Sludge Trap vs. Oil Filter

I know there are lots of discussions on the interwebs about sludge traps. My situation is this.

I have a '74 850 that has been sitting for 2 decades. It had just over 20k miles when it was parked. It also had fresh oil in it at the time. The oil looked like thin honey when I drained it. It does have an oil filter installed. Does having an oil filter delay the need to split the cases and clean the sludge trap? I currently have the head off and out for valve work. Considering taking the jugs off to check the pistons and rings.

I am really thinking that I do not need to go to the extreme of splitting the cases at this point.

I was considering doing it, but the presence of the oil filter and the fact that the single previous owner was very regimented about service and maintenance has me thinking that I may be good to go after addressing the top end.

Opinions, please. Facts, if you got 'em.

jon

I've been into a few cranks now at 30 & 40K miles and much lower mileage, plus reading and seeing sludge trap reports for over a decade now to come to conclusion that oil filers only filter out the biggest passage clogging particles of sludge and Norton can only collect at most 1/8" layer then just passes the rest through the rod ends forever more. So if rods smooth and steady on the crank then forgetabout it and let someone else deal with it some 10's of 1000's of miles later.

Triumphs must follow the motto - Clean Sludge Trap- by destroying its inspection plugs or they do tend to fill up and clog.

Best wishes the case seams are oil tight is all I'd be concerned with.

Oil filters will stop very large pieces of debris passing round a motor (but major damage will almost certainly have occurred by then anyway!) and its rather silly to think that an oil filter will actually do very much to prevent wear/engine damage.

On all air cooled motors the very best way to reduce wear to a minimum, is by regular oil changes using something like Shell Rotella oil intended for commercial diesel engines.

Splitting the cases at a reasonable mileage is recommended. Inspection of all wear surfaces, "de-coking combustion surfaces", replacement of old gaskets & seals, and through cleaning will ensure a long and happy life.

Now, what is a "reasonable mileage", you ask?

THAT can only be determined if the history is known. Oil changes, air filter maintenance, typical state of tune, duty / stresses, raw mileage, and total running hours, all play into it.

You can tell a LOT by looking at the inside of an engine. Sludge buildup, burned-on oil stains, bluing from excessive heat, hardened carbon layers, excessive and/or irregular wear patters, etc.

Yeah, so How Lucky Do Ya Feel Punk! How brave hearted or nonchalant can ya maintain riding state of mind humming along and throttling up the pull on things. Bottom ends are pretty darn robust on Nortons, so its a coin toss to avoid hassle now or get it done now while at hand and get initiated in real crank level mechanics.
My buddy Wes got away with over 50K, a few barrels and pistons/rings bores, then kept on ridding after mentioned the lose clatter sense that stopped him on night trip to a vintage meeting. They run a long time on last legs if not racing to top outs.

Standard bottom ends on Commandos may be robust, but if you are going to performance cam, pistons & rods, with any improvement on the head/porting, you'd best focus the same budget in money & effort on the crank, OR ELSE!

...and a little structural improvement on the cases sure wouldn't go amiss...

...and the tranny...

...and the chassis, and brakes...

See where this always ends up going?

You might want to do a leak down test instead of taking the cylinders off. If the numbers are good and it isn't burning oil you might just be one of those lucky ones, it happens. Ride it, sooner or later you'll have a good enough reason to get into the motor, it's not a Honda Change the filter and oil regularly and let the sludgetrap trap sludge. I don't get either-or arguments.

Just thought of something else. If you have the head off, now would be a great time to check the cam. Use a dial indicator and a magnetic stand on the cylinder, they're pretty cheap and there's plenty of other uses for them. Check the total lift of each lobe at the tappets.

If the cam shows a lot of wear then you have your reason to unbutton the whole thing

rpatton said:

Just thought of something else. If you have the head off, now would be a great time to check the cam. Use a dial indicator and a magnetic stand on the cylinder, they're pretty cheap and there's plenty of other uses for them. Check the total lift of each lobe at the tappets. If the cam shows a lot of wear then you have your reason to unbutton the whole thing

Click to expand...

Great advice and so easy to do...

grandpaul said:

rpatton said:

Just thought of something else. If you have the head off, now would be a great time to check the cam. Use a dial indicator and a magnetic stand on the cylinder, they're pretty cheap and there's plenty of other uses for them. Check the total lift of each lobe at the tappets. If the cam shows a lot of wear then you have your reason to unbutton the whole thing

Click to expand...

Great advice and so easy to do...

Click to expand...

I have never done that before and a guy on CL has a DI for $50 that is usually $130.

Does anyone have the procedure and/or pics of performing the above test?

It's pretty easy to do.
Clean the top of the cylinder.
Clean the oil out of the top of the tappets where the pushrod seats so it won't interfere with the measurement.
Drop in the pushrod and hold it so it's so that it's in its normal alignment in the cylinder, not canted.
Turn the engine through a cycle till you're sure you have found the lowest point on the cam, the base circle.
Mount the holder base on the cylinder so that the dial indicator is directly in line with the pushrod.
Experiment a little positioning the indicator till you find a point where there is no slack in the pushrod at the base circle,
the dial won't go back to zero, when you're sure you're on the base, adjust the dial to zero.
Make a few revolutions of the cam and see if you get consistent readings, you might have to apply a little pressure on the top of
the indicator because the tappets and the cam are going to have oil on them and they tend to hang up.
0.332" is the lift for both intake and exhaust.
By the time you've done the last one, you'll be an expert.
A few thou wear is normal after 20,000mi. They seem to be either OK considering the milage or really gone. You'll know it when you see it.


http://www.use-enco.com/CGI/INPDFF?PMPA ... M=326-1367

Thank you Bob. I appreciate the detailed instructions. I should be picking up the DI later today or this weekend.

Go to HF tools, usually on sale the DI is $10 and the magnetic base is $10. I have two of these setups and use them often.

I spilt the crank on two MK111 after 10K and 15 years in the barn. The sludge traps were clean.

Tom