Ironhead Side bag Oil filter

[brucstoudt]

it seems the xlch owners with the horseshoe oil tank have little choice other than the spin on filter on the front motor mount [theres that catch 22,thing again]

[IronMick]

Originally Posted by brucstoudt

it seems the xlch owners with the horseshoe oil tank have little choice other than the spin on filter on the front motor mount ...

I got this oil filter mount with my basket case, bottom left of pic ...

[cajun1957a]

So Dr. Dick, the best filter is the original filter and not the newer style filters? Also I dont have a dipstick on my cap, is this detrimental if i go to the old style filter? You said there is a releif valve on that. Are those caps still available?

randy

[brucstoudt]

i,have all 4,of the easyriders tech tips books,and they compare the fiberglass in tank,with the spin-on canister style,and the spin-on did a,much better of filtering the oil,micron,vs.micron.which makes the statement,least favorite post highly,possible.[nothing was mentioned about filtering vs.flow,by the way.]

[brucstoudt]

[QUOTE=IronMick;3878022]I got this oil filter mount with my basket case, bottom left of pic ...

thanks mick,i,saw that with the thread.i,prefer the one i,have,mounted on the front motor mount

[Hopper]

Originally Posted by DR DICK

[SIZE=4][SIZE=2]...
some of you guys will know when the first oil cooler appeared on a factory bike. but many of ya wont. if you do know then you also know it was piped into the supply side.
not the return.
strange right?
stranger yet that cooler was installed between the top end feed fittings on crankcase and the rocker box supply fittings.
why?
because interfearing with the return system was gonna just add to the prob that the new cooler was trying to fix.

At least some of them used a cooler on the return line as well. Those waffle irons ran so hot I remember reading press reports at the time that they were running as low as 6.7 to 1 compression to try to get the pistons to stop seizing due to overheating with the iron heads and barrels.

But as far as filters reducing flow etc, the gerotor and gear pumps are positive displacement, minus a small percentage that leaks past the rotor/gears due to wear, so no matter if a filter provides some restriction, the pump will push the oil through that filter at the same number of gallons per minute, albeit at a higher pressure. The pump still removes the same quantity of oil from the 'sump' per revolution, no matter what the restriction on the filter is. It just uses more horsepower to do so, which would be a concern for racing.

That's why its common engineering practice to put a blow-off valve on oil filters, like the stocker and some of the aftermarket pleated ones have: if the filter is allowed to get so dirty it clogs completely etc, that positive displacement pump will keep pumping until pressure reaches point where it blows a hose, or shears the drive key/pin in the pump, unless there is a pressure relief valve. Same situation might occur with cold heavy oil on start up maybe, or like said at peak rpm for sustained periods with restrictive filter.

[DR DICK]

what ever filt you use is up to you. just use one. not having them deff takes it toll on road bikes in the long run.

ive used every kind. and i have found that the spin on are too cheaply made and they may have relief valves that didnt allways work. not stuck closed but stuck open. rendering the filter useless. you may get 20 unit that work fine and then one bad unit.

if someone has the mindset that return restristion is small potatoes for the way he rides he very well may be correct. if you have no probs there isnt any thing to fix.

on bikes whos owners were the type who wanted everything on to work as best as they reasonable could attain- well on those we would make up an external relief and pipe it in front of the filt/cooler. so now you wernt rollin the dice on the the operation of what ever filt was gonna be used. made those reliefs from the stock unit.

what i like is a filter i can dismantle ans see what its catching. i used to make little canisters that took the glass elements and the stock relief valve that id mount behind the left rear shock on the fenderrail/frame bolt.

concerning positive displacement pumps.
dont take that term literally. compared to a centrifigal pump gear type pumps use displacement to function. how positive it is depends on what it pumping.

the most 'positive' pump on our bikes may be the master cyl for the disc brakes. you pull the lever and it pumps real good. positive.

unless there is air in the system. than you still get the displacement but not the pressure. because liquid is not compressable but air is.

gear type pumps work by filling the spaces between the teeth with whatever it is that is being pumped. oil in our case.
that oil in the tooth spaces gets squezed out of the spaces when the gear teeth mesh together. becasue a tooth is now in that space.

but there is still a little space left at full mesh. gearotor pumps have a smaller space at full mesh than gear pumps.

now when the mesh breaks a void is created. oil gets sucked into that void. so far so good.

now what if air is in the spaces instead of oil?
its gets sqeezed out to. unless there is pressure (restriction) in the curcuit its trying to flow into. in that case some air stays in spaces. and gets compressed in small space remaining as the teeth mesh.

when teeth unmesh air expands. refilling void that should be gettin oil sucked into it. pump cant make enuff pressure to overcome exit restriction. no flow. and no ability to reprime itself because it aint makin enuff suction due to expansion of the compressed air refilling the void that the oil should be filling.

eventually the press in return line from filter restriction get relased as oil bleeds thru element. while this is happening oil is building up in the pickup sump. oil is building up waiting for return pump to come back online because the supply pump is still pumpin while the return is toggling from air locked to primed and pumping.

think about the state the return oil is in as it collects in the return pickup cavity. its just been thru a 60ci blender. ever get the 1st mugfull from a just tapped keg? your bike lives with that every mile it travels. lots of air whipped into every drop of return oil.

if the restriction in the return is large enuff to reduce outflow from engine to a volume less than the supply pump is feedin into engine you have--- you got it--- more oil going in than going out. welcome to wetsumpville. the town where we work harder to get less done.

you cant tell this is happening riding down the road. but your motor is working harder if it is.

so in my mind the best way to deal with a cold is to avoid putting your self where you might catch it in the 1st place.

the return side cooler on the r models;
if you look hard enuff you will see all kinds of mods to the cooling of the oil.

but the bikes that won races by havin less hp sucked up from the above more often than not had a 2nd oilpump installed where the production bikes carry ignition drive in camcover. feeding cooler and, belive or not, filters in some cases. yes this2nd pump sucked up power. but it didnt restrict the scavenging outflow..

filters and coolers are good!!!

its up to you to see that they dont create more probs than they prevent.

a false sense of security is exactly that.

do you really belive that sifton went to crap and there are counterfiet hi perf part being hocked, and you cant get decent kicker parts, but your filter supplier is run by a bunch of nuns?

[Hopper]

Good point about the effect of air on positive displacement pumps Doc. As always with these old engines, nothing is cut and dried.
Re Sifton parts, all I know is they are not USA made any more.
And the nuns who make the drop in pleated filters I use put a spring loaded relief valve in the bottom of the filter, so I am happy with the job they do, bless their little hearts.
Like you say, horses for courses and for general touring riding, they work fine for me.

[ericfreeman]

I've got a bunch of drop in pleated filters for my '77 and '78 and also have a very accurate low-pressure air regulator at work. Think I'll take a new filter, rig up a way to close it off and see at what pressure the relief valve opens. Should be interesting to see.

Eric

[Hopper]

Originally Posted by ericfreeman

I've got a bunch of drop in pleated filters for my '77 and '78 and also have a very accurate low-pressure air regulator at work. Think I'll take a new filter, rig up a way to close it off and see at what pressure the relief valve opens. Should be interesting to see.

Eric

Good idea! Would be good to know.