Topic: Crankshaft sludge trap - Steel balls

[KirkBurner]

Where do I get these balls?

I was going to try the grub screw approach but broke the tap..... manage to get the tap out (well a more patient friend did it for me)

so... I rather go back to the ball approach?

anyone got any tips on the ball size? cause the machineshop couldnt help me..  they have kinda disapointed me the last times I have used them, I might have to go look for another shop.....

[lrutt]

what bike is this? Never heard of a sludge trap on an SOHC

[bwaller]

You know what they say....you can't go back!

[Bodi]

The oil passages through the crankshaft to feed lubricant to the rod end bearings have to follow the shape of the crank: various intersecting holes are drilled and the resulting open ends capped with pressed-in steel balls. That leaves dead end passages which fill with dirt particle "sludge" especially in radial holes where the stuff is pressed into the "dead ends" by centrifugal force.
Cleaning them out gives a sense of accomplishment but does nothing worthwhile. The trapped sludge is, well, trapped.
Much like with most furnace duct cleaning, you're removing dirt that won't re-enter the normal flow.

[Whaleman]

Bodi, I also have always thought this. The main passageways will stay clean with proper oil changes and the pressure flow. A case could be made that the oil flow will be smoother WHEN the side passageways completly fill with sludge. Dan

[KirkBurner]

http://forums.sohc4.net/index.php/topic,146287.msg1664725.html#msg1664725

this is what I was trying to do, and the broken tap kinda scared me away from going down this road.. after the machineshop guy said that he wouldnt try to tap a forged crank...

but hey I dont know what I am doing...

is it easy to tap the crank or not?

[lrutt]

For those of us in the Brit bike world, Triumphs and Nortons have a true sludge trap who's purpose is to capture all the crap as there were no filters. This guaranteed a complete tear down to crank about every 20k miles or so. Well documented.

Thus my confusion when used in reference to SOHCs

[KirkBurner]

No worries... this engine I am rebuilding hadd some really ugly worn bearings that could very vell indicate an oil flow issue.. thats why I had this part thoroughly cleaned.

as for the Norton/Thriumph issue .. does this apply for BSA's aswell.. they have started to gather som interest on my part.

[Garage_guy_chris]

The tapping is very slow going and difficult. I found i could only get 1/4 turn then back it off to break the chips. then go forward another 1/4 turn then back. then completely remove the tap every full turn to clean off the chips and relubricate. I was gonna update my thread with a tapping proceedure today.

As for reinstalling balls i dont know how successful you will be in doing so or finding somebody to do it. everybody seems to do the grub screw approach. If i were you i would get a good quality tap and someone experienced and finish the tapping and grub screws. Also you didn't mention drilling the passage up to the proper tap drill size (#3 drill)

[KirkBurner]

Thanks Chris..

I guess I will have to get another tap then...  then just go real slow.

[MRieck]

Some tap lube helps a lot.

[Garage_guy_chris]

I updated the thread now, tapping/cutting oil is so second nature to me i dont even think about it but good point MRieck.

[lrutt]

No worries... this engine I am rebuilding hadd some really ugly worn bearings that could very vell indicate an oil flow issue.. thats why I had this part thoroughly cleaned.

as for the Norton/Thriumph issue .. does this apply for BSA's aswell.. they have started to gather som interest on my part.

Yes.. As for BSA's, watch the year and timing side bearings. Lots of issues on earlier ones and retrofits available to needles to solve oil pressure problems.

[Muckinfuss]

I owned a few BSA's back in the 60's and 70's.  The definition of high maintenance.  You have to be addicted to them to appreciate them.  Just like high maintenance women.