BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: Mike Farmer on 30 Dec, 2019, 09:51

Title: Sludge traps
Post by: Mike Farmer on 30 Dec, 2019, 09:51
 :) :) :)
Just picking up on a previous post on the subject of the sludge trap.

My thoughts are that with an in line oil filter fitted your sludge trap is probably redundant. However if you run the motor without it you may seriously unbalance the crank.

Mike 8) 8) 8)
Title: Re: Sludge traps
Post by: ducati2242 on 30 Dec, 2019, 13:48
surely if you run without the plug , if thats what you mean , then you will have no oil pressure .
Title: Re: Sludge traps
Post by: Mike Farmer on 30 Dec, 2019, 19:22
 :) :) :)

No I meant running without the actual sludge trap tube fitted. Another thought on this same point is that when the trap is abso bunged with crud that too will unbalance the crank.

Mike 8) 8) 8)
Title: Re: Sludge traps
Post by: Bess on 30 Dec, 2019, 20:09
Hi Mike,
             My thoughts:

The filter is in the return so the sludge trap is still relevant.
Not sure if it would seriously unbalance the crank, maybe slightly as oil would replace the area of the tube.

Best wishes...
Title: Re: Sludge traps
Post by: ChrisG on 02 Jan, 2020, 17:25
I had a pre OIF Thunderbolt with no ST tube in there. During the rebuild I didnt look at the manual so didn't know there should be one. I just cleaned out the hole and put it back together. It never caused any problems in the year or so I was still the keeper and I added an inline filter during the rebuild. However, until a serious mileage is achieved, who knows what the impact may be?

I had the crank balanced (without the tube) and it still vibrated badly. However, this may have been due to the Balancing guy I used, was the sub contractor to SRM at that time. A few months later SRM brought the process in house - reason they told me was said balancing guy was next to useless or similar words. (This was in the mid nineties).