.10. 2018 09:56 »
Thanks Guys,
Josef's plugs were blank, no slots. So I had to drill the centre for an extractor. Lucky me - they came out without too much swearing. SRM have promised to send some new plugs with hex sockets so thats all nice.
How much muck was under those plugs?

Offline Steverat

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Re: Sludge trap
« Reply #14 on: 17.10. 2018 22:21 »
There was a teaspoonful of sludge altogether - enough to be dangerous I think.

Yes got some new plugs with hex sockets for small bearing cranks from SRM. They were very good and quick too, the plugs are here already.

1951 BSA A10 - now returned to Germany
1972 Triumph T100R Daytona
1924 B-S SS80
1965 Triumph SH Cub
1960 AJS M18CS