[frogonwheels]

Hello,
I just fitted a Norton type external oil filter. This morning it was a bit cooler here in Northern California at 50 degrees than the 80 / 90 of the past weeks.
I started the bike and could see through the return in the tank that the oil was real " sluggish ". I went for a long ride, looked twice in the tank and it was just fine. Do you get that as well ? What happens if the weather dips in real low temps ? Will the oil circulate through the filter ?
Also, I just mounted an oil gauge. I think the numbers it shows are too high. After a 2 hours ride, at idle, it read 40 psi while the red stock oil pressure light was flickering.
Do you actually bleed or prime the oil line to the gauge at installation ?
The instructions didn't mention anything, I didn't do it. But would air trapped in the line increase the readings ?
Thanks.

 

[Mr.Pete]

After a 2 hours ride, at idle, it read 40 psi while the red stock oil pressure light was flickering.

Do you actually bleed or prime the oil line to the gauge at installation ?
The instructions didn't mention anything, I didn't do it.

The oil pump is a positive displacement piston pump.The return pump will pump out as much oil as gets pumped into the engine.It will also pump some air/crankcase fumes.
Put a restriction in the line and it still pumps the same amount;it just puts more load on the pump to overcome the pressure caused by the restriction.If the filter blocks,the pump will blow it to pieces,or pump the oil through (whichever comes first).

40 psi at that ambient temperature sounds about right.More likely the warning light switch is faulty.

It is a good idea to have some air space in the line to the gauge,as a cushion.It stops the pump from hammering the gauge on every pump stroke.A restriction in the line or at the gauge will help too;most gauges have a restricted inlet.The pressure pump only pumps one stroke every second revolution of the engine.Between strokes,the pressure drops.The only other cushion in the system is the OPRV piston and spring.The OPRV piston is actually pushing oil to the crank between oil pump strokes.

 

[triumpt120rv]

Hello,
What happens if the weather dips in real low temps ? Will the oil circulate through the filter ?

The cooler it gets the thicker the oil will be. I'm heading out this morning at minus 1 degree Celsius ( 30 degrees Fahrenheit). No problems for cranking and startup. When it dips to about minus 12 degrees Celsius (10 degrees Fahrenheit) kicking over gets a little tough on the knee. Last year I rode to minus 18 C. (0 degrees F.) and needed to change the oil to 10W30 to help with kicking over (unheated garage) not for circulating. Last year was a fluke because lack of snow and I never ended up storing the bike. I don't think that will be the case this year.

 

[bikeman71]

+1 Mr. Pete.

My oil pressure gauge reads about 70-80 psi when cold and falls to about 40-50 psi at idle when fully warmed up.

Its been that way since I installed the gauge and filter two years ago so your observations seem normal to me, IMHO.

 

[Snakeoil]

Any restriction to flow causes a pressure increase at that area. Thicker oil does not flow as well and hence oil pressure is higher for cold/thicker oil.

I'm not familiar with the Norton filter so not sure if there is an anti-drainback valve in them. If not, there may be a tendency for the oil to run back into sump if the scavenge pump does not seal 100%. That would mean that you have to refill the filter before you will see flow from the return line in the tank.

This is not a problem for a system with the filter on the return side of the oil supply. But it is a big deal for engines with the filter on the supply side, which is the case with most modern engines. It means you have no oil flow when you first start the engine and are relying on residual oil before the filter gets filled up. That why you don't buy cheap oil filters.

regards,
Rob

 

[frogonwheels]

Thank you gentlemen for your answers. Your time and help are always appreciated.
Gracias, Danke, Merci !

 

[tommytiger]

Just on an oil pressure related drift there is something I have been wondering.

I have always thought that good oil pressure tends to indicate good big end bearings but could it also indicate a sludge trap that is beggining to restrict flow? I've never had my crank out so have no idea of the state of the trap. When I first got the bike ( 78 tiger ) I plumbed in an oil pressure gauge and was relieved to see healthy oil pressure. Is there anyway to discern between good bearings and dodgy sludge trap?

If the engine fails to fire when I kick the engine over the oil pressure light usually goes out, does this mean anything?

 

[JohnA]

Oil light going out just by kicking over is a good sign. Staying on would be a bad sign. But those oil pressure light switches can pack up in various different ways, so shouldn't be relied upon much.

Sludge traps can be packed so full of crap you honestly wouldn't believe any oil could possibly get to the big ends - I mean, so crammed full that the sludge tube has to be drilled out, and the stuff needing to be drilled through is like solid metal/carbon matter - yet somehow the big ends can still be absolutely fine.

No idea how this works, but I know it to be a fact from experience! So, I'd say that there is very probably nothing at all wrong with your big ends, but that your sludge trap could be pretty well packed. Presumably, if a crank was never cleaned out there must come a point at which oil is cut off completely, and at that point the big end shells would fail. But they do seem unaccountably able to survive on minimal lubrication.

 

[tommytiger]

Cheers John thats what I wanted to hear. When I bought the bike I fitted an external filter kit in the return line to keep the oil cleaner and hopefully extend the period of time the trap stays clear.

Is there a mileage it's wise to have the crank out and clear the trap. I can't imagine it's a good idea to just wait for the engine to fail due to it being full. My bke has covered 20k, it had worn it's first set of piston rings out when I got it and it's on it's original bore so I think it's had a pretty normal life.

Now I got some figures from this thread I'll refit the pressure gauge and see where I'm at.

 

[JohnA]

You'll get varying responses to the 'how long before I clean out the sludge trap?' question. As you say, waiting for it to get so full the big ends melt isn't a prudent policy!

I cleaned out the sludge trap on my current TR7 just after buying it, in the knowledge that at least one of its previous owners suffered from advanced cretinism when it came to motorcycle maintenance. It had about 37000 miles on the clock, possibly genuine. The trap had a fair amount in, but nowhere near crammed full.

I hope to keep it nice and clean forever now, by using a Kirby Rowbotham pressure-fed car type filter. Cleaning out sludge traps is not a job you want to do more than once in a blue moon!

BTW, I'm sure you know this anyway, but some people ask whether they can use some sort of flushing oil or additive to clear out their sludge traps without taking them apart. The answer is a very definite no. If any such substance 'worked', in as far as it dissolved or broke up the sludge in the tube, it would cause instant disaster. The whole point of the sludge trap is to do just that, ie: trap the sludge before it can get any further. Let it out of there and where's it going next? Big end journals!

 

[Snakeoil]

There is a thread going on right now on the Honda 305 discussion group on a similar subject. For those of you not familiar with vintage Hondas, they used a centrifugal separator (sludge trap) that was a separate component, called a filter, and is designed to be cleaned out at oil changes. A gentleman who is the posterchild for anal retentive engineers has done a bunch of work on how well those types of separaters work and what variables impact their effectiveness.

Needless to say, based on the empirical data of lots of Triumph sludge traps, they work, or at least worked quite well with older oils. A concern voiced here and discussed there is Synthetic oils and their cleansing properties stripping out the muck in the trap and circulating it thru the engine. This leads me to think that if you were to put a media filter on the return line and run a true synthetic oil like Amsoil, you might end up cleaning out the sludge trap a little at a time with no detrimental impact on your engine. Maybe the impact would be akin to somebody who did not change oil as frequently as they should.

regards,
Rob

 

[Redmoggy]

Come on, using a high detergent oil to try and flush a sludge trap full of grinding paste through white metal big end bearings?

 

[DerryUK]

Something that has always troubled me with sludge traps is why do they allegedly become blocked when the relatively small oil ways leading to and from the sludge trap don't?

 

[Snakeoil]

Come on, using a high detergent oil to try and flush a sludge trap full of grinding paste through white metal big end bearings?

I hear you, Red. But given that the only filtration on these engines is the sludge trap, I tend to think we are doing that already. The question is at what rated would the syn oil dissolve the sludge? If it were a gradual process, the dirt in the oil might be no greater that it is when the oil is due for a change.

Just thinking out loud here. I'm sure there are Triumphs running with pure syn oils in them and a filthy sludge trap. I must admit that when I bought my first vintage Triumph, I was going to run syn oil until I learned of the sludge trap.

Regarding oil holes staying open and sludge trap filling up, it's an inertial separator or centrifuge type of filter. So, the spinning of the crank causes contaminants that are heavier in SG than the SG of the oil and get flung to the walls of the sludge trap wheren they hopefully stay. The effectiveness of the proces is dependent on crank RPM and the diameter of the trap. So, I would suspect that the reason that the traps never totally plug is because there is just about zero centrifugal force at the center.

Getting back to Red's objection, another thought that crossed my alledged mind is if you run Castrol, which is a high detergent oil, when your bike sits, it is safe to assume that whatver oil remains in the crank pools at the bottom of the sludge trap and continues to dissolve the sludge. So, I tend to think there is a good chance that you run a batch of lapping compound thru the big ends everytime you start a bike that has sat. Yet another reason to have a filter on the return line to trap that stuff before it gets to the tank and back into the pumps and engine.

And realize that as I'm babbling about all this stuff, I'm a guy with no filters on any of his vintage bikes. Geesh. More for the to-do list.

regards,
Rob

 

[Redmoggy]

I've asked myself similar questions Rob. The guy i got my bike off ran it for 30 years on a mixture of supermarket 20/50 (two pound fifty for five litres) and whatever he drained from bikes he was selling! I know from him and his piers that the bike had covered in exess off 150000 miles with one bottom end strip in 87.

When i took it down the trap was far from blocked but not pretty and the crank needed a tickle to 10 thou under. So, is it just down to oil selection? I have 7000 miles on a clean trap with a return line filter and am using a low detergent 20/50 for classic vehicles. It is not Motorcycle specific, i chose it as it contains more Zinc than the Motorcycle type. I intend to pull the trap at 20000 miles just out of curiosity. Then i'll decide wether to keep the filter and wether or not to fit one to the Bonnie project.

As for synthetics, i like my oil to come from Dino's.

Rod

 

[Snakeoil]

Red,

Was that a baiting effort to start another oil thread?!

The mantra that seems to show up in every oil thread on every site, be it motorcycles or cars is if you change your oil regularly and use a quality oil designed for the engine in which it is run, your engine will be happy and stay happy. That's one of the reasons why I was not putting "add oil filter" to the top of my to-do lists for the various bikes I own.

As for syn versus dino oils, the primary reason I would like to use syn in all my bikes, and by syn I mean truly synthetic and not the dino oils that meet syn specs (are you aware that some syns are really dino oils?) is for their ability to not turn acidic. I like that feature in engines that sit more than they run.

And that's all I've got to say about oil.

regards,
Rob

 

[JohnA]

Oils - what a laugh eh?! Just to add fuel to the oil-fire, I thought ALL synthetic oils are what you Yanks call Dino oils, ie: fossil or, to put it even more understandably, common crude oil-derived. If they aren't, what are they made of? And please don't just say 'chemicals'!

 

[rambo]

Oils - what a laugh eh?! Just to add fuel to the oil-fire, I thought ALL synthetic oils are what you Yanks call Dino oils, ie: fossil or, to put it even more understandably, common crude oil-derived. If they aren't, what are they made of? And please don't just say 'chemicals'!

Apparently,synth oils are made from Esters and chemicals.Anyway,my sludge trap has not been cleaned in 41 years,However,oil changes are at 1000 miles.There is never any sludge in the oil,crank is still standard.Last year,i even put a canister filter on.I use any motorcycle oil that i happen to pick up at the right price,sometimes its full synth or semi synth or even mineral.Full synth tends to make a few gasket leaks which instantly cure by then using mineral.I was talking to an old boy who ran T120s all his life and he reckoned he never had a bearing failure even when using the old oil of the 50s and 60s and neglecting it a bit.
I think the best way to go is just keep changing the oil.After all its a low cost item.If you look at Plewseys engine,he did say he neglected the oil a lot and it wears out bits now and then.However,John gives us some great videos to watch so his is the test engine !
If you strip a t120 or t140 and the cases are still clean inside,its a good sign of regular oiling

 

[Snakeoil]

Yes, real synthetics are ester based. They were originally developed by the Germans I believe, during WWII because they could not get crude. They were then further developed for use in jet engines due to the much higher temps they see in those engines. It was their ability to survive extreme temps that originally drew me to using them in air cooled engines.

Damn, you made me say more about oil.

regards,
Rob

 

[DerryUK]

<I would suspect that the reason that the traps never totally plug is because there is just about zero centrifugal force at the center>
That's the puzzle though, as it's not zero. It's describing an arc the same as the stroke of the crank. It will be zero where the oil enters the crank spindle in the timing cover though.

It would seem then that when the trap fills up no more debris is deposited there but continues to flow through the trap with the oil. Perhaps then blocked sludge traps are an urban myth (to bash newcomers and worriers over the head with) as long as you keep using your bike.

However if you bike has been laid up a long time then perhaps a full sludge trap could become consolidated and so block the flow?